Module 2 General principles of metabolism. Мetabolism of carbohy-drates, lipids, amino
acids and its regulation
Test questions in text form
1. ______________ is a cosubstrate.
A. * Tetrahydrofolate.
B. NADH
C. Biotin
D. Thiamin pyrophosphate.
E. Pyridoxol phosphate
2. ________________ can bind to the free enzyme.
A. * A competitive inhibitor
B. A uncompetitive inhibitor
C. A non-competitive inhibitor
D. a and c
E. b and c
3. _________ is the coenzyme involved in decarboxylation reactions.
A. Tetrahydrofolate.
B. NADH
C. Biotin
D. Thiamin pyrophosphate.
E. * Pyridoxol phosphate.
4. _____________ alters the Vmax of an enzyme.
A. A competitive inhibitor
B. * A uncompetitive inhibitor
C. A non-competitive inhibitor
D. A and c
E. B and c
5. _____________ binds to the enzyme at sites other than the substrate binding site.
A. An allosteric inhibitor
B. * A uncompetitive inhibitor
C. A non-competitive inhibitor
D. A and c
E. All of the above
6. ____________________ is the term that describes a theoretical value achieved when all
enzyme substrate binding sites are occupied by the substrate.
A. Km
B. Kcat
C. Vmax
D. * kcat/ Km
E. mg
7. (k-1 + kcat)/k1 = _________.
A. Vmax
B. * Km
C. Kcat
D. Kcat/Km
E. All of the above
8. A catalyst can promote product formation during a chemical reaction by _____.
A. Lowering the activation energy barrier.
B. Stabilizing the transition state.
C. Positioning reactants in the correct orientation.
D. * Bringing reactants together.
E. All of the above
9. A catalyst can promote product formation during a chemical reaction by _____.
A. Lowering the activation energy barrier.
B. Stabilizing the transition state.
C. Positioning reactants in the correct orientation.
D. * Bringing reactants together.
E. All of the above
10. A column packed with the sieved particles are used in which of the following techniques
to separate smaller and larger protein molecules
A. Affinity chromatography
B. Electrophoresis
C. * Molecular exclusion chromatography
D. Selective adsorbtion
E. All of these
11. A competitive inhibitor binds to
A. Substrate
B. * Active site
C. Allosteric site
D. Enzyme-substrate complex
E. Coenxyme
12. A reaction is designated as exergonic rather than endergonic when ___________.
A. Activation energy exceeds net energy release
B. Activation energy is necessary
C. No kinetic energy is released
D. * The potential energy of the products is less than the potential energy of the
reactants
E. It absorbs more energy
13. A reversible inhibitor that can bind to either E alone or the ES complex is referred to as a
_____.
A. Competitive inhibitor.
B. * Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. Irreversible inhibitor
14. A reversible inhibitor that only binds to the ES complex is referred to as a _____.
A. Competitive inhibitor
B. Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. * Irreversible inhibitor
15. A thermodynamic pit occurs when
A. ES is not very stable
B. ES forms faster than it dissociates
C. * ES is highly stable
D. S is not bound tightly to an enzyme
E. S is positioned incorrectly to the enzyme
16. According to the second law of thermodynamics, which of the following is true?
A. The total amount of energy in the universe is constant.
B. Energy conversions increase the order in the universe.
C. The ordering of one system depends on the disordering of another.
D. The entropy of the universe is constantly decreasing.
E. * All reactions produce some heat.
17. Active holoenzymes are formed from ____________ in the presence of _________.
A. Cofactors; proteins
B. Proteins; cofactors
C. * Apoenzymes; cofactors
D. Apoenzymes; proteins
E. Apoenzymes; inactive holoenzymes
18. An allosteric inhibitor of an enzyme usually
A. Binds to the active site.
B. * Participates in feedback regulation.
C. Denatures the enzyme.
D. Causes the enzyme to work faster.
E. Is a hydrophobic compound.
19. An enzyme is said to be catalytically perfect when _______.
A. It has a large Km
B. It has a small kcat
C. * Its kcat/Km value is close to that of the diffusion limit
D. It has very high affinity for the transition state
E. All of the above
20. An enzyme is specific. This means
A. It has a certain amino acid sequence.
B. It is found only in a certain place.
C. It functions only under certain environmental conditions.
D. It speeds up a particular chemical reaction.
E. * It occurs in only one type of cell.
21. An update of Fischer's lock and key theory of enzyme specificity view the _______ as the
lock and _______ as the key.
A. Enzyme; substrate
B. Substrate; enzyme
C. * Enzyme; transition state
D. Transition state; enzyme
E. Substrate; transition state
22. By efektors can forward some substance, except:
A. Hormones
B. Mediators of the nervous system
C. Metals
D. Products of enzymatic reactions
E. * Vitamins
23. Ca++ or Mg++ are most likely to be part of ___________, while Zn++ or Fe++ are
present in _______________.
A. * Metal-activated enzymes; metalloenzymes
B. Metalloenzymes; metal-activated enzymes
C. Cofactors; coenzymes
D. Coenzymes; cofactors
E. Apoenzymes; holoenzymes
24. Conserved serine, histidine and aspartate residues are present in the catalytic center of all
serine proteases. Which of the following describes the role of the histidine residue in the
mechanism of this reaction?
A. * Covalent binding of acyl groups
B. Hydrophobic stabilization of the substrate
C. Proton transfer
D. Cation binding
E. Anion transport
25. Consider a hypothetical metabolic pathway for the synthesis of the amino acid arginine:
precursor A intermediate B arginine. Each reaction is catalyzed by a different enzyme.
This metabolic pathway is controlled by feedback inhibition with arginine inhibiting the
conversion of precursor A to intermediate B. In this case, arginine almost certainly acts
as a _____ of the first enzyme in the pathway.
A. * Substrate
B. Competitive inhibitor
C. Catalyst
D. Cofactor
E. None of the above
26. Covalent modifications that increase the activity of allosterically regulated enzymes do so
by ______________.
A. * Adding phosphate groups to essential amino acids in the active site
B. Causing the enzyme to fold into a more active configuration
C. Increasing the amount of total enzyme present
D. None of the above
E. All of the above
27. During allosteric, or feed back, inhibition
A. Transcription of mRNA specific for the enzymes involved in the pathway is
repressed by the pathway's end product.
B. Enzyme concentrations in the cell remain relatively constant.
C. * The pathway's end product represses the activity of the first enzyme in the
pathway
D. All of the above apply to feedback inhibition.
E. More than one of the above, but not all, apply to feedback inhibition.
28. During electrophoretic research of LDG in the blood serum found out predominance of
content of LDG1 and LDG2. Pathology of what organ does these information testify?
A. Lungs
B. * Heart
C. Liver
D. Musculs
E. Spleen
29. During enzyme repression
A. The pathway's end product represses the activity of the first enzyme in the
pathway.
B. B.Enzyme concentrations in the cell remain relatively constant.
C. Transcription of mRNA specific for the enzymes involved in the pathway is
repressed by the pathway's end product.
D. * More than one of the above, but not all, apply to feedback inhibition.
E. All of the above apply to feedback inhibition.
30. During feedback inhibition, the effector molecule binds to the enzyme's ___________
site
A. Permissive
B. Alternative
C. Allosteric
D. * Conformational
E. Active
31. Energy-requiring reactions can occur in biological systems because enzymes allow their
coupling to other reactions with:
A. The activation energy of the reaction is doubled.
B. The activation energy of the reaction is lowered.
C. It's optimal conditions for temperature of the enzyme are doubled.
D. * The shape of the enzyme molecule is changed.
E. All of above
32. Enzymes that are allosterically regulated ____________________.
A. Are multimeric proteins
B. * Possess regulatory and catalytic domains
C. Do not behave according to the Michaelis-Menton equation
D. All of the above
E. Are monomeric proteins
33. Enzymes:
A. Are composed primarily of polypeptides, which are polymers of amino acids.
B. * Can bind prosthetic groups such as metal ions that participate in enzyme
reactions.
C. Have defined structures.
D. Bind their substrates at active sites.
E. All statements are true.
34. Ethanol (CH3CH2OH) is the alcohol found in beverages. It is oxidized in the body to
acetaldehyde by the enzyme alcohol dehydrogenase. Methanol (CH3OH), also known as
wood alcohol, is converted to formaldehyde by the same enzyme. Acetaldehyde is toxic,
but formaldehyde is far more toxic to humans, which is why the ingestion of relatively
small amounts of methanol can cause blindness or death. One treatment for mild
methanol poisoning is the administration of ethanol. Why might a doctor choose this
treatment?
A. Ethanol must act as a competitive inhibitor for the alcohol dehydrogenase and
therefore slows the formation of formaldehyde.
B. Ethanol likely irreversibly binds to alcohol dehydrogenase which prevents the
formation of formaldehyde.
C. * The ethanol is likely an uncompetitive inhibitor and binds to a site other than
the active site of the enzyme.
D. The doctor has given up on the patient and administers ethanol for sedation
E. B and C
35. If it is known that the only two ionizable residues in the active site are both glutamates,
which conclusion can be drawn?
A. * The glutamates have different microenviroments which cause their pKa's to
differ.
B. One of the glutamates must be amidated.
C. Both glutamates have a pKa equal to 5.0.
D. Both glutamates are deprotonated during the reaction.
E. B and C
36. If the tertiary structure of an enzyme is changed _____.
A. * Its substrate may not fit properly in the active site
B. It will be missing one of its polypeptides
C. The helical coil will be stretched out
D. The product of the reaction will be a different molecule
E. Its substrate will bond covalently with the wrong part of the molecule
37. In a multienzyme complex the process of directly transferring a product of one reaction
to the next active site without allowing it to enter the bulk solvent is termed _______.
A. a ping-pong reaction
B. * metabolite channeling
C. the activity pathway
D. the sequential mode
E. All of the above
38. In a ping-pong reaction which does not occur?
A. One product is released before a second substrate is bound.
B. The enzyme covalently binds a portion of the first substrate.
C. * The enzyme is permanently converted to an altered form by the first substrate.
D. A group is transferred from one substrate to another.
E. All of the above
39. Izoenzymes differ between itself some physical and chemical properties, except:
A. Electrophoretic mobility
B. Molecular activity
C. Stability
D. * Present in different tissues
E. Difference their primary structure
40. Mg2+ is used as a(n) by metal activate enzymes that utilize negatively charged substrates
like ATP.
A. Metalloenzyme
B. * Activator ion
C. Prosthetic group
D. Co-substrate
E. Ingibitor ion
41. R-CH2OH + O2 > R-CHO + H2O2 which of the following types of enzymes catalyzes
this reaction
A. Dehydrogenase
B. Oxidase
C. * Peroxidase
D. Aldolase
E. Catalase
42. Some antibody molecules are enzymatic if they are formed against
A. Enzymes
B. Enzymes bound to other proteins
C. * Transition state analogs bound to other proteins
D. Transition state analogs
E. All of the above
43. Specificity of enzyms is conditioned by the following factors, except:
A. Conformation complementare
B. Electrostatic complementare
C. The feature structure of active center of enzyme
D. * The feature structure of allosteric center
E. Proteins nature
44. ?The active site of an enzyme differs from an antibody-antigen binding site in that the
enzyme active site
A. Contains modified amino acids
B. Catalyzes a chemical reaction
C. Is complementary to a specific ligand
D. * Contains amino acids without sidechains
E. None of the above are correct
45. The assumptions made in calculating the Michaelis-Menten Equation include
A. That the formation and decomposition of ES is the same for a period of time
B. That the concentration of the substrate is much greater than the concentration of E
C. That the value of k-2 can be ignored
D. * a, b and c
E. a and b
46. The catalytic triad of chymotrypsin and other serine proteases are
A. Three subunits of the enzyme.
B. Three adjacent amino acid residues which act to make serine a strong nucleophile.
C. * Three amino acid residues close enough together to make serine a strong
nucleophile.
D. Three enzymes with very similar structural features.
E. All of the above
47. The concentrations of enzymes is determined by using pseudo first-order conditions in
which
A. concentration is kept the same and the rate is measured
B. concentration is kept the same and the rate is measured
C. * concentration is constant, E concentration varied and the rate is measured
D. concentration is constant, S concentration varied and the rate is measured
E. All of the above
48. The data shown on the graph were obtained for a kinetic experiment. What type of
inhibition is it?
A. Competitive
B. Uncompetitive
C. * Noncompetitive
D. Irreversible
E. A and B
49. The enzyme has an active site which
A. Fits the substrate exactly
B. Fits the transition state
C. May contain hydrogen bonds which are covalent like
D. a and c
E. * b and c
50. The equilibrium constant for the reaction, glucose 6-phosphate + water T glucose +
phosphate, is 260. What can you conclude about this reaction:
A. It is a closed system
B. It never reached equilibrium.
C. Starting with glucose 6-phosphate, it is not spontaneous.
D. * At equilibrium, the concentration of glucose is much higher than the
concentrations of glucose 6-phosphate.
E. At equilibrium, the concentration of glucose is much higher than the
concentrations of phosphate
51. The mechanism of enzyme action is _____.
A. * To create an energy barrier between substrates
B. To lower the energy of the activation of a reaction
C. To change the direction of thermodynamic equilibrium
D. To change endergonic into exergonic reactions
E. To allow substrates to move more freely in solution
52. The Michaelis constant, Km, is
A. The maximum velocity that any given enzyme reaction can achieve
B. The substrate concentration which gives the best enzyme assay for an enzyme
reaction
C. * The substrate concentration when the reaction is half the way toward the
maximal velocity
D. The maximal velocity divided in half
E. All of the above
53. The rate of a second order reaction depends on the concentration of _________.
A. One substrate
B. * Two substrates
C. Three substrates
D. None of the above
E. Ten substrates
54. The result of a(n) __________ reaction is that energy is released. Energy must be added
for a(n) __________ reaction to proceed.
A. Enzyme catalyzed, non-spontaneous
B. * Exergonic, endergonic
C. Endergonic, spontaneous
D. Catalytic, non-catalytic
E. Oxidative, hydrolysis
55. The steady state assumption for Michaelis-Menton kinetics assumes that ______.
A. * The concentration of the ES complex is constant
B. The rate of ES formation is faster than the rate of ES disassociation
C. k1 = k-1= kcat
D. The concentration of the ES complex is increase
E. None of the above
56. The term ligase refers to a class of enzymes that catalyzes_________.
A. Oxidation reduction reactions
B. Reactions involving the transfer of a functional group from one molecule to
another
C. Hydrolytic cleavages
D. * Reactions where two molecules are joined together
E. All of the above
57. The time that is required for an enzyme to convert one substrate molecule into one
product molecule is
A. Km
B. kcat
C. 1/Km
D. * 1/kcat
E. 1 min
58. The Vmax of an enzyme changes when the enzyme is treated with a_____.
A. Competitive inhibitor
B. Uncompetitive inhibitor
C. Noncompetitive inhibitor
D. A and b
E. * B and c
59. Two curves showing the rate versus substrate concentration are shown below for an
enzyme-catalyzed reaction. One curve is for the reaction in the presence of substance X.
The other curve is for data in the absence of substance X. Examine the curves and tell
which statement below is false.
A. X is an activator of the enzyme.
B. The enzyme kinetics are non-Michaelis-Menton.
C. X is likely an allosteric modulator.
D. * X is a competitive inhibitor.
E. None of above
60. What shape would a graph of reaction velocity versus pH have for an enzyme that uses
both a proton donor and a proton acceptor during catalysis (both acid and base catalysis)?
A. Sigmoidal
B. Hyperbolic
C. Exponential
D. * Bell-shaped
E. Linear
61. When the concentration of a substrate inside a cell falls below the substrate concentration
at half maximal velocity,
A. ES is formed more easily
B. * ES dissociates to E + S
C. ES is closer to the ground state than to the transition state
D. E + S is in equilibrium with ES
E. The reaction will not proceed
62. When the rate of an enzymatic reaction is controlled by the amount of enzyme present,
which of the following factors controls enzyme levels?
A. Rates of transcription
B. Rates of translation
C. Rates of protein turnover
D. Rates of mRNA turnover
E. * All of the above
63. Which cofactor has the following properties: a) forms Schiff base, b) its precursor is
absorb dietarily as Vitamin B6, c) is required in a number of reactions in aminoacid
metabolism.
A. Thiamin pyrophosphate
B. Biotin
C. Lipoamide
D. * Pyridoxal phosphate
E. Nicotinamid
64. Which from the adopted enzymes can united in polienzymes complexes?
A. * Pyruvatdehydrogenase
B. Transketolase
C. Suktsinatdehydrogenase
D. Al'dolase
E. Glukos-6-phosphatase
65. Which is not a reason for metabolite channeling?
A. Protection of intermediates from degradation.
B. Increasing the overall rate of a reaction.
C. Producing locally high concentrations of intermediates.
D. * Ensuring the enzyme is properly regulated.
E. A and C
66. Which of the following are properties of a cosubstrate?
A. * They are covalently attached to the active site of the enzyme.
B. Once they have been involved in an enzymatic reaction require a separate
unrelated enzymatic reaction to be converted to their original state.
C. They remain unchanged over the course of a reaction.
D. B and c
E. All of the above.
67. Which of the following coenzymes forms a Schiff’s base during catalysis?
A. NADH
B. Thiamin pyrophosphate
C. Lipoamide
D. * Pyridoxal phosphate
E. Coenzyme A
68. Which of the following cofactors is able to bind CO2 and transfer it to an appropriate
acceptor molecule?
A. * Pyridoxal phosphate
B. Biotin
C. Thiamin pyrophophosphate
D. Lipoamide
E. NAD(P)H
69. Which of the following common drugs is not a specific enzyme inhibitor?
A. Methotrexate
B. Penicillin
C. * Sulfonilamide
D. Iodine
E. Viagra
70. Which of the following factors contribute to the elevation of the ground state energy of a
substrate once it binds to the enzyme?
A. Less favorable entrophy values
B. Favorable charge-charge interactions
C. * Interactions between polar functional groups on the substrate surface and
hydrophobic amino acids in the enzyme’s substrate binding site.
D. A and b
E. A and c
71. Which of the following is characteristic of an enzyme catalyst?
A. It positions reactants in the correct orientation
B. It lowers the activation energy barrier
C. It binds the transition state tighter than the substrate
D. * Are affected by temperature
E. All of the above
72. Which of the following is true for a covalent catalysis based enzymatic mechanism.
A. A covalently modified enzyme intermediate is involved.
B. The enzyme undergoes a sequential reaction.
C. The enzyme undergoes a ping pong reaction.
D. a and b
E. * a and c
73. Which of the following kinetic parameters best describes how well suited a specific
compound functions as a substrate for a particular enzyme?
A. Km
B. Vmax
C. kcat
D. * kcat/Km
E. kg
74. Which of the following reversible inhibitors alter an enzyme’s function by increasing the
Vmax of the enzyme?
A. Competitive inhibitor
B. Non-competitive inhibitor
C. Uncompetitive inhibitor
D. * None of the above
E. Over-competitive inhibitor
75. Which of the following statements about reaction rate is NOT true?
A. Reaction rate is the speed at which the reaction proceeds toward equilibrium.
B. Reaction rate is governed by the energy barrier between reactions and products
C. * Enzymes can accelerate the rate of a reaction.
D. Reaction rates are not sensitive to temperature.
E. None of these.
76. Which property is common for enzymes and inorganic catalysts?
A. Specificity
B. Sensitiveness to the action of extraneous factors
C. * Catalysis only thermodynamics possible reactions
D. Dependence from рН and temperatures
E. High catalytic activity
77. Which statement is false about allosteric regulation?
A. * It is usually the mode of regulation for the last step in reaction pathways since
this step produces the final product.
B. Cellular response is faster with allosteric control than by controlling enzyme
concentration in the cell.
C. The regulation usually is important to the conservation of energy and materials in
cells.
D. Allosteric modulators bind non-covalently at sites other than the active site and
induce conformational changes in the enzyme.
E. B and C
78. Which statement is false about covalent modification?
A. It is reversible.
B. It is slightly slower than allosteric regulation.
C. * It usually uses the same enzyme for activation and inactivation.
D. All of the above
E. A and B
79. Which statement is false about regulatory enzymes that are controlled allosterically?
A. * They are always less active when a modulator is bound to them.
B. They are often larger than other enzymes.
C. They have more than one binding site.
D. They often catalyze the first step in a reaction pathway.
E. They have more than two binding site.
80. Why does heating interfere with the activity of an enzyme?
A. It kills the enzyme.
B. It changes the enzyme’s shape.
C. It decreases the energy of substrate molecules.
D. * It causes the enzyme to break up.
E. It decreases the chance that the enzyme will meet a substrate molecule.
81. Zymogens are inactive enzyme precursors which are made active by
A. A change in structure
B. Selective proteolysis
C. Secretion to new types of cells
D. a and b
E. * a, b and c
82. Which element is present in maltase, but not in maltose?
A. Carbon
B. Hydrogen
C. Oxygen
D. * Nitrogen
E. None of the above
83. _________ is the coenzyme involved in decarboxylation reactions.
A. Tetrahydrofolate.
B. NADH
C. Biotin
D. Thiamin pyrophosphate.
E. * Pyridoxol phosphate.
84. A certain enzyme will hydrolyze egg white but not starch. Which statement best explains
this observation?
A. Starch molecules are too large to be hydrolyzed.
B. * Enzyme molecules are specific in their actions.
C. Egg white acts as a coenzyme for hydrolysis.
D. Starch is composed of amino acids.
E. Egg white acts as a inhibitor for hydrolysis.
85. A coenzyme is
A. An ionic cofactor that interacts with an enzyme to allow it to work.
B. A protein cofactor that interacts with an enzyme to allow it to work.
C. * A nonprotein organic cofactor that interacts with an enzyme to allow it to work.
D. An ionic cofactor that interacts with an enzyme to inhibit it.
E. A protein cofactor that interacts with an enzyme to inhibit it.
86. A competitive inhibitor binds to
A. Substrate
B. * Active site
C. Allosteric site
D. Enzyme-substrate complex
E. Coenxyme
87. A competitive inhibitor of an enzyme is usually:
A. A highly reactive compound.
B. A metal ion such as Hg2+ or Pb2+.
C. * Structurally similar to the substrate.
D. Water insoluble.
E. A poison.
88. A laboratory test allows assuming the presence of inflammatory process in a liver. The
increase of what enzyme in blood will confirm this?
A. LDH 1,2
B. * Carbamoil phosphate ornitin transferase
C. AsAT
D. Creatin phosphokinase
E. Aldolase
89. A newborn suffers convulsions after meal, touches. It is discovered that reason of disease
is a defect of pyridine dependent enzyme which forms GABA in a brain. Name this
enzyme.
A. * Glutamate decarboxylase
B. Amino transferase
C. Cistationin synthase
D. Kinurinase
E. Ribonuclease
90. A phenylketonuria appears as a result of innate absence of enzyme:
A. Tirosin oxidase
B. * Phenylalanin-4-hydroxylase
C. Oxidase of gomogentisic acid
D. Amino oxidase
E. Xantine oxidase
91. A reversible inhibitor that can bind to either E alone or the ES complex is referred to as a
_____.
A. Competitive inhibitor.
B. * Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. Irreversible inhibitor
92. A reversible inhibitor that only binds to the ES complex is referred to as a _____.
A. Competitive inhibitor
B. Non-competitive inhibitor
C. Uncompetitive inhibitor
D. Suicide inhibitor
E. * Irreversible inhibitor
93. A substance that is Not a coenzyme is
A. * ATP
B. NAD+
C. NADPH
D. FAD
E. Pyrydoxal phosphate
94. Abzymes are
A. Immuno globulins
B. Isozymes
C. * Allosteric enzymes
D. Catalytic antibodies
E. Vitamins
95. According to the international classification there are six classes of enzymes in such
order:
A. Oxidoreductases, hydrolyses, ligases, lyases, transferases, isomerases.
B. Transferases, hydrolyses, oxidoreductase, isomerases, lyases, ligases.
C. Hydrolyses, oxidoreductase, transferases, lyases, isomerases, ligases.
D. Oxidoreductase, transferases, hydrolyses, isomerases, ligases, lyases.
E. * Oxidoreductase, transferases, hydrolyses, lyases, isomerases, ligases.
96. Active trypsin formation by the action of enteropeptidase can be viewed as the master
activation step because
A. It occurs first
B. It can activate its own zymogen
C. * Trypsin activates other pancreatic zymogens
D. A and B
E. A, B and C
97. Acyl-group-transfer reactions often involve which coenzyme?
A. * Coenzyme A
B. NAD+
C. Cytochrome c
D. All of the above
E. None of the above
98. Aldolase is classified as a(n)
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. * Lyase
E. Isomerase
99. Allosteric centers serve as:
A. * The place of influence on the enzyme different regulator factors
B. The place of enzyme and substrate relation
C. Catalytic area
D. Contact area
E. All of the above
100.
Allosteric enzymes _____________.
A. Usually have quaternary structure.
B. Do not behave according to Michaelis-Menten kinetics.
C. * Bind allosteric modulators at sites not associated with substrate binding.
D. Often have separate catalytic and regulator domains.
E. All of the above.
101.
Among the below named enzymes a metalloprotein is following:
A. * Carboanhydrase
B. Lactate dehydrogenase
C. Pepsin
D. Phosphatase
E. Amylase
102.
Among the enzymes of antioxide defense of an organism directly decomposes the
toxic hydrogen peroxide:
A. * Catalase
B. Superoxyde dismutase
C. Glutation peroxidase
D. Glutation reductase
E. Xantine oxidase.
103.
An enzyme is generally named by adding ____ to the end of the name of the
_____.
A. "-ose". cell in which it is found
B. "-ase". cell in which it is found
C. "-ose". substrate
D. * "-ase". substrate
E. "-ase". coenzyme
104.
An enzyme that catalyzes conversions of L-sugars to D-sugars is called an
A. Lyase
B. Hydrolase
C. Synthetase
D. Synthase
E. * Isomerase
105.
An enzyme that hydrolyzes protein will not act upon starch. This fact is an
indication that enzymes are
A. Hydrolytic
B. * Specific
C. Catalytic
D. Synthetic
E. Universal
106.
An increase of acetaldehyde in blood is causes disgust of an alcohol. What
preparation - the inhibitor of aldehyde dehydrogenase is used in medical practice for the
prophylaxis of alcoholism?
A. Ethanol.
B. * Teturam.
C. Trasilol
D. Aldehyde.
E. Methanol.
107.
An inhibitor binds to a site other than the active site of the enzyme. Which
statement below correlates with this observation?
A. It must be a competitive inhibitor.
B. The inhibition must be irreversible.
C. * It could be noncompetitive or uncompetitive inhibition.
D. It could be irreversible, competitive, noncompetitive or uncompetitive. The data
do not relate to the type of inhibition.
E. None of above
108.
An inhibitor that changes the overall shape and chemistry of an enzyme is known
as a(n)
A.
B.
C.
D.
E.
* allosteric inhibitor
competitive inhibitor
steric inhibitor
noncompetitive inhibitor
None of the above.
109.
An ion commonly found in metalloenzymes and which can undergo reversible
oxidation and reduction is
A. Ca++
B. Mg++
C. S=
D. * Fe++
E. All of the above
110.
An uncompetitive inhibitor of an enzyme catalyzed reaction
A. * Binds to the Michaelis complex (ES).
B. Decreases Vmax.
C. Is without effect at saturating substrate concentration.
D. Can actually increase reaction velocity in rare cases.
E. The first and second choices are both correct.
111.
An update of Fischer's lock and key theory of enzyme specificity view the
_______ as the lock and _______ as the key.
A. * Enzyme; substrate
B. Substrate; enzyme
C. Enzyme; transition state
D. Transition state; enzyme
E. Substrate; transition state
112.
At 25 C. the optimum reaction rate of a certain enzyme occurs at a pH of 7. A
greater reaction rate could probably be attained by
A. * Increasing the temperature to 35 C and keeping the pH at 7
B. Increasing both the temperature and the pH
C. Decreasing the pH and increasing the temperature
D. Increasing the pH and keeping the temperature at 25 C.
E. All of the above
113.
At a blood test was set that activity of catalase is 5 units. It is a symptom of:
A. Hypoxia
B. Acidosis
C. * Anemia
D. Starvations
E. Diabetes mellitus
114.
At about 0 C., most enzymes are
A. * Inactive
B. Active
C. Destroyed
D. Replicated
E. Denaturated
115.
At hepatitis, heart attack in blood of patients activity of alanine- and aspartate
amino transferases sharply grow. What reasons of activation of these enzymes in blood?
A. An increase of intensity of disintegration of amino acid in tissues
B. Activation of amino acids synthesis in tissues
C. Activation of enzymes with hormones
D. * Damage of cells membranes and output of enzymes in blood
E. Lack of pyridoxine
116.
At high temperatures, the rate of enzyme action decreases because the increased
heat
A. Changes the pH of the system
B. * Alters the active site of the enzyme
C. Neutralizes the acids and bases in the system
D. Increases the concentration of the enzyme
117.
At parodontitis the secretion of kallikrein is increased. Choose, what strengtheners
of inflammatory reaction appear in an oral cavity as result the of this enzyme action?
A. Trasilol
B. * Kinins
C. Secretory immunoproteins
D. Lysozyme
E. Factor of nerves growth
118.
At the heart attack in blood of a patient were found out increase of enzymes
activity. Choose these enzymes:
A. * Creatin kinase, AsAT and LDH1,2
B. Mono amino oxidase
C. Cytochrome oxidase, AlAT
D. Carbo anhydrase
E. Lactate dehydrogenase
119.
Ca++ or Mg++ are most likely to be part of ___________, while Zn++ or Fe++
are present in _______________.
A. * Metal-activated enzymes; metalloenzymes
B. Metalloenzymes; metal-activated enzymes
C. Cofactors; coenzymes
D. Coenzymes; cofactors
E. Apoenzymes; holoenzymes
120.
Catalase is found in all cells and protects them from a dangerous waste chemical
by breaking it down into water and oxygen. What is this waste chemical?
A. * Hydrogen Peroxide
B. Nitrogen Dioxide
C. Lactic Acid
D. Carbon Monoxide
E. Urea
121.
Choose the enzyme which includes zinc?
A. * Alcohol dehydrogenase
B. Cytochromoxidase
C. Xantine oksidase
D. Pyruvate dehydrogenase
E. Lactate dehydrogenase
122.
Determination of amylase in blood can be diagnostic criteria for:
A. Nephritis
B. Glossitis
C. * Acute pancreatitis
D. Hepatitis
E. Anemia
123.
During a gastric secretion proteolytic enzymes are secreted as proenzymes. What
enzyme is activated with hydrochloric acid:
A. * Pepsinogen
B. Trypsinogen
C. Amylase
D. Lipase
E. Chymotrypsinogen
124.
Enzymes
A. Enhance reaction rate
B. Are affected by pH
C. Act on specific substrates
D. Are affected by temperature
E. * All of the above
125.
Enzymes catalyze transfer of structural fragments from one substrate to other with
formation of two products. Name the class of this enzyme.
A. * Transferase
B. Isomerase
C. Oxidoreductase
D. Ligase
E. Hydrolase
126.
Enzymes fast up the velocity of a biochemical reaction by
A. Increasing activation energy
B. Decreasing kinetic energy
C. Removing the functional group
D. * Decreasing activation energy
E. All of the above
127.
Enzymes influence chemical reactions in living systems by
A. Providing the substrate required for the reaction to occur
B. * Affecting the rate at which reactions occur
C. Absorbing water released when polymers are formed
D. Combining with excess hydrogen to form gaseous wastes
E. Increasing activation energy
128.
Enzymes of which class are responsible for transfer of structural fragment from
one substrate to other with formation of two products?
A. Oxidoreductases
B. Isomerases
C. * Transferases
D. Ligases
E. Hydrolases
129.
Enzymes that are activated by proteolytic cleavage are referred to as __________.
A. Covalently modified enzymes
B. Enzyme complexes
C. * Zymogens
D. Polymerized
E. Free radicals
130.
For a diet therapy at indigestion of milk for children used milk with diminish
maintenance of lactose with fermentative way. What enzyme is used for this aim?
A. * beta-galactosidase
B. beta-glycosidase
C. alpha- glycosidase
D. alpha-amilase
E. beta- amilase
131.
For diminishing of a patient’s depression used preparation, which inhibits
enzyme, catalyzing decomposition of biogenic amines. Name this enzyme:
A. * MAO (mono amino oxidase)
B. LDH (lactate dehydrogenase)
C. CPK (creatin phosphokinase )
D. ASAT (aspartate amino transferase)
E. ALAT (alanine amino transferase)
132.
For dissolving of scars, compressions, hematomas, the easier transport of
medications in tissues such enzyme is used:
A. Trypsin
B. Ribonuclease
C. * Hyaluronidase
D. Plasmin
E. Pepsin
133.
For prevention of intestine atony the competitive inhibitor of acetylcholine
esterase is recommended for a patient. Choose it:
A. * Prozerin
B. Aspirin
C. Zarin
D. Indometocin
E. Allopurinol
134.
For treatment of viral infections it is used such enzyme preparation:
A. Plasmin
B. Collagenase
C. Lizocym
D. Hyaluronidase
E. * DNA-ase, RNA-ase.
135.
From the human blood serum selected five isoenzyme forms which catalyze the
same reaction.Choose this enzyme:
A. Glutathione reductase
B. Ceruloplasmin
C. * Lactate dehydrogenase
D. Glucose-6-phosphate dehydrogenase
E. Superoxide dismutase
136.
Glucose + ATP > Glucose -6-phosphate + ADP. This reaction is catalysed by
which of the following enzyme classes
A. Oxidoreductase
B. * Transferase
C. Hydrolase
D. Lyase
E. Isomerases
137.
Glycoside hydrolases such as bacterial cellulase have been shown to differ in
mechanisms from that of lysozyme. They
A. Are alkaline catalysts
B. Form a boat form of the sugar
C. * Form a covalent sugar-enzyme intermediate
D. Do not distort the substrate
E. Have no active site side chain interactions
138.
How is nonprotein part of enzyme called?
A. Holoenzyme.
B. Apoenzyme.
C. * Cofactor.
D. Apoprotein.
E. None of the above
139.
How many active centers can have enzymes?
A. 1
B. 3
C. 2
D. * Depends on the amount of subunits of enzyme
E. 10
140.
How many classes of enzymes are there?
A. 4.
B. 5.
C. * 6.
D. 7.
E. 2
141.
In a multienzyme complex the process of directly transferring a product of one
reaction to the next active site without allowing it to enter the bulk solvent is termed
_______.
A. a ping-pong reaction
B. * metabolite channeling
C. the activity pathway
D. the sequential mode
E. All of the above
142.
In an organism was found the lack of copper. It will cause the decrease of such
enzyme activity:
A. Cytochrome b
B. Glucose oxidase
C. Catalase
D. * Cytochrome oxsidase
E. Glutation peroxidase
143.
In an organism was found the lack of iron. It will cause the decrease of such
enzyme activity:
A. Glutation peroxidase
B. Carboanhydrase
C. Carboxypeptidase
D. Ceruloplasmin
E. * Catalase
144.
In blood of patient found out the increase of activity of LDH 4,5, AlAT, carbamoil
ornitin transpherase. In which organ is it possible development of pathological process?
A. * In a liver (hepatitis is possible)
B. In a cardiac muscle (the heart attack of myocardium is possible)
C. In skeletal muscles
D. In kidneys
E. In connecting tissue
145.
In diagnostics of heart attack an important role belongs to the methods of
enzymodiagnostic. Determination of what enzyme level in blood of in the first 2-4 hours
after sharp pain is important for diagnostic?
A. * Creatin phosphokinase
B. Acetylcholine esterase
C. Lipoprotein lipase
D. Alanine amino transferase
E. Aldolase
146.
In enzyme controlled reactions, the role of certain vitamins such as niacin is to act
as
A. An enzyme
B. A substrate
C. * A coenzyme
D. A polypeptide
E. An allosteric centre
147.
In formation of temporal complex between an enzyme and substrate important
role belongs to chemical bonds, except:
A. Disulfide
B. Ion
C. * Peptid
D. Hydrogen bonds
E. Hydrophobic interaction
148.
In saliva there is an enzyme which has a strong bactericide action due to ability to
destroy 1-4 glycoside bonds of peptide-glycans of bacterial wall. Choose this enzyme:
A. Amylase
B. * Lizocim (muramidase)
C. Trypsin
D. Phosphatase
E. Ribonuclease
149.
In the human organism single-electron reduction of molecular oxygen superoxide,
hydroxyl radicals and hydrogen peroxide, which have high reactional ability appear
constantly. A hydrogen peroxide inactivated in an organism with:
A. Ceruloplasmin
B. * Catalase
C. Glutathione reductase
D. Glucose-6-phosphatedehydrogenase
E. Superoxide dismutase
150.
Induced fit studies by Koshland using the enzyme hexokinase showed that there
are enzyme forms
A. which react with the hydroxyl group of water
B. which react only with ATP and glucose present together
C. which are hydrophobic, excluding the competing hydroxyl group from water
D. * with and without glucose bound to each
E. that hydrolyze AT
151.
is known as _________ inhibition.
A. * Competitive
B. Uncompetitive
C. Uncompetitive
D. Feedback
E. Allosteric
152.
Isoenzymes are generally separated by
A. Ion exchange chromatography
B. Gel filtration chromatography
C. Paper chromatography
D. * Electrophoresis
E. Selective adsorbtion
153.
Izoenzymes differ between itself some physical and chemical properties, except:
A. Electrophoretic mobility
B. * Molecular activity
C. Stability
D. Present in different tissues
E. Different primary structure
154.
Km is _______.
A. The substrate concentration at ? Vmax.
B. = (k-1 + kcat)/k1
C. Related to an enzymes affinity for a specific substrate.
D. The Michaelis Constant
E. * All of the above
155.
Lactate + NAD+ ---> Pyruvate + NADH + H+
A. * Oxidoreductase
B. Transferase
C. Hydrolase
D. Lyase
E. Ligase
156.
Lactate dehydrogenase is a
A. Coenzyme
B. * Isoenzyme
C. Zymogen
D. Abzyme
E. Prostetic group
157.
Lipase, maltase, and protease are members of a group of compounds known as
A. Hormones
B. Carbohydrates
C. Lipids
D. * Enzymes
E. Coenzymes
158.
Lock and key theory was proposed by
A. Sumner
B. * Fischer
C. Sanger
D. Buchner
E. Michaelis
159.
Lyzocym is a antibacterial factor, muraminidase as a mechanism of action (splits
1-4 glycoside bonds of muramine). What class of enzymes does it belong to?
A. Transferases
B. Oxidoreductases
C. Lyases
D. Isomerases
E. * Hydrolases
160.
Mg2+ is used as a(n) _________ by metal activate enzymes that utilize negatively
charged substrates like ATP.
A. Metalloenzyme
B. * Activator ion
C. Prosthetic group
D. Co-substrate
E. Ingibitor ion
161.
NAD+, FAD, and FMN are all cofactors for:
A. * Oxidoreductases
B. Transferases
C. Hydrolases
D. Lyases
E. Ligases
162.
Name laboratory tests which should be conducted for the patients with suspicion
on a acute pancreatitis:
A. total blood test
B. Activity of LDH
C. Activity of AlAT
D. * Activity of amylase in urine and blood
E. A level of sugar in blood
163.
New antibiotics are synthesized with fermentative transformations of natural
antibiotics. What from the below named forms of enzymes are widely used in
pharmaceutical industry?
A. * Immobilized enzymes
B. Native enzymes
C. Denaturized enzymes
D. Complex of enzyme with a coenzyme
E. Complex of enzyme with an activator
164.
Noncompetitive inhibitor binds with
A. Active site
B. Allosteric site
C. Enzyme substrate complex
D. * Substrate
E. Product of reaction
165.
One of major enzymes of saliva, providing death of bacteria is:
A. * Lysozyme
B. LDH
C. Phosphatase
D. AsAT
E. AlAT
166.
Oxidases, peroxidases, oxygenases or reductases are all
A. Lyases
B. Synthases
C. Synthetases
D. * Oxidoreductases
E. Hydrolases
167.
Phenylketonuria of newborn may be diagnosed after a reaction of urine with:
A. * FeCI3
B. CuSO4
C. NaCl
D. Fe+
E. Na3PO4
168.
Prosthetic group of cytochrome is:
A. FAD
B. Ubiqinon
C. Biotin
D. * Iron porphyryn complex
E. Cooper contain porphyryn complex
169.
Pyridoxal phosphate is involved in which type of reaction?
A. oxidation of pyruvate
B. * production of new amino acids by transamination
C. phosphate-transfer to produce ATP from ADP
D. the regeneration of methionine from homocysteine
E. none of the above
170.
Pyruvate + H+ ---> Acetaldhyde + Carbon dioxide
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. * Lyase
E. Ligase
171.
Pyruvate dehydrogenase complex is a multi-enzyme complex that catalyzes a
complicated multi-step reaction. The final reaction step is : FADH2 + NAD+ > FAD +
NADH + H+ The final step of this reaction falls into which enzyme class?
A. Transferases
B. Ligases
C. Lyases
D. * Oxidoreductases
E. Isomerases
172.
R-CH2OH + O2 > R-CHO + H2O2 which of the following types of enzymes
catalyzes this reaction
A. Dehydrogenae
B. Oxidase
C. * Peroxidase
D. Aldolase
E. Catalase
173.
Salivary amylase is an enzyme in humans that breaks down starch. The optimum
pH for this reaction is 6.7. The rate of this reaction would not be affected by
A. * Maintaining the pH of the reaction at 6.7
B. Substrate concentration
C. Enzyme concentration
D. Decreasing the temperature of the reaction by 5oC
E. Maintaining the pH of the reaction at 7.7
174.
Select the correct class of enzyme for this reaction. L-Glutamate + ATP + NH4+ --> L-glutamine + ADP + Pi
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. Lyase
E. * Ligase
175.
Select the correct class of enzyme for this reaction. L-aspartic acid + ґketoglutarate ---> oxaloacetic acid + L-Glutamate
A. Oxidoreductase
B. * Transferase
C. Hydrolase
D. Lyase
E. Ligase
176.
Select the correct class of enzyme for this reaction. Sucrose + H2O ---> Fructose
+ Glucose
A. Oxidoreductase
B. Transferase
C. * Hydrolase
D. Lyase
E. Ligase
177.
Select the correct class of enzyme for this reaction. L-Glutamate + ATP + NH4+ --> L-Glutamine + ADP + Pi
A. Oxidoreductase
B. Transferase
C. Hydrolase
D. Lyase
E. * Ligase
178.
Select the correct class of enzyme for this reaction. Polypeptide + H2O --->
Amino acids
A.
B.
C.
D.
E.
Oxidoreductase
Transferase
* Hydrolase
Lyase
Ligase
179.
The analysis demonstrated a 10 times increase of diastase activity. The danger of
autolysis of a patient’s pancreas caused with activating of enzyme:
A. Amylase
B. Pepsin
C. * Trypsin
D. Lipase
E. Nuclease
180.
?The biooxidation of xenobiotics takes place due to microsomal oxidation with
enzyme cytochrome P-450. What metal is the obligatory constituent of this enzyme?
A. * Fe
B. Zn
C. Na
D. Mg
E. K
181.
The class of enzymes that split peptide bonds or glycosidic bonds with water is
A. * hydrolases
B. lyases
C. transferases
D. isomerases
E. oxidoreductases
182.
The coenzyme biotin is involved in the transferring of the following groups
A. Amino group
B. * CO2
C. One carbon group
D. Acyl group
E. Amino acid residues
183.
The coenzyme present in transaminase
A. NAD+
B. TPP
C. Coenzyme A
D. * Pyridoxal phosphate
E. Biotin
184.
The defect of what enzyme results in disorders of decomposition of lactose at the
inherited genetic disorders of synthesis of enzymes in a human organism:
A. Amylase
B. Maltase
C. Sucrase
D. * Lactase
E. Peptidase
185.
The enzyme that catalyzes the reaction: glucose-6-phosphate + H2O > glucose +
phosphate can be assigned to which enzyme class?
A. oxidoreductases
B. isomerases
C. lyases
D. * hydrolases
E. transferases
186.
The enzyme which transfer groups between atoms within a molecule are
A.
B.
C.
D.
E.
Recemases
Mutases
* Transferases
Oxido-reductases
All of these
187.
The enzymes are inherent all physical and chemical properties of proteins, except:
A. High molecular mass
B. Breaking up to amino acid during a hydrolysis
C. Formation of colloid solutions
D. Antigen properties
E. * Stable to influence of high temperatures and salts of heavy metals
188.
The function of peroxidases is:
A. To split off hydrogen atoms or electrons from substrates and transfer them to any
acceptor except hydrogen peroxide and oxygen.
B. To split off hydrogen atoms or electrons from substrates and transfer them to
oxygen.
C. * To split off hydrogen atoms or electrons from substrates and transfer them to
hydrogen peroxide.
D. To decompose hydrogen peroxide.
E. To form hydrogen peroxide.
189.
The important enzyme of saliva is alkaline phosphatase. What class of enzymes
does it belong to?
A. * Hydrolases
B. Transferases
C. Oxidoreductases
D. Ligases
E. Lyases
190.
The inactive precursor of an active enzyme is called
A. * Zymogen
B. Ribozyme
C. Isozyme
D. Abzyme
E. Nucleozyme
191.
The inhibition of succinate dehydrogenase by malonate is an example for
A. * Competitive inhibition
B. Non competitive inhibition
C. Uncompetitive inhibition
D. Feedback or end product inhibition
E. None of these
192.
The inhibitors of proteolytic enzymes were recommended for a patient. For what
purpose necessary to apply such preparations:
A. * To avoid autolysis of pancreas.
B. To promote autolysis of pancreas.
C. To promote a hepatotoxity.
D. To reduce a hepatotoxity.
E. All answers are correct
193.
The ions of what metal contain porphirine coenzymes?
A. Na
B. * Fe
C. Zn
D. Mo
E. Mn
194.
The laboratory test allows diagnosing infarction of myocardium. The increase of
what enzyme in blood proves it?
A. LDH4,5
B. Arginase
C. Pyruvate dehydrogenase
D. * AsAT
E. ALAT
195.
The list of cofactors which are able in the process of fermentative reactions to
carry electrons and protons is below resulted, except of one cofactor which carries
chemical groups only. Choose it:
A. NAD
B. * Pyridoxal phosphate
C. FAD
D. Ubiqinon (coenzyme Q)
E. Hem coenzymes
196.
The mechanism of action of lysozyme include
A. Distortion of the substrate
B. Acid catalysis
C. Proximity effects
D. Formation of a half-chair sugar form
E. * All of the above
197.
The optimal pH for the enzyme pepsin is
A. * 1.0–2.0
B. 4.0–5.0
C. 5.2–?6.0
D. 5.8–6.2
198.
The patient with cyanide poisoning was delivered to clinic. What mast be
immediately used for the improvement of his state?
A. Glucose
B. Ascorbic acid
C. * Cytochromoxidase
D. Vitamin B1
E. Nicotine amide
199.
The protective function of saliva is predefined a few mechanisms, including
presence of enzyme, which has a bactericidal action, causes the lysis of polysaccharide
complex of membranes of staphylococcuss, streptococci. Name this enzyme.
A. Beta-glyucuronidase
B. Alfa-amylase
C. Oligo-1,6-glucosidase
D. Collagenase
E. * Lysozyme
200.
The term ligase refers to a class of enzymes that catalyzes_________.
A. Oxidation reduction reactions
B. Reactions involving the transfer of a functional group from one molecule to
another
C. Hydrolytic cleavages
D. * Reactions where two molecules are joined together
E. All of the above
201.
The uncompetitive inhibitor binds with
A. Active site
B. Allosteric site
C. * Enzyme substrate complex
D. Substrate
E. Product of reaction
202.
TPP is a/an _____________ of yeast pyruvate decarboxylase.
A. Cosubstrate
B. Intrinsic factor
C. Metalloenzyme
D. Prosthetic group
E. * Coenzyme
203.
Vitamins are essential to the survival of organisms because vitamins usually
function as
A. Substrates
B. Nucleic acids
C. * Coenzymes
D. Nucleotides
E. Enzymes
204.
What component is not included in the structure of holoenzymes?
A. Apoenzyme
B. Coenzyme
C. Cofactor
D. Prostetic group
E. * Izoenzyme
205.
What enzymes are located in the ribosomes?
A. * Ligases.
B. Oxido-reductases.
C. Transferases.
D. Isomerases.
E. Hydrolases.
206.
What enzymes catalyses the hydrolysis of triglycerides in the smal intestine?
A. * Lipases
B. Acetyl cholinesterases
C. Phospholipases
D. Transacylases
E. Monoglycerol lipases
207.
What is the area of an enzyme called where the chemical reactions occur?
A. The Cytoplasm
B. * The Active Site
C. The Catalyst
D. The Nucleus
E. A substrate
208.
What is the cause of primary enzymo-pathologies?
A. Liver diseases.
B. * Genetic disorders.
C. Trauma.
D. Ischemia.
E. All of these
209.
What is the chemical nature of enzymes?
A. Carbohydrates.
B. Lipids.
C. * Proteins.
D. Nucleic acids.
E. Fatty acids
210.
What kind of reaction do hydrolases catalyze?
A. * This group of enzymes catalyses hydrolytic cleavage reactions (such as the
formation of glucose from maltose by the action of the enzyme maltase).
B. These enzymes are involved in electron transfer oxidation/reduction reactions,
such as those in photosynthesis and cellular respiration.
C. These enzymes are involved in functional groups transfer
D. This group of enzymes catalyses none-hydrolytic cleavage reactions.
E. None of the above
211.
What kind of reactions is catalized by hydrolases?
A. * Hydrolytic cleavage of substrates.
B. Oxidation-reduction reactions.
C. Addition to double bonds.
D. Formation of bonds with ATP cleavage.
E. Synthesis of compounds
212.
What of the following statements are not true for the isoenzymes?
A. They differ in amino acid composition.
B. * They catalyze different reactions.
C. They differ in physical properties.
D. They are coded by different genes.
E. They active in different organs
213.
What pathology is developed in the absence of phenylalanine 4-monooxygenase?
A. * Phenylketonuria.
B. Alkaptonuria
C. Galactosemia.
D. Hyperglycemia.
E. Achilia
214.
What reactions would oxidoreductases is involved in?
A. This group of enzymes catalyses hydrolytic cleavage reactions (such as the
formation of glucose from maltose by the action of the enzyme maltase).
B. * These enzymes are involved in electron transfer oxidation/reduction reactions,
such as those in photosynthesis and cellular respiration.
C. These enzymes are involved in functional groups transfer
D. This group of enzymes catalyses none-hydrolytic cleavage reactions.
E. None of the above
215.
What structure of proteins molecule is responsible for formation of active centre
and for it catalytic action?
A. Primary
B. * Tertiary
C. Secondary
D. Quaternary
E. None from above
216.
Where are the hydrolases located in the cell?
A. In mitochondria
B. In nucleus.
C. In cytoplasm
D. * In lysosoms
E. In complex Golgi
217.
Which chemical is classified as an enzyme?
A. Galactose
B. Lipid
C. * Protease
D. Manganese dioxide
E. Sucrose
218.
Which cofactor has the following properties: a) forms Schiff base, b) its precursor
is absorb dietarily as Vitamin B6, c) is required in a number of reactions in aminoacid
metabolism.
A. Thiamin pyrophosphate
B. Biotin
C. Lipoamide
D. * Pyridoxal phosphate
E. Nicotinamid
219.
Which factor does not alter the rate of hydrolysis of maltose?
A. Temperature of the environment of the reaction
B. A pH of the environment of the reaction
C. Number of enzyme molecules present
D. * Size of the substrate molecule
E. None of the above
220.
Which group of organic compounds includes the enzymes?
A. * Proteins
B. Starches
C. Carbohydrates
D. Lipids
E. Nucleic acids
221.
Which of the following coenzymes functions in acyl transfer reactions?
A. NADPH
B. * Coenzyme A
C. Biotin
D. A and b
E. B and c
222.
Which of the following enzymes would digest a fat?
A. Sucrase
B. Fatase
C. Protease
D. * Lipase
E. None of the above
223.
Which property is common for enzymes and inorganic catalysts?
A. Specificity
B. Sensitiveness to the action of external factors
C. * Catalysis only thermodynamically possible reactions
D. Dependence from рН and temperature
E. High catalytic activity
224.
Which statement describes the currently accepted theory of how an enzyme and
its substrate fit together?
A. As the product is released, the enzyme breaks down.
B. The enzyme is like a key that fits into the substrate, which is like a lock.
C. The active site is permanently changed by its interaction with the substrate.
D. * As the substrate binds to the enzyme, the shape of the enzyme site changes to
accommodate the reaction.
E. All of the above
225.
Which statement is false about allosteric regulation?
A. * It is usually the mode of regulation for the last step in reaction pathways since
this step produces the final product.
B. Cellular response is faster with allosteric control than by controlling enzyme
concentration in the cell.
C. The regulation usually is important to the conservation of energy and materials in
cells.
D. Allosteric modulators bind non-covalently at sites other than the active site and
induce conformational changes in the enzyme.
E. B and C
226.
Which statement is false about regulatory enzymes that are controlled
allosterically?
A. * They are always less active when a modulator is bound to them.
B. They are often larger than other enzymes.
C. They have more than one binding site.
D. They often catalyze the first step in a reaction pathway.
E. They have more than two binding site.
227.
Which statement regarding enzyme function is true?
A. Higher temperatures allow greater contact between enzymes and substrates;
therefore, the higher the temperature the better the enzyme will function.
B. Enzymes cannot function at a pH lower than 6.
C. Most coenzymes are inorganic substances such as ions of iron or potassium.
D. Excessive salt ions can cause an enzyme to denature.
E. * All of the above.
228.
Which type of specificity of enzymes does not exist?
A. Relative
B. Absolute
C. * Conformation
D. None of above
E. Stereospecificity
229.
Which vitamins does not appear as coenzymes?
A. B1
B. B2
C. B5
D. * С
E. B12
230.
Wich enzymes do not include porphyrine coenzymes?
A. Cytochrome b, с
B. Catalase
C. Peroxidase
D. * Phosphatase
E. Cytochrome а1, а
231.
With ageing in cartilaginous decreases intensity of proteoglycans formation that
leads to diminishing of degree of their hydratation and loss of tissues turgor. Activity of
what enzymes of lysosomes does increase?
A. Deaminase, decarboxylase
B. Isomerase, dehydrogenases
C. Protease, lipase
D. Oxidoreductases, phosphstase
E. * Cathepsins, glycosidase
232.
With urine of newborn was done a reaction with FeCI3 and a positive reaction
(dark color) got. What disease is possible?
A. Galactosemia
B. Tirosinosis
C. * Phenylketonuria
D. Alkaptonuria
E. Aminoaciduria.
233.
Zinc is present in which of the following enzymes
A. Cytochrome oxidase
B. Arginase
C. Hexokinase
D. * Alcoholdehydrogenase
E. Catalase
234.
Zymogens are inactive enzyme precursors which are made active by
A. A change in structure
B. Selective proteolysis
C. Secretion to new types of cells
D. a and b
E. * a, b and c
235.
? An amphibolic pathway among the following is
A. HMP shunt
B. Glycolysis
C. * Citirc acid cycle
D. Gluconeogenesis
E. A and B
236.
ATP is an energy-rich molecule because:
A. it contains adenine;
B. it contains monosaccharide ribose that can be oxidized with energy formation
C. * its triphosphate unit contains two phosphoanhydride bonds
D. it forms complex with Mg2+ or Mn2+
E. all of the above
237.
Isocitrate dehydrogenase can use __________ as a cofactor.
A. NAD+ only
B. NADP+ only
C. * NAD+ or NADP+
D. FMN and FAD
E. TPP only
238.
Isocitrate dehydrogenases is
A. * Aerobic dehydrogenase
B. Anaerobic dehydrogenase
C. Hydroperoxidase
D. Oxygenase
E. Ligase
239.
Name the common product of the second stage of catabolism of carbonhydratess,
lipids and amino acids.
A. * Acetyl-CoA.
B. Pyruvate
C. Citric acid.
D. Acyl-CoA.
E. ATP
240.
Pyruvate dehydrogenase complex and ?-ketoglutarate dehydrogenase complex
require the following for their oxidative decarboxylation:
A. COASH and Lipoic acid
B. NAD+ and FAD
C. COASH and TPP
D. * COASH, TPP,NAD+,FAD, Lipoate
E. A and C
241.
Pyruvate dehydrogenase is a/an
A. Isomerase
B.
C.
D.
E.
Lyase
Ligase
* Oxido reductase
Transferase
242.
The number of molecules of ATP produced by the total oxidation of acetyl CoA
in TCA cycle is
A. 6
B. 8
C. 10
D. * 12
E. 15
243.
Which of the following is located in the mitochondria?
A. Cytochrome oxidase
B. Succinate dehydrogenase
C. Dihydrolipoyl dehydrogenase
D. * All of these
E. None of these
244.
Which of the following metabolite integrates glucose and fatty acid metabolism?
A. * Acetyl CoA
B. Pyruvate
C. Citrate
D. Lactate
E. None of the above
245.
_____ is another term for biosynthesis.
A. Catabolism
B. * Anabolism
C. . Metabolism
D. Catalyst
E. Oxidation
246.
A deficiency in thiamin causes the disease beriberi. Which might you expect to
have a higher than normal blood concentration in an individual with this condition?
A. isocitrate
B. * pyruvate
C. oxaloacetate
D. acetyl CoA
E. malate
247.
A patient was diagnosed with beri-beri disease. Activity of which enzyme is
inhibited in an organism of the patient?
A. Fumarase
B. Citrate synthase
C. Malate dehydrogenase
D. Succinate dehydrogenase
E. * Pyruvate dehydrogenase
248.
Among citric acid cycle enzymes, a flavoprotein is
A. Malate
B. Fumarase
C. * Succinate dehydrogenase
D. Isocitrate dehydrogenase
E. All of these
249.
Among the many molecules of high-energy phosphate compounds formed as a
result of the functioning of the citric acid cycle, one molecule is synthesized at the
substrate level. In which of the following reactions does this occur?
A.
B.
C.
D.
E.
Citrate C-ketoglutarate
* B-ketoglutarate --succinate
Succinate SSfumarate
Fumarate FFmalate
Malate MMoxaloacetate
250.
Anabolic pathways _______
A. Do not depend on enzymes.
B. * Consume energy to build up polymers from monomers.
C. Lead to the synthesis of catabolic compounds.
D. Release energy as they degrade polymers to monomers.
E. All of the above
251.
Anabolic reactions with the formation of new bonds and utilization of ATP energy
are catalyzed by:
A. oxidoreductases;
B. hydrolases;
C. isomerases;
D. * ligases.
E. transferases
252.
As resalt of hypovitaminosis a 55 years old man has sympthoms of oxidative
decarboxilation of pyruvate inhibition. Oxidative decarboxilation of pyruvate results in
formation of molecules ATP:
A. 2 ATP
B. * 3 ATP
C. 15 ATP
D. 12 ATP
E. 38 ATP
253.
As resalt of hypovitaminosis a 55 years old woman has sympthoms of oxidative
decarboxilation of pyruvate inhibition. Aerobic oxidation of pyruvate to CO2 and H2O
results in formation of molecules ATP:
A. 38 ATP
B. 12 ATP
C. 3 ATP
D. * 15 ATP
E. 2 ATP
254.
As resalt of hypovitaminosis and low activity of enzymes a man has sympthoms
of oxidative decarboxilation of pyruvate inhibition. Cofactors of dehydrogenases are all,
except one:
A. NAD+
B. * c-AMP
C. NADP+
D. FMN
E. FAD
255.
Before pyruvic acid enters the TCA cycle it must be converted to
A. * Acetyl CoA
B. Lactate
C. ?-ketoglutarate
D. Citrate
E. Malate
256.
Before pyruvic acid enters the TCA cycle it must be converted to
A. * Acetyl CoA
B. Lactate
C. ?-ketoglutarate
D. Citrate
E. Malate
257.
Compounds like succinate, fumarate and а-ketoglutarate have a catalytic effect on
the consumption of oxygen in a cell suspension. The rate of oxygen consumption is far
more than that required for their own oxidation. This is evidence that ________.
A. they are intermediates in glycolysis
B. they act as enzymes to cause the oxidation of other compounds
C. * they are involved in a cyclic pathway
D. they must be cofactors for enzymes that are oxidoreductases
E. All of these
258.
Dehydrogenation of succinic acid to fumaric acid requires the following hydrogen
carrier:
A. NAD+
B. NADP+
C. * flavoprotein
D. Glutathione
E. FAD
259.
Dehydrogenation of succinic acid to fumaric acid requires the following hydrogen
carrier:
A. NAD+
B. NADP+
C. * Flavoprotein
D. Glutathione
E. Both A and C
260.
does this occur?
A. Citrate - C-ketoglutarate
B. * Succinil-CoA SSsuccinate
C. Succinate SSfumarate
D. Fumarate FFmalate
E. Malate MMoxaloacetate
261.
During wet beriberi, peripheral vessels dilate and heart muscles loose their
contractility. Some people think this is a result of a failure of the TCA cycle. Evidence
for this is an increase in the
A. Rate of production of succinate
B. Rate of production of NADH
C. * Concentration of alpha-ketoglutarate and pyruvate
D. Production of ATP
E. Production of FADH2
262.
During wet beriberi, peripheral vessels dilate and heart muscles loose their
contractility. Some people think this is a result of a failure of the TCA cycle. Evidence
for this is an increase in the
A. Rate of production of succinate
B. Rate of production of NADH
C. * Concentration of alpha-ketoglutarate and pyruvate
D. Production of ATP
E. Production of FADH2
263.
For the two years old boy of a energy metabolism is inhibited due to processes of
oxidation and ATP formation. Maintenance of metabolites of Krebs cycle in blood is
decreased. What product of metabolism is the competitive inhibitor of Succinate
dehydrogenase?
A. * Malonate
B. Malate
C. Aspartate
D. Glutamate
E. Citrate
264.
For treatment of many diseases cocarboxylase (thiaminpyrophosphate) is used for
providing of energy for cells. Choose what metabolic process is activated in this case?
A. * oxidative decarboxilation of pyruvate
B. deamination of glutamate
C. decarboxilation of histidin
D. transamination of aspartate
E. substrate level phosphorylation
265.
How many ATP molecules can be derived from each molecule of acetyl CoA that
enters the Krebs’ Cycle?
A. 6
B. * 12
C. 18
D. 38
E. 39
266.
How many molecules of ATP are formed during the full oxidation of 1 molecule
of acetyl CoA?
A. * 12.
B. 24.
C. 36.
D. 38.
E. 15.
267.
How many molecules of NADH is formed during the conversion of ONE
molecule of pyruvate to acetyl CoA?
A. * 1;
B. 2;
C. 3;
D. NADH2 is not formed, 1 molecule of NADPH is produced.
E. 4
268.
How many substrate level phosphorylation reactions are in tricarboxylic acid
cycle?
A. * 1;
B. 2;
C. 3;
D. 5;
E. there are not substrate level phosphorylation reactions.
269.
Hyperproduction of insulin by pancreas of 35 years old patient caused activation
of TCA. The citric acid cycle oxidizes pyruvate and some of the pathway intermediates
are starting materials for many biosynthetic pathways. This means the citric acid cycle is
a/an ______________.
A. amplifying pathway
B. strictly catabolic pathway
C. anaerobic pathway
D. * amphibolic pathway
E. both A and D
270.
In blood and urine of a patient is increased value of pyruvic and ?-ketoglutaric
acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
271.
In blood and urine of a patient it was takes place increase value of pyruvic and
ketoglutaric acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
272.
In citric acid cycle, GDP is phosphorylated by
A. Succinate dehydrogenase
B. Aconitase
C. * Succinate thiokinase
D. Fumarse
E. ?-ketoglutarate dehydrogenase
273.
Luck of insulin caused inhibition of TCA in the organism of 35 years old patient.
For one turn of Krebs cycle ATP molecules are formed:
A. 38 ATP
B. * 12 ATP
C. 15 ATP
D. 1 ATP
E. 15 ATP
274.
Metabolism is defined as:
A. a sequence of reactions that has a specific purpose;
B. * the entire network of chemical reactions carried out by living cells;
C. degradation of macromolecules molecules to create smaller molecules and
energy;
D. synthesis of the molecules for cell maintenance, growth and reproduction.
E. none of the above
275.
Most CO2 produced during aerobic cellular respiration is released during
A. Oxidative phosphorylation
B. Lactate fermentation.
C. * The Kreb’s cycle
D. Electron transport
E. Glycolysis.
276.
NAD and NADP dependent dehydrogenases catalyze substrates by transferring
__________ to C-4 of NAD+ and NADP+.
A. An electron
B. Two electrons
C. An electron and a proton
D. * Two electrons and a proton
E. Two electrons and two protons
277.
NADH ____________ Krebs cycle and ATP _______________ it.
A. activates; activates;
B. activates; inhibits;
C. inhibits; activates;
D. * inhibits; inhibits;
E. none of the above.
278.
One of the affects of thiamin deficiency in alcoholics is that muscles do not
contract adequately. An explanation for this is that:
A. * Alpha-ketoglutarate in the TCA cycle requires thiamin
B. Glucose-6-phosphate dehydrogenase has an absolute requirement for thiamin
C. Pyruvate carboxylase has a requirement for thiamin
D. Thiamin is an intermediate in the electron transport chain
E. Myosin ATPase has an absolute requirement for thiamin
279.
Organism suffers from hypovitaminosis of B5. How will it change the function of
oxidoreductases?
A. It will inhibit synthesis and functions of cytochroms
B. It will inhibit synthesis and functions of FMN and FAD – dependent
dehydrogenases
C. It causes improper synthesis and functions of TPP, which is the coenzyme of
pyruvate dehydrogenase.
D. It causes inhibition of synthesis and functions of aminotransferases.
E. * It causes inhibition of synthesis and functions of NAD and NADP – dependent
oxidoreductases (dehydrogenases)
280.
Out of 24 mols of ATP formed in TCA cycle, 2 molecules of ATP can be formed
at “substrate level” by which of the following reaction ?
A. Citric acid>?Isocitric acid
B. Isocitrate>?Oxaloacetate
C. Succinic acid>?Fumarate
D. * Succinyl CoA>?Succinic acid
E. A and B
281.
Patient suffers from severe hypovitaminosis, low activity of dehydrogenases.
Cofactors of dehydrogenases are all, except one:
A. NAD+
B. * c-AMP
C. NADP+
D. FMN
E. FAD
282.
Patient with hypofunction of thyrod gland suffers from loose ob body weight as
result of catabolism activation. Catabolism is characterized by _______________ of three
major routs toward a final common pathway.
A. divergence;
B. * convergence;
C. splitting;
D. none of the above.
E. all of the above.
283.
Patient with hypofunction of thyrod gland suffers from general weakness due to
inhibition of metabolism. Metabolism is defined as:
A. a sequence of reactions that has a specific purpose;
B. * the entire network of chemical reactions carried out by living cells;
C. degradation of macromolecules molecules to create smaller molecules and
energy;
D. synthesis of the molecules for cell maintenance, growth and reproduction.
E. none of the above
284.
Pyruvate passes through the outer mitochondrial membrane by _____________.
A. * porin proteins
B. passive transport
C. pyruvate translocase
D. simple diffusion through the lipid bilayer
285.
Pyruvate translocase is a/an _________________ protein that transports
____________.
A. antiport; pyruvate and H+ in opposite directions
B. uniport; only pyruvate
C. * symport; pyruvate and H+ in the same direction
D. antiport; pyruvate and CO2 in opposite directions
E. symport; pyruvate and CO2 in the same direction
286.
Rate of the TCA reactions in an organism of 55 years old patient with diabetes
mellitus is decreased. The oxidation of acetyl CoA in citric acid cycle to CO2 and water
is the _________ stage of catabolism and this is ___________ stage.
A. first, specific;
B. second, nonspecific;
C. third, specific;
D. * third, nonspecific.
E. second, specific.
287.
Reduction of which one of the following substrates leads to a reducing equivalent
in a step of the citric acid cycle?
A. Succinyl CoA
B. * Malate
C. Fumarate
D. Oxaloacetate
E. Citrate
288.
Substrate level phosphorylation in TCA cycle is in step:
A. Isocitrate dehydrogenase
B. Malate dehydrogenase
C. Aconitase
D. * Succinate thiokinase
E. None of these
289.
Substrate level phosphorylation in TCA cycle is in step:
A. Isocitrate dehydrogenase
B. Malate dehydrogenase
C. Aconitase
D. * Succinate thiokinase
E. ?-ketoglutarate dehydrogenase
290.
The accumulation of pyruvate in blood, decrease of activity of transketolase of red
blood cells takes place in organism of a 46 years old chronic alcoholic. Insufficiency of
coenzyme form of which vitamin causes such changes?
A. * Thiamine diphosphate
B. Carboxybiotin
C. Metylcobalamin
D. Phosphopyridoxal
E. Tetrahydrofolate
291.
The coenzyme electron carriers produced in the Krebs cycle are
A. ATP and ADP
B. Pyruvate and acetyl CoA
C. * FADH2 and NADH
D. NAD and NADH
E. NADH and ATP
292.
The coenzyme not involved in the formation of acetyl-CoA from pyruvate is
A. TPP
B. * Biotin
C. NAD
D. FAD
E. Both A and B
293.
The conversion of pyruvate to acetyl CoA and CO2
A. Is reversible
B.
C.
D.
E.
* Involves the participation of lipoic acid
Depends on the coenzyme biotin
Occurs in the cytosol
All of the above
294.
The conversion of pyruvate to acetyl CoA and CO2
A. Is reversible
B. * Involves the participation of lipoic acid
C. Depends on the coenzyme biotin
D. Occurs in the cytosol
E. Both A and B
295.
The high toxicness of ammonia for the neurons of CNS is predetermined braking
of TCA and, as a result, decline of the tissue respiration, oxidative phosphorylation ,
ketonemia. Reason is a binding of ammonia to the following components of cycle:
A. * A - ketoglutarate
B. Isocitrate
C. Succinate
D. Fumarate
E. Oxaloacetate
296.
The number of ATP produced in the succinate dehydrogenase step is
A. 1
B. * 2
C. 3
D. 4
E. 5
297.
The number of ATP produced in the succinate dehydrogenase step is
A. 1
B. * 2
C. 3
D. 4
E. 5
298.
?The patient with cyanide poisoning was delivered to clinic. What mast be
immediately used for the improvement of his state?
A. Glucose
B. Ascorbic acid
C. * Cytochromoxidase
D. Vitamin B1
E. Nicotine amide
299.
The rate at which pyruvate from glycolysis is used by the TCA cycle to produce
energy is regulated by pyruvate dehydrogenase. During muscle contraction, this enzyme
is
A. Inhibited by increases in the calcium concentration.
B. Activated by increased in acetyl CoA
C. Activated by increases in NADH
D. * Activated by increases in ADP
E. Inhibited by increases in AMP
300.
Your patient is an alcoholic a buildup of a-ketoacids and symptoms of wet
beriberi. All of the following might be part of a scenario that would explain why
peripheral vessels dilate and cardiac muscles loose their contractility EXCEPT
A. Muscle needs ATP to contract
B. Most ATP is produced by oxidative phosphorylation
C. NADH and FADH2 are produced by the TCA cycle
D. The TCA cycle needs thiamine pyrophosphate to function
E. * A shortage of thiamine results in the inability to oxidize NADH
301.
_____ is another term for biosynthesis.
A. Catabolism
B. Anabolism
C. * Metabolism
D. Catalyst
E. Oxidation
302.
2,4-Dinitrophenol and oligomycin inhibit mitochondrial oxidative
phosphorylation. 2,4-Dinitrophenol is an uncoupling agent; oligomycin blocks the ATP
synthesis reaction itself. Therefore, 2,4-dinitrophenol will:
A. * Allow electron transfer in the presence of oligomycin.
B. Allow oxidative phosphorylation in the presence of oligomycin.
C. Block electron transfer in the presence of oligomycin.
D. Diminish O2 consumption in the presence of oligomycin
E. Do none of the above.
303.
A chemical reaction that has a positive DeltaG is correctly described as _______
A. Exothermic.
B. Exergonic.
C. * Endergonic.
D. Enthalpic.
E. Spontaneous.
304.
A chemical reaction with a positive Go' would be considered a/an
A. Exergonic reaction.
B. Energy generating reaction.
C. Catabolic reaction.
D. * Endergonic reaction
E. A and B
305.
A compound with a greater free energy of hydrolysis than ATP is
A. Glucose 1-phosphate
B. Any phosphoester
C. * Phosphoenolpyruvate
D. Acetyl CoA
E. All of the above
306.
A distinct set of metabolic reactions is called a reaction ________________.
A. Network
B. Cycle
C. * Pathway
D. Mechanism
E. A and B
307.
A molecule who’s function is to release energy quickly is a
A. Fatty acids
B. Nucleic acids
C. * Monosaccharides
D. Amino acids
E. Vitamins
308.
A process common to all living organisms, aerobic and anaerobic, is
A. * Glycolysis
B. Fermentation
C. The Krebs cycle
D. Electron transport chain reactions
E. Pyruvate oxidation
309.
A reduced compound is
A.
B.
C.
D.
E.
NAD
FAD
* NADH
ADP
ATP
310.
A third class of inhibitors - hydrogen cyanide, hydrogen sulfide, and carbon
monoxide block electron transport from:
A. Cytochrom c to CO2
B. * Cytochrome aa3 to oxygen
C. Cytochrom b to c
D. Cytochrom b to aa3
E. NADH to Fe-S proteins
311.
After adding of 1-2 drops of NADI-reagent on the boiled portion of muscles the
color doesn't appear - is the result of the:
A. Soulting-out of proteins
B. * Enzyme denaturation
C. Enzyme renaturation
D. Enzyme decarboxilation
E. Activation of enzymes
312.
All of the following processes produce ATP, except:
A. * Lactic acid formation
B. Oxidative phosphorilation
C. Glycolysis
D. The Krebs cycle
E. The electron transport chain
313.
All of the following statements about NAD+ are false except:
A. NAD+ has the appearance of a double nucleotide
B. * NAD+ is reduced to NADH by way of acceptance of a single electron and
proton
C. NAD+ catalyzes the reactions of glycolysis by acting as an enzyme
D. NAD+ provides the energy necessary for the non-spontaneous reactions of
glycolysis to occur
E. NAD+ has more chemical energy than does NADH
314.
Almost all of the oxygen (O2) one consumes in breathing is converted to:
A. Acetyl-CoA.
B. Carbon dioxide (CO2)
C. Carbon monoxide and then to carbon dioxide.
D. None of the above.
E. * Water.
315.
An electron transferred in a biological system is usually
A. Boosted to a higher light energy state
B. * Converted into other chemical compounds
C. Accompanied by a proton
D. Given off as radiant energy
E. Lost to the system as heat
316.
As energy is being reconverted through the many forms, it is continuously lost as
A. Electricity
B. Light
C. Sound
D. Heat
E. * Chemical energy
317.
At one time the uncoupler 2,4-dinitrophenol was used as a weight reducing drug.
Its side-effects, including death, resulted in its discontinued use. How could this drug
cause weight loss?
A. * The uncoupler allows the oxidation of fats from adipose tissue without the
production of ATP. This allows the oxidation to proceed continuously and uses up
the fats.
B. The uncoupler causes ATP to be produced at a much higher rate than normal and
this causes weight loss.
C. The uncoupler inhibits the transport of pyruvate into the matrix of the
mitochondria. Fats are then degraded to glycerol to subsequently to pyruvate to
provide the necessary energy. Thereby depleting fat stores.
D. The uncoupler is an allosteric activator of ATP synthase. This increases the rate
of translocation of H+ and the oxidation of fuels, including fats.
E. B and C only
318.
ATP can be used to activate a substrate by
A. Phosphorylation
B. Adding a nucleotidyl group
C. Producing inorganic phosphate
D. * Both a and b
E. A, b, and c
319.
ATP is the most commonly used source of energy rich compounds in cells
because
A. It complexes with Mg++
B. It has a higher free energy of hydrolysis
C. Its products of hydrolysis are more stable the ATP
D. * It is used more often than other nucleoside triphoshates
E. It engages in phosphoryl-group transfers
320.
ATP is thermodynamically suited as a carrier of phosphoryl groups in animal cells
because
A. It is stable under cell conditions
B. It is not hydrolyzed in cells without enzyme action
C. It is intermediate in group-transfer potential
D. It can be produced from phosphocreatine
E. * All of the above
321.
ATP synthase complexes can generate _______ATP(s) for each NADH that
enters electron transport.
A. * 1
B. 2
C. 3
D. 4
E. 8
322.
Carrier molecules in the cell membrane and metabolic energy are required for:
A. Osmosis
B. Facilitated diffusion
C. * Active transport
D. All the above
E. B & C only
323.
Cells store energy when _____.
A. * The third phosphate group breaks off from an ATP molecule
B. They break down sucrose to glucose and fructose
C. A third phosphate group is bonded to an ATP molecule
D. Ions are released into the bloodstream
E. None of the above
324.
Chemiosmotic generation of ATP is driven by
A. Phosphate transfer through the plasma membrane
B. Sodium, potassium pump
C. * A difference in H+ concentration on the two sides of the mitochondrial
membrane
D. Osmosis of macromolecules
E. Large quantities of ADP
325.
Consider the figure. How many ATP's are generated from glucose in the absence
of oxygen?
A. 2
B. 4
C. 34
D. 38
E. 12
326.
Consider the synthesis of a biopolymer in which the addition of successive
monomers occurs by the same kind of reaction(s). The synthesis of the polymer is a
________ pathway.
A. Linear
B. Cyclic
C. * Spiral
D. Branched
E. A and B
327.
Cytochrome P450 is a two-enzyme sequence in eucaryotes, containing both FAD
and FMN. The function of these coenzymes is
A. Reduce O2
B. React with foreign or natural substance indicated by RH
C. * Carry electrons from NADPH to oxygen
D. Provide a hydrophobic channel in the protein pocket
E. All of the above
328.
destabilizes the phosphoanhydride bonds in ATP.
A. The symbol ATP represents the molecule adenosine triphosphate.
B. In the presence of O2, the majority of ATP is synthesized by enzymes in
C. In the absence of O2, all ATP is synthesized in glycolysis.
D. * The electrostatic repulsion among the ATP phosphate groups
E. The phosphorylation of ADP is exergonic
329.
During oxidative phosphorylation, the proton motive force that is generated by
electron transport is used to:
A. Create a pore in the inner mitochondrial membrane
B. Generate the substrates (ADP and Pi) for the ATP synthase
C. * Induce a conformational change in the ATP synthase
D. Oxidize NADH to NAD+
E. Reduce O2 to H2O
330.
Each NAD molecule carryng hydrogen to the electron transport chain can produce
how mane moleculs of ATP?
A. 1
B. 2
C. * 3
D. 4
E. Cannot be determine
331.
Energy from sunlight is trapped by chlorophyll located in the _____.
A. Citric acid cycle
B.
C.
D.
E.
* Mitochondria
Electron transport chain
Thylakoid membranes
Synthesis of urea
332.
Energy is carried from catabolic to anabolic reactions in the form of
A. ADP
B. * High-energy ATP bonds
C. Coenzymes
D. Inorganic phosphate
E. Oxygen
333.
Energy is released from ATP when the bond is broken between _____.
A. * Two phosphate groups
B. Adenine and ribose
C. Ribose and a phosphate group
D. Adenine and a phosphate group
E. B and C only
334.
Energy requiring metabolic pathways that yield complex molecules from simpler
precursors are:
A. Amphibolic
B. * Anabolic
C. Autotrophic
D. Catabolic
E. Heterotrophic
335.
enough free energy to rephosphorylate:
A. 6 ATP
B. * 5 ATP
C. 4 ATP
D. 3 ATP
E. None of the above are correct
336.
Enzymes are biological catalysts that enhance the rate of a reaction by:
A. * Decreasing the activation energy
B. Decreasing the amount of free energy released
C. Increasing the activation energy
D. Increasing the amount of free energy released
E. Increasing the energy of the transition state
337.
Exergonic reactions
A. * Release potential energy
B. Consume energy
C. Form bonds
D. Occur only outside the cell
E. All of the above
338.
Fermentation can be described as a process
A. * That takes place only in the absence of oxygen
B. In which the recipient of hydrogen atoms is an organic molecule
C. In which water is not one of the by-products
D. In which the Krebs cycle and electron transfer through ETS do not occur
E. All of the above are true
339.
For normal mitochondria in the presence of an oxidizable substrate and an
uncoupler such as 2,4-dinitrophenol which do you expect?
A. Oxygen consumption even in the absence of ADP
B. A rise in temperature to dissipate energy that would otherwise have been used to
generate ATP
C. The flow of protons into the mitochondria matrix
D. * All of the above
E. None of the above
340.
How many ATP molecules are produced when FADH2 delivers electrons to the
electron transport system?
A. 1
B. * 2
C. 4
D. 36
E. 12
341.
How many ATP molecules can be derived from each molecule of acetyl CoA that
enters the Krebs’ Cycle?
A. 6
B. * 12
C. 18
D. 38
E. 39
342.
How many reactions of substrate-level phosphorylation are in an organism?
A. 2.
B. * 3.
C. 4.
D. 5.
E. 12
343.
If heat energy is absorbed by the system during a chemical reaction, the reaction is
said to be:
A. At equilibrium
B. Endergonic
C. * Endothermic
D. Exergonic
E. Exothermic
344.
If the free energy change ?G for a reaction is -46.11 kJ/mol, the reaction is:
A. At equilibrium
B. Endergonic
C. Endothermic
D. * Exergonic
E. Exothermic
345.
In a fermentation metabolism, the organism produces ATP by
A. Generation of a proton motive force by transfer of electrons to oxygen
B. Substrate level phosphorylation
C. Oxidizing NADH to form the proton motive force
D. More than one of the above
E. * A, B, C
346.
In a system where temperature is uniform, free energy is ___
A. * The energy available to do work.
B. The extra energy emitted by the system
C. The total energy of the system
D. Kinetic energy.
E. Equivalent to entropy.
347.
In an electron carrier system, the net energy change is determined by the
difference in reduction potentials between the
A. Primary electron donor and the terminal electron donor.
B. Primary electron acceptor and the terminal electron acceptor.
C. Primary electron acceptor and the terminal electron donor.
D. * Primary electron donor and the terminal electron acceptor.
E. Secondary electron acceptor and the terminal electron acceptor
348.
In an exothermic chemical reaction
A. The mass of the products is greater than the mass of the reactants
B. The mass of the products is less than the mass of the reactants
C. * Heat is released as the reaction proceeds
D. Heat is absorbed as the reaction proceeds
E. None of the above
349.
In cellular metabolism, ATP provides energy by:
A. Releasing heat upon hydrolysis
B. Acting as a catalyst in chemical reactions
C. Stealing electrons from glucose and it’s intermediates
D. * Releasing a terminal phosphate group
E. Oxidizing helper molecules
350.
In normal mitochondria, the rate of NADH consumption (oxidation) will:
A. Be increased in active muscle, decreased in inactive muscle.
B. Be very low if the ATP synthase is inhibited, but increase when an uncoupler is
added.
C. Decrease if mitochondrial ADP is depleted.
D. Decrease when cyanide is used to prevent electron transfer through the
cytochrome a + a3 complex.
E. * All of the above are true.
351.
In order for a reaction to proceed from left to right as written
A. ATP must be involved in the reaction
B. A common intermediate must be formed
C. * The overall free-energy changes must be negative
D. A phosphate group must be transferred
E. All of the above
352.
In order to move molecules in your kidneys, your body needs _____.
A. * Energy
B. Sunlight
C. Cold
D. Heat
E. Only C and D
353.
In oxidative respiration, energy is harvested from glucose molecules in a sequence
of four major pathways. Which of the following is not one of these four pathways?
A. Krebs cycle
B. Glycolysis
C. Electron transfer through the transport chain
D. * Beta oxidation
E. Pyruvate oxidation
354.
In respiration, the final electron acceptor in the electron transport chain is _____.
A. Oxygen
B. ATP
C. Hydrogen ions
D. * H2O
E. CO2
355.
In the absence of oxygen, eukaryotic cells are restricted to
A. Chemiosmotic phosphorylation
B. Cyclic photo phosphorylation
C. Noncyclic photo phosphorylation
D. Oxidative phosphorylation
E. * Substrate level phosphorylation
356.
In the complete process of photosynthesis, the _____.
A. Kory cycle yields CO2
B. * Light reactions release oxygen
C. Calvin cycle breaks down H2O
D. Light reactions produce NADP+ from NADPH + H+
E. All of the above
357.
In the electron transport chain, the hydrogen ions enter the inner compartment of
mitochondria through special channels formed by
A. * ATP synthase.
B. Coenzyme A
C. Acetyl CoA.
D. Oxygen.
E. Water
358.
In the mitochondria NADH and QH2 are oxidized by ____________.
A. Carbon dioxide
B. Hydrogen peroxide
C. Ozone
D. * Oxygen
E. Water
359.
In the presence of oxygen and in the absence of ADP, what occurs if the
uncoupler 2,4-dinitrophenol is added to a suspension of normal mitochondria 5 minutes
after an oxidizable substrate has been added?
A. The substrate will be oxidized until the addition of the 2,4-dinitrophenol which
blocks further oxidation.
B. There is no effect; oxidation of the substrate continues at the same rate before and
after the addition of 2,4-dinitrophenol.
C. The substrate cannot be oxidized either with or without 2,4-dinitrophenol unless
ADP is also present.
D. * Oxidation of the substrate does not occur until the 2,4-dinitrophenol is added.
Afterward, oxidation proceeds rapidly until all of the substrate is consumed.
E. The substrate will be reduced until the addition of the 2,4-dinitrophenol which
blocks further reduction
360.
In theory at least, the free energy provided by NADH is sufficient to form
__________ ATP molecules.
A. 1
B. 2
C. 3
D. 4
E. * More than 4
361.
Instant source of energy is ___________.
A. Amino acids
B. Sucrose
C. * Glucose
D. Fats
E. Vitamins
362.
Intermediary metabolism is the term applied to reactions that _______________.
A. Degrade molecules
B. Synthesize large molecules such as proteins
C. Convert glucose to pyruvate
D. * Involve low molecular weight metabolites
363.
364.
365.
366.
367.
368.
369.
370.
371.
E. Convert fats to fatty acid
Levels of ATP and ADP are maintained in cells by
A. Phosphotransferases
B. Nucleoside diphosphate kinase
C. Adenylate kinase
D. Oxidative phosphorylation
E. * All of the above
Most CO2 produced during aerobic cellular respiration is released during
A. Oxidative phosphorylation
B. Lactate fermentation.
C. * The Kreb’s cycle
D. Electron transport
E. Glycolysis.
Most CO2 produced during aerobic cellular respiration is released during
A. Oxidative phosphorylation
B. Lactate fermentation
C. * The Kreb’s cycle
D. Electron transport
E. Glycolysis
Most energy during cell respiration is harvested during
A. The Krebs cycle
B. * Oxidative phosphorilation
C. Glycolysis
D. Anaerobic respiration
E. Fermentation
Most oxidation reactions in microbial bioenergetics involve the
A. * Removal of electrons and hydrogens
B. Addition of electrons and hydrogens
C. Addition of oxygen
D. Removal of oxygen
E. None of the above
Organisms need a way of storing energy because _____.
A. A cell can't always immediately use all the energy it gets
B. An organism often has times when no energy is used
C. * A cell can release only stored energy
D. A cell cannot create energy and must get it from elsewhere in the organism
E. B and D
Oxidative phosphorylation is regulated by:
A. The availability of reduced cofactors from catabolic pathways.
B. The availability of the dNTPs.
C. * The availability of ADP and Pi.
D. A and C
E. A, B, and C
Oxidative phosphorylation requires all of the items listed below except
A. ATP synthase in the correct position in the membrane
B. Enzyme complexes embedded in a membrane
C. The flow of electrons from NADH and QH2 in the membrane
D. * A matrix more positively charged than the intermembrane space
E. A terminal electron acceptor which is O2 in mitochondria
Phosphorylation at the expense of ATP is catalyzed by __________.
A. Protein kinases
B. Phosphoryl isomerases
C. Phosphatases
D. * All of the above
E. None of the above
372.
Regardless of the electron or hydrogen acceptor used, one of the products of
fermentation is always:
A. ADP
B. ATP
C. NAD+
D. Pyruvate
E. * Alcohol
373.
Respiration in addition to producing energy also carry out the function of
A. * Producing the major part of body heat
B. Manufacturing food
C. Maintaining water levels
D. None of the above
E. All the above
374.
Several prosthetic groups act as redox centers in Complex I, including:
A. FMN, ubiquinone, iron-sulfur clusters, heme.
B. * FMN, ubiquinone, iron-sulfur clusters.
C. Heme, ubiquinone, iron-sulfur clusters.
D. All of the above
E. None of the above
375.
Studying biogeochemical cycles would help a scientist learn how
A. Energy flows through an ecosystem
B. * Substances move in and out of living organisms
C. Chemicals react
D. Fatty acids are formed
E. A and B
376.
Substrate-level phosphorylation differs from oxidative phosphorylation in that:
A. Substrate-level phosphorylation involves the transfer of electrons
B. Substrate-level phosphorylation only occurs in the cytosol
C. Oxidative phosphorylation only occurs in the cytosol
D. * Oxidative phosphorylation involves the transfer of electrons
E. GTP is always involved in substrate-level phosphorylation
377.
The amount of energy recovered as ATP can be estimated by free energy of
hydrolysis of
A. Phosphoester I bond in ATP
B. Phosphoanhydride bonds in ADP
C. Phosphoester bond I ADP
D. * Phosphoanhydride bonds in ATP
E. All of the above
378.
The amount of energy required to bring all molecules to a reactive state prior to a
chemical reaction is called the reaction's _____________.
A. Free energy of formation
B. * Activation energy
C. Van der Waal's energy
D. Go'
E. More than one of the above is correct
379.
The chemical energy generated by oxidations cannot be captured by
A. NADH
B. NADP
C. FMN
D. FAD
E. * Q
380.
The chemiosmotic theory explains
A. The phosphorylation of ADP
B. The electron transport chain
C. The differences between inner and outer mitochondrial membranes
D. * The source of energy for formation of mitochondrial ATP
E. Aerobic respiration
381.
The coenzyme electron carriers produced in the Krebs cycle are
A. ATP and ADP
B. Pyruvate and acetyl CoA
C. * FADH2 and NADH
D. NAD and NADH
E. NADH and ATP
382.
The coenzymes NAD and FAD carry electrons to the
A. Nucleus
B. Citric Acid cycle
C. Plasma membrane
D. * Electron transport system
E. Lysosoms
383.
The degradation of which class of biochemicals does not significantly contribute
to the release of energy to cells?
A. * Nucleic acids
B. Proteins
C. Lipids
D. Carbohydrates
E. B and C
384.
The direct energy source that drives ATP synthesis during respiratory oxidative
phosphorylation is
A. Oxidation of glucose to CO2 and water
B. The thermodynamically favorable flow of electrons from NADH to the
mitochondrial electron transport carriers
C. Tthe final transfer of electrons to oxygen
D. * The difference in H+ concentration on opposite sides of the inner mitochondrial
E. membrane
F. Thermodynamically favorable transfer of phosphate molecules (from glycolysis
and Krebs cycle intermediates) to ADP
385.
The electron transport chain consists all of the following except
A. NADH dehydrogenase
B. Cytochrome complex
C. * Oxygenase
D. Cytochrome c oxidase
E. Ubiquinone, Q
386.
The electrons released by FADH2 during its oxidation to FAD by the electron
transport system finally end up as part of this molecule:
A. Glucose
B. * Water
C. Carbon dioxide
D. ATP
E. ADP
387.
The electrons that enter the electron transport system are carried there by
A. NADH
B.
C.
D.
E.
FADH2
* Both A and B
Biotin
PALP
388.
The energy for all forms of muscle contraction is provided by:
A. * ATP
B. ADP
C. Phosphocreatine
D. Oxidative phosphorylation
E. Generated in the mitochondria of the cell
389.
The energy in glucose cannot be released by _____.
A. Glycolysis
B. * Burning
C. Respiration
D. Photosynthesis
E. None of the above
390.
The energy produced during respiration is stored in
A. Pyruvic acid
B. Carbon dioxide
C. Adenosine monophosphate
D. * Adenosine triphosphate
E. Sialic acid
391.
The energy that is necessary to break bonds in the reactant molecules and form
new bonds in the products is called:
A. Delta E
B. * Activation energy
C. Transition state
D. Spontaneous energy
E. None of the above
392.
The enzyme complexes associated with oxidative phosphorylation and the
electron transport chain can be classified as ___________ proteins.
A. * Integral membrane
B. Peripheral membrane
C. Lipid-anchored membrane
D. Water-soluble
E. Both a and c
393.
The enzymes of the Krebs cycle are located in the
A. Cytoplasm
B. Inter-membrane space of mitochondria
C. Vesicles of the ER
D. Outer membrane of the mitochondria
E. Matrix of the mitochondria
394.
The FADH2 formed during the TCA cycle enters the electron transport system at
which site?
A. NADH dehydrogenase
B. Cytochrome a
C. * Coenzyme Q
D. ATP synthase
E. Cytochrome c1
395.
The final electron acceptor in the electron transport system is _____.
A. FADH2
B. * O2
C. Coenzyme Q
D. Cytochrome b
E. Cytochrome c
396.
The first law of thermodynamics states that
A. Energy is the capacity to do work.
B. Doing work is defined as causing movement against a resisting force
C. Heat flows from a warmer body to a cooler body
D. * Energy is neither created nor destroyed
E. All of the above
397.
The flow of material through a reaction pathway usually depends on
________________.
A. * Control at several steps in the pathway
B. Control of the first step of the pathway
C. Covalent modification of the enzyme that catalyzes the reaction
D. Feed-forward activation
E. Control of the second step of the pathway
398.
The formation of ATP from ADP and phosphate at the expense of the energy
yielded by electron transport to oxygen is called:
A. * Oxidative phosphorylation
B. Substrate-level phosphorylation.
C. Tissue respiration
D. Peroxidation
E. Krebs cycle
399.
The function of ATP is
A. * To provide energy for cellular processes
B. Catalyze chemical reactions
C. Make up long polymer chains
D. Store energy for a long time
E. Ingibit chemical reactions
400.
The hydrolysis of the highest energy phosphate bond(s) in which of the following
compounds will release the most free-energy?
A. Phosphoenolpyruurvate
B. ADP
C. AMP
D. ATP
E. * The energy generated by hydrolysis of the highest energy phosphate bond in all
of the above is about the same.
401.
The immediate energy source that drives ATP synthesis by ATP synthase during
oxidative phosphorylation is:
A. The flow of electrons down the electron transport chain.
B. * The H+ concentration gradient across the inner mitochondrial membrane.
C. The oxidation of glucose and other organic compounds.
D. The transfer of phosphate to ADP.
E. The affinity of oxygen for electrons.
402.
The inner mitochondrial membrane contributes to the formation of a proton
gradient mainly because it
A. Contains ATP synthase complex
B. Is the location of specific transporter proteins
C. * Is a barrier to protons
D. Is not rich in proteins
E. Is rich in proteins
403.
The loss of hydrogen is known as
A.
B.
C.
D.
E.
Dehydration
Hydrogenation
Reduction
* Oxidation
Both D and D are correct
404.
The most important flavin-linked dehydrogenases in the mainstream of respiration
and electron transport, all localized in the:
A. ytosol
B. Nucleus
C. Rybosoms
D. * Mitochondria
E. Lysosoms
405.
The movement of protons through ATP synthase occurs from the
A. Matrix to the intermembrane space.
B. Matrix to the cytoplasm.
C. * Intermembrane space to the matrix.
D. Intermembrane space to the cytoplasm.
E. Cytoplasm to the intermembrane space.
406.
The notion that ATP is generated by a proton gradient existing across a membrane
is called
A. Proton motion.
B. * Chemiosmotic theory
C. Cytochromic flow
D. Lactate reduction
E. A and D
407.
The number of ATP molecules produced during aerobic and anaerobic respiration
are _____ and ________ respectively.
A. 2 and 38
B. 0 and 2
C. 38 and 0
D. * 38 and 2
E. 1-10
408.
The oxidation of a particular hydroxy substrate to a keto product by mitochondria
has a P/O ratio of less than 2. The initial oxidation step is very likely directly coupled to
the:
A. Oxidation of a flavoprotein
B. Oxidation of a pyridine nucleotide
C. * Reduction of a flavoprotein
D. Reduction of a pyridine nucleotide
E. Reduction of cytochrome a3
409.
The oxidizing agent in the enzyme superoxide dismutase is
A. Superoxide anion (.O2-)
B. H2O2
C. * Copper
D. O2
E. All of the above
410.
The oxygen utilized in cellular respiration finally shows up as
A. CO2
B. ATP
C. New O2
D. * H2O
E. Part of a sugar
411.
The part of the respiratory tract that is responsible for keeping it healthy is
________.
A. Trachea
B. Bronchi
C. Nasal cavity
D. * All the above
E. None of the above
412.
The process by which a cell is built up from the simple nutrients obtained from its
environment is called _____.
A. * Anabolism
B. Biosynthesis
C. Catabolism.
D. All of the above
E. More than one of the above, but not all
413.
The process by which the sun’s energy is trapped as the source of energy used by
virtually all living organisms?
A. Evolution
B. Metabolism
C. Adaptation
D. Homeostasis
E. * Photosynthesis
414.
The process complementary to respiration is __________.
A. Circulation
B. * Photosynthesis
C. Osmoregulation
D. Hydroregulation
E. None of the above
415.
The process shown is
A. Reduction and is endergonic
B. Reduction and is exergonic
C. Oxidation and is endergonic
D. Oxidation and is exergonic
E. A ang B
416.
The protonmotive force is a result of _______________________.
A. The flow of electrons from the matrix to the inner membrane space
B. * A combination of an electrical potential and a chemical potential
C. The flow of protons within the inner mitochondrial membrane
D. All of the above
E. None of the above
417.
The reaction, C6H6O6 + 6O2 = 6 CO2 + 6 H2O, when it occurs in living cells is
known as
A. * Aerobic fermentation
B. Anaerobic fermentation
C. Cellular respiration
D. Glycolysis
E. Oxidative phosphorylation
418.
The respiratory control center of humans is located in the
A. Blood-brain barrier
B. Alveoli
C. * Erythrocytes
D. Brainstem (medulla oblongata)
E. Trachea
419.
The respiratory exchange ratio (RER) is the ratio of:
A. * Volume of oxygen consumed _ volume of carbon dioxide produced
B. Volume of carbon dioxide produced _ volume of oxygen consumed
C. Volume of oxygen produced _ volume of carbon dioxide consumed
D. Volume of oxygen consumed _ body mass
E. Volume of oxygen consumed _ lung ventilation
420.
The role of oxygen in aerobic respiration is
A. To transport CO2
B. Most impotent in the Krebs cycle
C. To transport ekectrons in glycolysis
D. To provide electrons for the electron transport chain
E. * As the final hydrogen acceptor in the electron transport chain
421.
The sequence describing the flow of electrons in phagocytes producing
superoxide from oxygen is
A. O2 -> cytochrome b -> NADPH -> FADH
B. * NADPH -> FADH -> cytochrome b -> O2
C. NADH -> FADH -> cytochrome b -> O2
D. O2-> cytochrome b -> FADH -> NADPH
E. Cytochrome c -> cytochrome b -> NADPH -> FADH
422.
?The standard free energy (?G°') of ATP hydrolysis to ADP + Pi is about
A. +30 kJ/mol
B. +14 kJ/mol.
C. -14 kJ/mol.
D. * -30 kJ/mol.
E. -62 kJ/mol.
423.
The synthesis of one molecule of ATP from ADP requires _________ to be
translocated across the inner mitochondrial membrane.
A. One proton
B. * About two protons
C. Hundreds of protons
D. 1 mole of protons
E. 10 protons
424.
The term coupling in biochemistry can mean
A. Phosphorylating ADP along with the transport of electrons in mitochondria
B. Forming oxygen from superoxide anion
C. Linking reactions so that one cannot occur without the other
D. All of the above
E. * a and c
425.
The transfer of free energy from catabolic pathways to anabolic pathways is best
called
A. Feedback regulation
B. Bioenergetics
C. Cooperativity
D. * Energy coupling
E. Entropy
426.
The types of ‘work ‘ cells do include
A. Chemical workmaking and breaking bonds
B. Transport of nutrients into cells and waste products out
C. Movement of individual cells and stuff within a cell
D. Cells do not do work, only tissues do work
E. * A and c are correct
427.
Uncoupling of mitochondrial oxidative phosphorylation:
A.
B.
C.
D.
E.
428.
A.
B.
C.
D.
E.
429.
Allows continued mitochondrial ATP formation, but halts O2 consumption.
Halts all mitochondrial metabolism.
* Halts mitochondrial ATP formation, but allows continued O2 consumption.
Slows down the citric acid cycle.
Slows the conversion of glucose to pyruvate by glycolysis.
What needs the nutrients and oxygen carried by your blood?
rgan systems
rgans
* issues
ndividual cells
Spesific cells
What system transports oxygen and nutrients to the cells of your body?
The digestive system
A.
B.
C. *
D.
E. A and D
430.
What tissue we used for the detection of cytochrome oxidase?
A. Blood
B. * Spleen
C. Muscle
D. Liver
E. Heart
431.
What type of protein such as a channel protein cross the entire cell membrane?
A. Integral protein
B. Peripheral protein
C. * Transmembrane protein
D. Receptor protein
E. A and B
432.
What type of transport utilizes ATP?
A. * Active transport
B. Diffusion
C. Facilitated diffusion
D. Osmosis
E. Only B and C
433.
When 10,000 molecules of ATP are hydrolyzed to ADP and in a test tube, about
twice as much heat is liberated as when a cell hydrolyzes the same amount of ATP.
Which of the following is the best explanation for this observation?
A. Cells are less efficient at heat production than nonliving systems.
B. Cells convert some of the energy of ATP hydrolysis into other forms of energy
besides heat.
C. * Cells are open systems, but a test tube is a closed system.
D. The hydrolysis of ATP in a cell produces different chemical products than does
the reaction in a test tube.
E. The reaction in cells must be catalyzed by enzymes, but the reaction in a test tube
does not need enzymes.
434.
When a phosphate is transferred from a high-energy molecule of ADP to form
ATP it's referred to as _____.
A. Photophosphorylation
B. Substrate-level phosphorylation
C. * Oxidative phosphorylation
D. Citric cycle
E. Decarboxilation of pyruvat
435.
When O2 is reduced during the electron transport system, _____ is produced.
A. * H2O
B. CO2
C. ADP
D. Glucose
E. Pyruvat
436.
When the ?G'° of the ATP synthesis reaction is measured on the surface of the
ATP synthase enzyme, it is found to be close to zero. This is thought to be due to:
A. A very low energy of activation
B. Enzyme-induced oxygen exchange
C. Stabilization of ADP relative to ATP by enzyme binding
D. * Stabilization of ATP relative to ADP by enzyme binding
E. None of the above
437.
When xenobiotics are substrates for the protein called cytochrome P450, this
enzyme serves to
A. Provide oxidation
B. Solubilize natural metabolites
C. Solubilize steroids
D. * Solubilized drugs, anaesthetic, dyes and pesticides
E. All of the above
438.
Which has the highest reduction potential?
A. NADH
B. Complex I
C. Complex II
D. * O2
E. Cytochrom c
439.
Which is not generally a molecule used to conserve energy?
A. ATP
B. NADH
C. FAD
D. * QH2
E. All of the above
440.
Which is true for aerobic respiration but not true for anaerobic respiration?
A. CO2 is produced
B. ATP is produced
C. * Water is produced
D. Alcohol is produced
E. Pyruvate is produced
441.
Which is usually the slowest way to regulate a reaction in a metabolic pathway?
A. Allosteric modulation
B. Covalent modification
C. * Changing the enzyme concentration
D. All of the above are usually equally as fast
E. Competitive inhibitor
442.
Which metabolic pathway is common to both fermentation and cellular
respiration?
A. The Kreb’s cycle
B. Reduction of pyruvate to lactate
C. * Glycolysis
D. Synthesis of acetyl CoA from pyruvate
E. The electron transport chain
443.
Which molecule is an electron carrier that is carrying electrons?
A. NaCl
B. NAD+
C. * NADH
D. NH4
E. (NH4)2SO4
444.
Which of the following coenzymes would have to be continually present in the
cell in order for the oxidative reactions of glycolysis to continue?
A. FADH2
B. NADH
C. ATP
D. * NAD+
E. All of the above
445.
Which of the following is a coenzyme associated with cellular respiration?
A. NAD+
B. O2
C. FAD
D. * both A and C
E. PALP
446.
Which of the following is common to both cellular respiration and the light
reactions of photosynthesis?
A. The transfer of electrons to glucose
B. The chemiosmotic formation of ATP
C. * Oxygen is one of the byproducts
D. Mitochondria are essential organelles E. must have light
E. A and B
447.
Which of the following is correct concerning the mitochondrial ATP synthase?
A. It can synthesize ATP after it is extracted from broken mitochondria.
B. It catalyzes the formation of ATP even though the reaction has a large positive
?G'°.
C. It consists of F0 and F1 subunits, which are transmembrane (integral)
polypeptides.
D. It is actually an ATPase and only catalyzes the hydrolysis of ATP.
E. * When it catalyzes the ATP synthesis reaction, the ?G'° is actually close to zero.
448.
Which of the following is most similar in structure to ATP?
A. DNA helix
B. Phospholipid
C. RNA nucleotides
D. An anabolic steroid
E. * An amino acid with three phosphate groups attached
449.
Which of the following is not a factor contributing to the large free energy of
hydrolysis of ATP?
A. Electrostatic repulsion of oxygen atoms
B. Better solvation of products than ATP itself
C. * Complexes with Mg++ or Mn++ ions
D. Better stability of products than ATP itself
E. Electrical sheilding of products of hydrolysis
450.
Which of the following is not a part of adenosine diphosphate?
A. * Glucose
B. Adenine
C. Ribose
D. Two phosphate groups
E. All of the above
451.
Which of the following is true for all exergonic reactions?
A. A net input of energy from the surroundings is required for the reactions to
proceed.
B. The products have more total energy than the reactants.
C. The reactions are nonspontaneous.
D. * The reaction proceeds with a net release of free energy.
E. The reactants have more total energy than the products
452.
Which of the following is true for all exergonic reactions?
A. The products have more total energy than the reactants.
B. * The reaction proceeds with a net release of free energy.
C. A net input of energy from the surroundings is required for the reactions to
proceed.
D. Some reactants will be converted to products.
E. The reactions are nonspontaneous.
453.
Which of the following is true for exergonic reactions?
A. The reactions upgrade the free energy in the products at the expense of energy
from the surroundings.
B. A net input of energy from the surroundings is required for the reactions to
proceed.
C. * The products have less free energy than the reactants.
D. The products have more free energy than the reactants.
E. Reactants will always be completely converted to products.
454.
Which of the following produced a product used for synthesis of subsrate-level
phosphorylation?
A. Phosphophructikinase
B. Aldolase
C. * Glyceraldehyd-3-phosphate dehydrogenase
D. 1,3 – bisphophoglycerate mutase
E. All of the above
455.
Which of the following reactions contains steps which require an input of ATP
before they can be completed?
A. * Glycolysis
B. Kreb’s cycle
C. Electron transport system
D. A and b
E. B and c
456.
Which of the following statements about energy conservation in the
mitochondrion is false?
A. Drug that inhibits the ATP synthase will also inhibit the flow of electrons down
the chain of carriers.
B. For oxidative phosphorylation to occur, it is essential to have a closed
membranous structure with an inside and an outside.
C. The yield of ATP per mole of oxidizable substrate depends on the substrate.
D. * Uncouplers (such as dinitrophenol) have exactly the same effect on electron
transfer as inhibitors such as cyanide; both block further electron transfer to
oxygen.
E. Uncouplers “short circuit” the proton gradient, thereby dissipating the proton
motive force as heat.
457.
Which of the following statements about the chemiosmotic theory is false?
A. Electron transfer in mitochondria is accompanied by an asymmetric release of
protons on one side of the inner mitochondrial membrane.
B. Energy is conserved as a transmembrane pH gradient.
C. Oxidative phosphorylation cannot occur in membrane-free preparations.
D. The effect of uncoupling reagents is a consequence of their ability to carry
protons through membranes.
E. * The membrane ATPase, which plays an important role in other hypotheses for
energy coupling, has no significant role in the chemiosmotic theory.
458.
Which of the following statements about the mitochondrial inner membrane is
(are) not true?
A. The inner membrane is permeable to CO2, H2O, and small ions.
B. The inner membrane contains about 75% protein.
C. * The inner membrane contains many respiratory proteins.
D. The inner membrane is highly invaginated.
E. All of the above are true
459.
Which of the following statements about the mitochondrial inner membrane is
(are) not true?
A. The inner membrane is permeable to CO2, H2O, and small ions.
B. The inner membrane contains about 75% protein.
C. The inner membrane contains many respiratory proteins.
D. The inner membrane is highly invaginated.
E. * All of the above are true
460.
Which of the following statements are true about oxidative phosphorylation?
A. Electron transport provides energy to pump protons into the intermembrane space.
B. * An electrochemical gradient is formed across the inner mitochondrial
membrane.
C. Potassium and sodium ions form an ionic gradient across the inner mitochondrial
membrane.
D. A and B
E. A, B, and C
461.
Which of the following statements are true about oxidative phosphorylation?
A. Electron transport provides energy to pump protons into the intermembrane space.
B. An electrochemical gradient is formed across the inner mitochondrial membrane.
C. Potassium and sodium ions form an ionic gradient across the inner mitochondrial
membrane.
D. * A and B
E. A, B, and C
462.
Which of the following statements is false?
A. Phosphofructokinase is the rate limiting enzyme in glycolysis
B. Phosphorylase activity is higher in Type II fibres than in Type I fibres
C. Endurance training increases the amount of TCA cycle enzymes in muscle
D. * Oxygen is consumed in the TCA cycle
E. The heart can oxidise lactate
463.
Which of the following statements is TRUE concerning catabolic pathways?
A. They build up complex molecules such as protein from simpler compounds.
B. They combine molecules into more complex and energy-rich molecules.
C. They are spontaneous and do not need enzyme catalysis.
D. They involve endergonic reactions that break complex molecules into simpler
ones.
E. * They are usually coupled with anabolic pathways to which they supply energy
in the form of ATP.
464.
Which of the following takes place during oxidative phosphorilation in
mitochondria
A. Protons are pumped from the matrix to the intermembrane space
B.
C.
D.
E.
Protons are pumped from the intermembrane space to the matrix
Electrons are pumped from the matrix to the intermembrane space
* Electrons are pumped from the intermembrane space to the matrix
NADP is pumped from the matrix to the intermembrane space
465.
Which of the following would be considered one of a cell's electron carriers?
A. ATP
B. * NADH
C. FAD
D. All of the above
E. More than one of the above, but not
466.
Which statement does not explain why many biochemical processes are carried
out via multi-step pathways rather than by single-step reactions (or only a few steps)?
A. Multi-step pathways allow for more control points to regulate biochemical
processes.
B. * The end products of most pathways can usually be produced only by the
pathway reactions that nature has evolved.
C. Sharing of intermediates between pathways is facilitated this way.
D. There is greater control over the amounts of energy that are consumed or released
at any one time.
E. None of the above
467.
Which statement is false about most metabolic pathways?
A. * Most pathways are reversible under physiological conditions.
B. Pathways serve to increase the efficiency of energy transfers.
C. The rates of pathway reactions vary to respond to changing conditions.
D. The enzymes that catalyze reactions in metabolic pathways generally catalyze
only a single step.
E. Most pathways are irreversible under physiological conditions.
468.
Which statement is not true about catabolic pathways?
A. They have a net release of energy.
B. They have a net consumption of ATP.
C. They liberate smaller molecules from larger ones.
D. They include the citric acid cycle.
E. A and C only
469.
Which statement is true about two reactions that are coupled?
A. * One reaction will normally not occur without the other.
B. One is always exergonic and the other is always endergonic.
C. Only oxidation-reduction reactions can be coupled.
D. Coupled reactions are always driven by the ATP to ADP conversion.
E. B and C
470.
Which sugar is a part of adenosine diphosphate?
A. Adenine
B. * Ribose
C. Glucose
D. Glycogen
E. Water
471.
Which term most precisely describes the general process of breaking down large
molecules into smaller ones?
A. Anabolism
B. Catalysis
C. * Catabolism
D. Dehydration
E. Metabolism
472.
Why is ATP an important molecule in metabolism?
A. It energizes other molecules by transferring phosphate groups
B. Its phosphate bonds are easily broken
C. Hydrolysis of its phosphate groups is endergonic
D. Hydrolysis of its phosphate groups is exergonic
E. * A, b, and d are correct
473.
Why is ATP an important molecule in metabolism?
A. It energizes other molecules by transferring phosphate groups
B. Its phosphate bonds are easily broken
C. Hydrolysis of its phosphate groups is endergonic
D. Hydrolysis of its phosphate groups is exergonic
E. * A, b, and c are correct
474.
Within the inner matrix of the mitochondrion are:
A. * The enzymes of the tricarboxylic acid cycle (Krebs’ cycle)
B. The components of the electron transport chain
C. Glycogen molecules
D. The enzymes of gluconeogenesis
E. The enzymes creatine kinase and carnitine acyl transferase 1
475.
In which of the below-mentioned glycolysis reactions substrate level
phosphorylation takes place?
A. * pyruvate kinase
B. aldolase
C. phosphofructokinase
D. lactate dehydrogenase
E. hexokinase
476.
Name the glycolysis reactions, flowing with the formation of ATP:
A. hexokinase, enolase
B. enolase, aldolase
C. * phosphoglycerate kinase, pyruvate kinase
D. pyruvate kinase, lactate dehydrogenase
E. hexokinase, phosphofructokinase
477.
The concentration of blood lactate is normal:
A. 4,4-6,6 mmol/l
B. 3,3-5,5 mmol/l
C. 4,4-5,5 mmol/l
D. * 1-2 mmol/l
E. 5,5-6,6 mmol/l
478.
The preparatory stage of glycolysis ends with the formation of:
A. fructose-1,6-diphosphate
B. glucose-6-phosphate
C. * two trioses (dihydroxyacetone phosphate and glyceraldehydetryphosphate)
D. 2-phosphoglycerate
E. phosphoenolpyruvate
479.
Which glycolysis enzyme requires insulin as activator?
A. * hexokinase
B. glucose-6-phosphatase, phosphoglucomutase
C. glucose-6-phosphate-isomerase, aldolase
D. aldolase, lactate dehydrogenase
E. phosphoglucomutase, aldolase
480.
A basic role in digestion of carbohydrates in a digestive tract belongs following
enzymes:
A. Alfa-amylase, hexokinase, lactase
B.
C.
D.
E.
Maltase, sucrase, enterokinase
* Lactase, alfa-amylase, sucrase
Sucrase, maltase, glycogen phosphorylase
Aldolase, glucokinase, beta-amylase
481.
A patient is found to be deficient in the enzyme galactose 1-phosphate
uridylyltransferase. Specifically due to this deficiency what might a doctor recommend?
A. avoid all strenuous exercise
B. eat a fat-free diet
C. increase intake of vitamin C
D. * avoid ingestion of milk and milk products
E. all of the above.
482.
A UDP-galactose is used as a donor of galactose for the reaction of synthesis of:
A. Lactose (in a mammary gland)
B. Glycoproteins
C. Glycolipids
D. Proteoglycans
E. * All answers are correct
483.
Aerobic glycolysis is a multi-stage process of transformation of molecule of
glucose to pyruvate. Choose this process:
A. С6Н12О6 С3Н4О3
B. С6Н12О6 С5Н10О4
C. С6Н12О6 6 С2Н5ОН + 2 СО2
D. * С6Н12О6 2С3Н4О3
E. С6Н12О6 2С3Н6О3
484.
Aerobic oxidation of pyruvate to CO2 and H2O results in formation of molecules
ATP:
A. 38 ATP
B. 12 ATP
C. 3 ATP
D. * 15 ATP
E. 2 ATP
485.
An enzyme that catalyzes conversions of L-sugars to D-sugars is called an
A. Lyase
B. Hydrolase
C. Synthetase
D. Synthase
E. * Isomerase
486.
An intramolecular phosphoryl-group transfer occurs when:
A. 2-Phosphoglycerate is converted to phosphoenolpyruvate
B. 1,3 bisphosphoglycerate is converted to 3-phosphoglycerate
C. Both a and b
D. * All of the above
E. None of the above
487.
Anabolic and catabolic reactions in eukaryotes can occur simultaneously in cells.
This is possible because _______.
A. they all occur in the cytosol
B. the anabolic and catabolic pathways do not share any intermediate metabolites
C. of the compartmentation of metabolites for the reactions of the opposing
pathways
D. * all catabolic reactions are exergonic and all anabolic reactions are endergonic
E. None of the above
488.
Anaerobic glycolysis is a complex of reactions as a result of which the molecule
of glucose converts to the lactate or pyruvate. Choose this process:
A. С6Н12О6 С2Н5ОН + 2 СО2
B. С6Н12О6 С5Н10О4
C. С6Н12О6 С7Н14О7
D. * С6Н12О6 2С3Н6О3
E. С6Н12О6 2С3Н4О3
489.
Arsenate
A. Competes with NAD for the binding site in 1,3 bisphosphoglycerate
B. Competes with phosphate for its binding site in glyceraldehyde 3-phosphate
dehydrogenase
C. Produces a stable analog of 1,3 bisphosphoglycerate
D. All of the above
E. None of the above
490.
Arsenite
A. Poisons by the same mechanism as arsenate
B. Is less toxic than arsenate
C. * Binds tightly to lipoamide sulfur atoms
D. All of the above
E. None of the above
491.
ATP is a cosubstrate of the enzyme PFK-1. In most species ATP is also an
inhibitor of PFK-1 at higher concentrations. This seems to violate Le Chatelier's
Principle. Which statement below would provide a suitable explanation?
A. PFK-1 must be phosphorylated by ATP in the active site and the phosphorylated
PFK-1 must be the less active form.
B. There must be another cofactor interacting with ATP at high concentrations to
achieve inhibition of PFK-1.
C. ATP actually activates the reverse of the reaction preceding the PFK-1 step in the
pathway. It likely has no direct effect on PFK-1.
D. * There are two sites on PFK-1 that bind ATP. One is the active site; the other is
the regulatory site where inhibition occurs.
E. None of the above
492.
Choose from the below mentioned carbohydrates those, which contains a
galactose:
A. Hepatin
B. Maltose
C. Sucrose
D. Starch
E. * Lactose
493.
Choose the reaction of glycolysis, in which an inorganic phosphate takes part:
A. Glucose G glucose -6-phosphate
B. Fructose -6-phosphate - fructose -1, 6-biphosphate
C. * Glyceraldehyde 3-Phosphate 1,3- biphosphoglycerate
D. Glucose G glucose -1-phosphate
E. Pyruvate P lactate
494.
Choose the reaction of glycolysis, which catalyzed with phosphoglucoisomerase:
A. Glucose -6-phosphate - glucose -1-phosphate
B. Glucose -6-phosphate - glucose
C. Glucose G glucose -6-phosphate
D. * Glucose -6-phosphate - fructose -6-phosphate
E. Glucose -1-phosphate - fructose -6-phosphate
495.
Cofactors of dehydrogenases are all, except one:
A.
B.
C.
D.
E.
NAD+
* c-AMP
NADP+
FMN
FAD
496.
Compared to pyruvate, the carbon atoms in lactate ______________.
A. * are more reduced
B. are more oxidized
C. are equally as oxidized
D. carry more charge
E. All of the above
497.
Compared to pyruvate, the carbon atoms in lactate ______________.
A. * are more reduced
B. are more oxidized
C. are equally as oxidized
D. carry more charge
E. none of above
498.
Converting of glucose into lactic acid consists of eleven reactions. Almost of all
reactions as activators need ions:
A. Zn2+
B. Ca2+
C. ClD. Na+
E. * Mg2+
499.
During glycolysis, isomerization occurs during which of the following reactions:
A. Fructose 1,6 bisphosphate -> dihydroxyacetone phosphate and glyceraldehyde 3phosphate
B. Fructose 6 phosphate -> fructose 1,6 bisphosphate
C. Glucose 6- phosphate -> fructose 6- phosphate
D. Glucose -> glucose 6- phosphate
E. All of these
500.
During glycolysis, isomerization occurs during which of the following reactions:
A. Fructose 1,6 bisphosphate -> dihydroxyacetone phosphate and glyceraldehyde 3phosphate
B. Fructose 6 phosphate -> fructose 1,6 bisphosphate
C. * Glucose 6- phosphate -> fructose 6- phosphate
D. Glucose -> glucose 6- phosphate
E. None of the above
501.
Energetic value of anaerobic glycolysis:
A. * 2 ATP molecules
B. 10 ATP molecules
C. ATP molecules
D. 40 ATP molecules
E. 32 ATP molecules
502.
Enzyme that catalyzes the reaction of fructose-1,6-diphosphate disintegration into
two trioses in the process of glycolysis is named:
A. glucokinase
B. glucose-6-phosphatase
C. phosphofructikinase
D. * aldolase
E. enolase
503.
Enzyme that catalyzes the reaction of transformation acetaldehyde to ethanol is:
A.
B.
C.
D.
E.
pyruvate decarboxylase
malate dehydrogenase
lactate dehydrogenase
succinate dehydrogenase
* alcohol dehydrogenase
504.
Enzyme which catalyzes the first glycolysis reaction:
A. * hexokinase
B. glucose-6-phosphatase
C. phosphorylase
D. glucose-6-phosphate dehydrogenase
E. amylase
505.
Enzymes which catalyze the same reaction are called ___________.
A. * isozymes
B. complementary enzymes
C. cofactors
D. catalytes
E. All of the above
506.
For absorption of galactose and fructose into the enterocytes of intestine the
presence of such ions is needed:
A. Mg2+
B. Zn2+
C. * Na+
D. Ca2+
E. H+
507.
For transformation of fructose in fructose -1, 6-byphosphate, except for the proper
enzyme, needed:
A. ADP
B. NADP
C. Co A
D. * ATP
E. Fructose-1-phosphate
508.
Fragments containing three carbons can be transferred from a ketose phosphate to
an aldose phosphate by the enzyme ________________.
A. pyruvate carboxylase
B. * transaldolase
C. debranching enzyme
D. ribose-5-phosphate isomerase
E. none of the above.
509.
Fragments containing three carbons can be transferred from a ketose phosphate to
an aldose phosphate by the enzyme ________________.
A. pyruvate carboxylase
B. * transaldolase
C. debranching enzyme
D. ribose-5-phosphate isomerase
E. aconitase
510.
From the diet of a boy with such symptoms of galactosemia as vomiting, diarrhea,
underdevelopment, galactosuria, it is necessary to eliminate:
A. Fats
B. Meat, fish
C. * Milk and milk products
D. Tea, coffees
E. Fruits
511.
Fructose -6-phosphate in muscles, kidneys, adipocytes joins glycolysis by its
transformation under the action of phosphofructo kinase into fructose -1, 6-byphosphate.
Which components are needed for this reaction?
A. * ATP and Mg2+
B. AMP and Zn2+
C. GTP and Ca2+
D. UTP and Na+
E. GDP and Mg2+
512.
Galactose which an organism gets with food stuffs joins metabolism by
transformation of it into:
A. Ribulose-5- phosphate
B. Fruktozo-1,6-biphosphate
C. Glycerophosphate
D. Fructose-1- phosphate
E. * Glucose-1- phosphate
513.
Glucose 6-phosphate allosterically inhibits
A. Hexokinase I
B. Glucokinase
C. Hexokinase II
D. All of the above
E. * a and c only
514.
Glucose not part of a diet may be provided by degradation of
A. stored glycogen
B. starch
C. dextrin
D. * a and b
E. a, b and c
515.
Glucose-6-phosphate dehydrogenase deficiency is the ______________ which is
characterized by __________________________________________.
A. genetically determined disease; the absence of receptors to LDL on cells and
prominent atherosclerosis;
B. diet-induced disease; the deficit of thiamin in the organism and neurological and
cardiac symptoms;
C. * genetically determined disease; the low level of reduced glutathione in
erythrocytes and increased susceptibility of erythrocytes to hemolysis;
D. disease induced by environmental factors; the high level of oxidized glutathione
in the red blood cell and increased resistance of erythrocytes to hemolysis.
E. none of the above.
516.
Glucose, that arrive with blood from an intestine to the liver, is utillized for all
functions, except:
A. Formation of glycogen
B. Oxidation to CO2 and H2O with selection of energy
C. Convert into fats for stocking of energy
D. Carried by blood to the brain as source of energy
E. * Use for detoxification of ammonia
517.
Glyceraldehyde 3-phosphate dehydrogenase causes
A. The reduction and phosphorylation of glyceraldehyde 3-phosphate to produce 1,3
bisphosphoglycerate
B. The oxidation of a molecule of NAD+ to NADH
C. Neither a nor b
D. * Both a and b
E. The oxidation of a molecule of FAD
518.
Glycogen synthesis takes place in the following oragans:
A. brain and muscles;
B. * liver and muscles;
C. liver and kidney;
D. liver and pancreas.
E. all of the above.
519.
Glycolysis has 2 stages. The peculiarities of preparatory stage are:
A. phosphorylation and energy secretion
B. glycolysis metabolites oxidation
C. * energy usage
D. are performed the reactions of substrate phosphorylation
E. formation of pyruvate
520.
Glycolysis is defined as:
A. aerobic process in which glucose is transformed to CO2 and H2O;
B. anaerobic process in which glucose is transformed to pyruvate;
C. anaerobic process in which glucose is converted to pentoses and NADPH is
produced;
D. aerobic process in which glucose is converted to glycogen.
E. * anaerobic process in which glucose is transformed to lactate;
521.
Glycolysis takes place in:
A. mitochondria;
B. nucleus;
C. lysosomes;
D. * cytoplasm.
E. none of the above.
522.
Hamsters love to run on exercise wheels. Prolonged running at a high rate of
speed requires ATP. Could a hamster with a defective gene for the enzyme lactate
dehydrogenase meet the extra ATP demand for prolonged, fast wheel-running by
maintaining a high rate of glycolysis? Why or why not?
A. * No, not enough NAD+ can be regenerated for glycolysis to continue at a high
rate.
B. No, the defective gene will cause a rapid decline in pH in the muscles used for
running.
C. Yes, the defective enzyme has no effect on the glycolytic pathway.
D. Yes, the enzyme alcohol dehydrogenase will supply the needed NAD+ if the
lactose dehydrogenase cannot.
E. None of the above
523.
How does the number of molecules of ATP produced compare for conversion of
one molecule of either glucose or fructose to pyruvate?
A. fructose produces one less ATP than glucose
B. * fructose produces the same number of ATP's
C. fructose produces one more ATP than glucose
D. fructose produces twice the number of ATP compared to glucose
E. fructose produces two more ATP than glucose
524.
How many ATP molecules are formed with complete oxidation of glucose in
aerobic condition?
A. 2
B. 8
C. * 38
D. 42
E. 30
525.
How many ATP molucules are formed as a result of anaerobic oxidation of a
single glucose molecule (net output)?
A. * 2
B. 6
C. 8
D. 4
E. 1
526.
How many molecules of ATP have to be spent during glycolysis?
A. 1;
B. * 2;
C. 3;
D. 4.
E. 0
527.
How many substrate level phosphorylation reactions are in glycolysis?
A. 1;
B. * 2;
C. 3;
D. 4.
E. 0
528.
In anaerobic glycolysis which does not need mitochondrial respiratory chain, ATP
forms with:
A. * Two reactions of the substrate level phosphorylation
B. One reaction of the substrate level phosphorylation and oxidative phosphorylation
C. Three reactions of the substrate level phosphorylation
D. One reaction of the substrate level phosphorylation
E. Two reactions of the oxidative phosphorylation
529.
In cells which don’t have mitochondria (mature red cells), cells with low oxidize
ability (retina, malignant cells), the glycolic breaking up of glucose takes place to
product:
A. Glycogen
B. Pyruvate
C. CO2 and N2O
D. Acetyl-CoA
E. * Lactate
530.
In skeletal muscles and cells of brain the transfer of hydrogen from cytoplasmatic
NADH is carries out:
A. * Glycerophosphate shuttle system
B. Ionophores
C. Permeases
D. Carnytin
E. Malate-aspartate shuttle system
531.
In the cells of liver, myocardium and kidneys a malate-aspartate shuttle system on
one molecule of NADH provides formation:
A. 1 ATP
B. * 3 ATP
C. 8 ATP
D. 12 ATP
E. 15 ATP
532.
In the muscles of person, which executes a physical work, accumulates:
A. Glycogen
B. Pyruvate
C. * Lactate
D. Glucose
E. CO2 and N2O
533.
In the oxygen insufficiency glycolisis is used as the energy source. Select
glycolisis among the below mentioned processes.
A. * glucose to lactate oxidation
B. glucose to CO2 and H2O oxidation
C. pyruvate to acetyl CoA oxidation
D. glucose to glucuronic acid oxidation
E. glycogen to glucose oxidation
534.
In the process of alcohol fermentation, which in the human organism takes place
in the cavity of intestine, acetaldehyde is reduces to the ethanol with the:
A. NADPH•H+
B. FAD•H2
C. FMN•H2
D. * NADH•H+
E. CoQ•H2
535.
Lactate is formed from pyruvate in an ____________ organism in ____________
conditions.
A. yeast; aerobic;
B. animal; aerobic;
C. fungi; aerobic;
D. * animal; anaerobic.
E. yeast; aerobic.
536.
Last reaction of anaerobic glycolysis: Pyruvate P lactate is catalyzed with NADdependent enzyme:
A. Pyruvate kinase
B. Pyruvate dehydrogenase
C. * Lactate dehydrogenase
D. Lactase
E. Enolase
537.
Mature red cells, retina, medulla of kidneys, utilize energy mainly glycolytic
decomposition of glucose because in the cells of these organs and tissues:
A. The TCA does not function
B. The respiratory chain is absent
C. There are no any mitochondria
D. High activity of glycolytic enzymes
E. * All answers are correct
538.
Metabolite, formed in the process of glucose phosphorylation under influence of
hexokinase is:
A. * glucose-6-phosphate
B. fructose-1-phosphate
C. fructose-6-phosphate
D. glucose-1,6-diphosphate
E. fructose-1,6-diphosphate
539.
More than one step in the glycolytic pathway is subject to regulation. It might
seem most efficient to regulate only the first step of a pathway to avoid buildup of
intermediates and to conserve materials and energy. Why is the first step of glycolysis not
the only regulated step?
A. * Some sugars can enter the glycolytic pathway beyond the first step. If steps
other than step one were not regulated, the breakdown of these sugars would be
essentially uncontrolled.
B. Having more than one regulated step in the pathway allows for feedback
inhibition.
C. Control of a single step in a reaction pathway is difficult because the
concentrations of enzymes in cells are very low. It's easier to control more than
one enzyme than just one.
D. All the ATP in a cell would be depleted very quickly if only the first step of
glycolysis were regulated.
E. Both A and B
540.
Mutases are described as
A. Polymerases which catalyze phosphoryl group transfers
B. * Isomerases which catalyze the transfer of phosphoryl groups from one part of a
substrate molecule to another
C. Forming intermediate free phosphate (Pi)
D. All of the above
E. None of the above
541.
Name 2 products of the first reaction of penthosophosphate cycle which flows in a
liver:
A. Glucose and phosphatidic acid
B. NADH and pentose
C. Gluconic acid and ribulose
D. Glucose-1,6-diphosphate and NADPH
E. * 6-phosphogluconolactone and NADPH
542.
Name irreversible reactions of glycolysis :
A. * hexokinase, phosphofructikinase, pyruvatekinase
B. aldolase, hexokinase, lactate dehydrogenase
C. enolase, aldolase, pyruvatekinase
D. phosphoglyceratekinase, enolase, lactate dehydrogenase
E. pyruvatekinase, phosphoglyceratekinase, aldolase
543.
Name the glycolysis reaction, which requires ATP energy:
A. * hexokinase, phosphofructokinase
B. hexokinase, enolase
C. enolase, aldolase
D. pyruvatekinase
E. phosphoglucomutase, enolase
544.
On activating of molecule of glucose and preparation of it to the splitting on two
trioses in the glycolysis used:
A. 1 ATP
B. 5 ATP
C. * 2 ATP
D. 12 ATP
E. 8 ATP
545.
Once inside a cell, glucose is rapidly phosphorylated to glucose-6-phosphate.
What is the main purpose of this phosphorylation?
A. to keep glucose inside the cell
B. to form a high-energy compound
C. * to activate PFK-1
D. to prevent mutarotation
E. none of the above.
546.
Once inside a cell, glucose is rapidly phosphorylated to glucose-6-phosphate.
What is the main purpose of this phosphorylation?
A. * to keep glucose inside the cell
B. to form a high-energy compound
C. to activate PFK-1
D. to prevent mutarotation
E. All of the above
547.
Oxidation of carbohydrates in an organism is carried out by indirect and direct
ways. The followings processes belong to indirect, except:
A. Glycolysis
B. Oxidative decarboxilation of pyruvate
C. Cycle of Krebs
D. * Pentose-phosphate pathway
E. C and A only
548.
Pentoses which appear from glucose-6-phosphate in the pentosophosphate cycle
can be utillized in such aims:
A. On the biosynthesis of nucleotides
B. On the construction of nucleic acids
C. On the construction of coenzymes
D. Transformation in to fructose-6-phosphate
E. * All adopted processes are correct
549.
Pentosophosphate cycle oxidation of glucose provides reconstraction of NADPH
such processes:
A. Synthesis of fatty acids
B. Synthesis of cholesterol
C. Synthesis of bile acids from cholesterol
D. Inactivation of steroid hormones
E. All adopted processes are correct
550.
PFK-2 and fructose 2,6-bisphosphatase are two names for the same enzyme. The
name PFK-2 is used for the enzyme's catalysis of the phosphorylation of fructose 6phosphate to fructose 2,6-bisphosphate. The name fructose 2,6-biphosphatase is used for
its catalysis of the reverse reaction. What is unique about this enzyme that makes it
logical to use both names?
A. It is one of very few enzymes that can catalyze both the forward and reverse
reactions.
B. The enzyme is a monomer when catalyzing the phosphorylation reaction and a
dimer when catalyzing the reverse reaction.
C. The forward and reverse reactions occur in different compartments within the
cell, so a different name is used for each activity.
D. * The enzyme is bifunctional. The forward and reverse reactions are catalyzed by
different sites on the same enzyme.
E. all of the above.
551.
PFK-2 and fructose 2,6-bisphosphatase are two names for the same enzyme. The
name PFK-2 is used for the enzyme's catalysis of the phosphorylation of fructose 6phosphate to fructose 2,6-bisphosphate. The name fructose 2,6-bisphosphatase is used for
its catalysis of the reverse reaction. What is unique about this enzyme that makes it
logical to use both names?
A. It is one of very few enzymes that can catalyze both the forward and reverse
reactions.
B. The enzyme is a monomer when catalyzing the phosphorylation reaction and a
dimer when catalyzing the reverse reaction.
C. The forward and reverse reactions occur in different compartments within the
cell, so a different name is used for each activity.
D. * The enzyme is bifunctional. The forward and reverse reactions are catalyzed by
different sites on the same enzyme.
E. Both A and D
552.
Phosphofructokinase I deficiency results in:
A. * An overproduction of Fructose 6-phosphate
B. An overproduction of Fructose 1,6 bisphosphate
C. Fructose 1,6 bisphosphate deficiency
D. a and c only
E. none of the above.
553.
Phospholructokinase I deficiency results in:
A. An overproduction of Fructose 6-phosphate
B. An overproduction of Fructose 1,6 bisphosphate
C. Fructose 1,6 bisphosphate deficiency
D. * a and c only
E. All of the above
554.
Phosphorylation at the expense of ATP is catalyzed by __________.
A. * protein kinases
B. phosphoryl isomerases
C. phosphatases
D. all of the above
E. None of the above
555.
Phosphorylation of fructose catalyzes enzymes:
A. Hexokinase and enolase
B. * Fructokinase and nonespecific hexokinase
C. Phosphofructokinase and enolase
D. Phosphofructokinase and phosphoglucoisomerase
E. Fructose-1-phosphate aldolase and hexokinase
556.
Seven of the ten reactions in the glycolytic pathway have free energy values close
to zero. What does this tell us about those reactions?
A. They are near equilibrium reactions.
B. They are not control points for pathway regulation.
C. They are reversible reactions.
D. * All of the above.
E. None of the above.
557.
Substrate level phosphorylation
A. Describes the conversion of ADP into ATP with the addition of inorganic
phosphate every place throughout the cell
B. Describes the formation of ADP by phosphoryl group transfer from 1,3
bisphosphoglycerate
C. None of the above
D. * Both a and b
558.
Sucrase hydrolyses sucrose into:
A. glucose and galactose;
B. glucose and glucose;
C. * glucose and fructose;
D. glucose and mannose.
E. none of the above.
559.
The accumulation of phosphorylated monosaccharides in the hepatocytes does not
result in the osmotic transfer of water and swelling of cells because glucose -6-phosphate
converts into insoluble:
A. Starch
B. Dekstrins
C. * Glycogen
D. Cellulose
E. Triacylglycerol
560.
The activity of which glycolytic enzyme shown below is not used to control the
rate of glycolysis?
A. PFK-1
B. pyruvate kinase
C. * triose phosphate isomerase
D. hexokinase
E. glucokinase
561.
The activity of which glycolytic enzyme shown below is not used to control the
rate of glycolysis?
A. PFK-1
B. pyruvate kinase
C. * triose phosphate isomerase
D. hexokinase
E. None of the above
562.
The biological functions of glycolysis are the following, except:
A. getting energy by short way
B. * ATP formation by oxidative phosphorylation
C. ATP formation by substrate level phosphorylation
D. usage of intermediate metabolites for lipids synthesis
E. usage of metabolites fo glyconeogenesis
563.
The concentration of glucose in the blood is normal. Which of the belowmentioned figures proves this?
A. 3-10 mmol/l
B. * 3,3-5,5 mmol/l
C. 4-8 mmol/l
D. 10-15 g/l
E. 1-2 mmol/l
564.
The conversion of pyruvate to ethanol also causes the ______________.
A. * oxidation of NADH
B. production of ADP
C. consumption of O2
D. generation of an ion gradient across mitochondrial membranes
E. oxidation of FADH2
565.
The conversion of pyruvate to ethanol also causes the ______________.
A. * oxidation of NADH
B. production of ADP
C. consumption of O2
D. generation of an ion gradient across mitochondrial membranes
E. oxidation of FADH2
566.
The conversion of pyruvate to ethanol also causes the ______________.
A. * oxidation of NADH
B. production of ADP
C. consumption of O2
D. generation of an ion gradient across mitochondrial membranes
E. reduction of NAD
567.
The conversion of pyruvate to ethanol also causes the ______________.
A. * oxidation of NADH
B. production of ADP
C. consumption of O2
D. generation of an ion gradient across mitochondrial membranes
E. None of the above
568.
The end product of anaerobic glycolysis is:
A.
B.
C.
D.
E.
pyruvate
* lactic acid
ethanol
acetic acid
glycerine aldehyde
569.
The end produtcs of aerobic glucose oxidation:
A. lactic acid
B. * Pyruvate
C. CO2 and H2O
D. ethanol
E. acetaldehyde
570.
The enzyme that catalyzes the conversion of pyruvate to lactate is
______________.
A. lactate reductase
B. pyruvate kinase
C. lactoenolpyruvate
D. * lactate dehydrogenase
E. lactate oxidase
571.
The enzyme that catalyzes the conversion of pyruvate to lactate is
______________.
A. lactate reductase
B. pyruvate kinase
C. lactoenolpyruvate
D. * lactate dehydrogenase
E. lactate oxidase
572.
The enzyme that catalyzes the conversion of pyruvate to lactate is
______________.
A. lactate reductase
B. pyruvate kinase
C. lactoenolpyruvate
D. * lactate dehydrogenase
E. None of the above
573.
The enzyme which the key regulatory step in glycogen biosynthesis is
A. * Glycogen synthase
B. Glycogenin
C. Branching enzyme
D. Phosphoglucomutase
E. UDP-glucose pyrophosphorylase
574.
The family of GluT (glucose transporters) is:
A. * the proteins embedded into the cell membrane and facilitating the glucose
transport across the membrane;
B. the proteins embedded into the cell membrane and inhibiting the glucose transport
across the membrane;
C. the cytoplasmic proteins transporting glucose in the cytoplasm of cell;
D. the proteins of blood plasma transporting glucose via the blood.
E. none of the above.
575.
The glycerophosphate shuttle system on one molecule of cytoplasmatic NADH
provides formation:
A. 15 ATP
B. 12 ATP
C. 8 ATP
D. * 2 ATP
E. 3 ATP
576.
The glycolytic pathway oxidizes glucose to two molecules of pyruvate and also
produces a net of two molecules of ATP. ATP allosterically inhibits the enzyme, PFK-1,
that catalyzes the third step of glycolysis. This is an example of _____________.
A. feed-forward activation
B. * feedback inhibition
C. negative cooperativity
D. competitive inhibition
E. None of the above
577.
The inhibitor of phosphofructikinase in the glycolysis is:
A. * adenosine triphosphate
B. guanosine monophosphate
C. cytidine monophosphate
D. guanosine triphosphate
E. uridine diphosphate
578.
The inhibitors of phosphofructokinase (which catalyses transformation of fructose
-6-phosphate into fructose -1, 6-biphosphate) are:
A. AMP and ADP
B. AMP and lactate
C. ADP and malonate
D. ADP and ATP
E. * ATP and citrate
579.
The innate undigestion of fructose is related to the genetic defect of enzyme:
A. * Fructose-1-phosphate aldolase
B. Hexokinase
C. Phosphofruktokinase
D. Phosphoglucoisomerase
E. Enolase
580.
The key intermediate product of carbohydrate metabolism – glucose-6-phosphate
– can transformed in a liver by such ways, except:
A. From glucose-6-phosphate glycogen is synthesed
B. Glucose-6-phosphate under influence of specific phosphates split to free glucose
C. Spliting by glycolisis to pyruvate
D. Spliting to CO2 and H2O with selection energy of ATP
E. * Transforms in uracyl
581.
The main hormones that regulate the synthesis and decomposition of glycogen
are:
A. insulin, glucocorticoids, thyroxin;
B. glucagons, glucocorticoids, vasopressin;
C. * insulin, glucagons, epinephrine;
D. glucocorticoids, glucagons, epinephrine.
E. all of the above.
582.
The major regulatory enzyme of glycolysis is phosphofructokinase, the activators
of which are:
A. ATP and citrate
B. * AMP and ADP
C. Lactate and AMP
D. Malonate and ATP
E. Ions of Zn2+ and Na+
583.
The major regulatory step of the pentose phosphate pathway is catalyzed by which
enzyme?
A. transaldolase
B.
C.
D.
E.
phosphofructokinase-1
* glucose 6-phosphate dehydrogenase
ribose 5-phosphate isomerase
hexokinase
584.
The molecule 1,3-bisphosphoglycerate can be converted to 3phosphoenolpyruvate two ways. One way is catalyzed by the glycolytic pathway enzyme
phosphoglycerate kinase. The other route is a two step reaction sequence that uses the
enzymes bisphosphoglycerate mutase and 2,3-bisphosphoglycerate phosphatase. The
intermediate product of the two-step sequence is 2,3-BPG which is an allosteric inhibitor
of hemoglobin. What disadvantage would there be if the glycolytic pathway only used
the two-step reaction sequence?
A. * The step catalyzed by phosphoglycerate kinase is one of the ATP producing
steps of glycolysis. Using only the two-step reaction sequence would reduce the
number of ATP's produced.
B. There is no disadvantage to the two-step sequence other than having to use more
than one enzyme.
C. The molecule 2,3-BPG is also a potent inhibitor of PFK-1. Even transient
production of 2,3-BPG will significantly slow glycolysis.
D. Too much 2,3-BPG would be produced which would cause clumping of red blood
cells.
E. Both A and D
585.
The non-oxidative stage of the pentose phosphate pathway produces substances
that are intermediates of ___________.
A. * glycolysis
B. the citric acid cycle
C. the Cori cycle
D. glycogenolysis
E. none of the above.
586.
The non-oxidative stage of the pentose phosphate pathway produces substances
that are intermediates of ___________.
A. * glycolysis
B. the citric acid cycle
C. the Cori cycle
D. glycogenolysis
E. B and C
587.
The non-oxidative stage of the pentose phosphate pathway __________.
A. produces NADPH and releases CO2
B. * consists entirely of near-equilibrium reactions
C. contains two reactions whose enzymes are allosterically inhibited by NADPH
D. consumes four ATP molecules
E. produces FADH2 and releases CO2
588.
The non-oxidative stage of the pentose phosphate pathway produces substances
that are intermediates of ___________.
A. * glycolysis
B. the citric acid cycle
C. the Cori cycle
D. glycogenolysis
E. a and b
589.
The overall ‘G for glycolysis is -72 kJ/mol in erythrocytes. Which statement
below is true?
A. The value of ‘G0' is also -72 kJ/mol since the cytosol pH is close to 7.
B. The free energy of glycolysis is found as the sum of the standard free energy
changes for the individual pathway reactions.
C. * The negative sign of ‘G shows that this pathway will proceed toward product
(pyruvate) under normal cellular conditions.
D. All of the above.
E. None of the above
590.
The pentose phosphate pathway consists of _____ phases:__________________ .
A. three; oxidative, hydrolytic and reductive;
B. four; oxidative, nonoxidative, hydrolytic and reductive;
C. * two; oxidative and nonoxidative;
D. two; oxidative and reductive.
E. none of the above.
591.
The pentose phosphate pathway has two primary products. They are _________.
A. ATP and NADPH
B. oxaloacetate and acetyl CoA
C. sorbitol and fructose
D. * ribose-5-phosphate and NADPH
E. ribose-5-phosphate and FADH2
592.
The pentose phosphate pathway has two primary products. They are _________.
A. ATP and NADPH
B. oxaloacetate and acetyl CoA
C. sorbitol and fructose
D. * ribose-5-phosphate and NADPH
E. a and d
593.
The possible metabolic pathways for pyruvate in anaerobic conditions are:
A. conversion to lactate or acetyl CoA;
B. conversion to ethanol or acetyl CoA;
C. * conversion to lactate or ethanol;
D. conversion to lactate or ethanol or acetyl CoA.
E. all of the above.
594.
The preparatory stage of glycolysis ends with formation of glyceraldehyde-3phosphate and dioxyacetone phosphate. This reaction catalyzed by an enzyme:
A. Phosphoglyceratekinase
B. Hexokinase
C. Enolase
D. * Aldolase
E. Phosphoglyceratemutase
595.
The process of glucose oxidation in anaerobic condition is:
A. * glycolisis
B. glyconeogenesis
C. glycogenolysis
D. glycogenogenesis
E. lipolysis
596.
?The process of polysaccharides digestion in the gastrointestinal tract is catalized
by:
A. sucrase;
B. lactase;
C. maltase;
D. * D-amilase.
E. none of the above
597.
The product of aerobic glycolysis is:
A. 1,3- biphosphoglycerate
B.
C.
D.
E.
* Pyruvate
Acetyl-CoA
Enolphosphopyruvate
Lactate
598.
The products of lactose decomposition in the intestine are:
A. * glucose, galactose
B. glucose, fructose
C. fructose, galactose
D. maltose, ribose
E. ribose, glucose
599.
The products of sucrose decomposition in the intestine are:
A. glucose, galactose
B. * glucose, fructose
C. fructose, galactose
D. maltose, ribose
E. ribose, glucose
600.
The products, which are formed by the decomposition of fructose-1,6-diphosphate
in the glycolysis:
A. glycerol, pyruvate
B. * dihydroxyacetone phosphate, 3-phosphoglycerine aldehyde
C. pyruvate, dihydroxyacetone phosphate
D. lactic acid, acetyl CoA
E. acetyl CoA, glycerin
601.
The reaction of ethanol formation at the alcohol fermentation is catalyzed by an
enzyme:
A. Pyruvate dehydrogenase
B. Enolase
C. * Alcohol dehydrogenase
D. Lactate dehydrogenase
E. Pyruvate decarboxylase
602.
The reaction, which determines the glycolysis speed:
A. lactate dehydrogenase
B. * pyruvate kinase
C. glucose-6-phosphatase
D. aldolase
E. glucose-6-phosphate isomerase
603.
The reactions of alcohol fermentation and glycolysis are same to the stage of
pyruvate which farther under action of pyruvatedecarboxylase converts into:
A. Ethanol
B. Lactate
C. Glycerol
D. Glyceraldehyde
E. * Acetaldehyde
604.
The reason of development of cataract of children with galactosemia is a decrease
of activity of such enzyme in the lens as:
A. Glyucokinase
B. * Galactose-1- phosphate uridiltransferase
C. Galactomutase
D. Aldolase
E. UDP-glyucuronil transferase
605.
The sequence of glucose oxidation to lactate in peripheral tissues, delivery of
lactate to the liver, formation of glucose from lactate in the liver, and delivery of glucose
back to peripheral tissues is known as the ______.
A. glyoxylate cycle
B. Kreb's cycle
C. * Cori cycle
D. gluconeogenesis cycle
E. None of the above
606.
The sequence of reactions of alcohol fermentation is the same, as well as sequence
of reactions of glycolysis to the stage of such product formation:
A. * Pyruvate
B. Lactate
C. 3- phosphoglycerate
D. 2-phosphoglycerate
E. Two trioses
607.
The slowing of glycolysis in the presence of oxygen is called the ____________
effect.
A. Bohr
B. Michaelis-Menton
C. * Pastuer
D. Pauling
E. Fisher
608.
The slowing of glycolysis in the presence of oxygen is called the ____________
effect.
A. Bohr
B. Michaelis-Menton
C. * Pastuer
D. Pauling
E. None of the above
609.
The three control sites in glycolysis are the reactions catalyzed by:
A. hexokinase, phosphofructokinase 1 and aldolase;
B. phosphofructokinase 1, aldolase and pyruvate kinase;
C. hexokinase, aldolase and pyruvate kinase;
D. * hexokinase, phosphofructokinase 1 and pyruvate kinase.
E. all of the above.
610.
The transport of hydrogen from cytoplasm NADH to the respiratory chain of
internal mitochondrial membrane takes place with a help of:
A. Carnytin
B. Simple diffusion
C. * Malate-aspartate shuttle system
D. Permeases
E. Ionophores
611.
There are four enzymes that can catalyze the first step of glycolysis. They are
hexokinases I, II and III and glucokinase (hexokinase IV). Hexokinases I, II and III have
KM values near 0.1 mM. Glucokinase has a KM of 2-5 mM. If after a heavy meal the
blood glucose level rises to 8 mM which statement will be true?
A. At this high blood glucose level all four hexokinases are saturated with substrate.
B. * Hexokinases I, II and III are catalyzing at their maximum rate, but glucokinase
can still respond to increases in blood glucose levels.
C. None of the enzymes is saturated. All of them help to increase the rate of
glycolysis.
D. The flux through glucokinase will be extremely low. The only significant
catalysis is done by hexokinases I, II and III.
E. A and B correct
612.
Transfer of a high-energy phosphoryl group to ADP, resulting in ATP occurs
when:
A. 1,3 Bisphosphoglycerate -> 3-phosphoglycerate
B. * Phosphoenolpyruvate (PEP) -> pyruvate
C. 3-Phosphoglycerate -> 2-phosphoglycerate
D. Both a and b
E. all of the above.
613.
Transfer of a high-energy phosphoryl group to ADP, resulting in ATP occurs
when:
A. 1,3 Bisphosphoglycerate -> 3-phosphoglycerate
B. Phosphoenolpyruvate (PEP) -> pyruvate
C. 3-Phosphoglycerate -> 2-phosphoglycerate
D. * Both a and b
E. None of the above
614.
Transfer of the phosphoryl group from PEP to ADP is an example of
A. A mutase reaction
B. Isomerization
C. A dehydrogenase
D. * None of the above
E. Oxidation
615.
Transfer of the phosphoryl group from PEP to ADP is an example of
A. A mutase reaction
B. Isomerization
C. A dehydrogenase
D. * None of the above
E. Oxidation
616.
Transformation: D- galactose -1-phosphate + UDP-glucose D-glucose-1phosphate + UDP-1- galactose, catalyses an enzyme:
A. Hexokinase
B. Phosphoglucomutase
C. * Galactose-1- phosphate uridiltransferase
D. Glucokinase
E. UDP-galactopyrophosphorilase
617.
Transketolase and transaldolase are the enzymes of _______________ phase of
pentose phosphate pathway and they catalyze the ___________________________.
A. * nonoxidative; the exchange of two- and three-carbon fragments between sugar
phosphates;
B. oxidative; the conversion of glucose to ribulose 5-phosphate;
C. nonoxidative; the conversion of glucose to ribulose 5-phosphate;
D. oxidative; the exchange of two- and three-carbon fragments between sugar
phosphates
E. None of the above.
618.
Under starvation conditions, about how long does it take in humans for the body
to deplete the glycogen store in the liver?
A. 10 minutes
B. * 4 hours
C. 24 hours
D. 1 week
E. 2 weeks
619.
A.
B.
C.
D.
What are the effects of protein kinase A on PFK-2 and pyruvate kinase?
phosphorylates PFK-2; dephosphorylated pyruvate kinase; both enzymes are
inhibited
* phosphorylates both enzymes; inhibits both enzymes
dephosphorylates both enzymes; inhibits both enzymes
dephosphorylates PFK-2; phosphorylates pyruvate kinase; activates PFK-2;
inhibits pyruvate kinase
Both A and D
What chemical species activates the GLUT4 protein to transport glucose into
E.
620.
cells?
A. adrenaline
B. * insulin
C. protein kinase A
D. PFK-2
E. all of the above.
621.
What chemical species activates the GLUT4 protein to transport glucose into
cells?
A. adrenaline
B. * insulin
C. protein kinase A
D. PFK-2
E. glucagon
622.
What chemical species activates the GLUT4 protein to transport glucose into
cells?
A. adrenaline
B. * insulin
C. protein kinase A
D. PFK-2
E. None of the above
623.
What enzyme catalyzes transformation of fructose -6-phosphate into glucose -6phosphate?
A. Phosphofructokinase
B. Phosphoglucomutase
C. * Phosphoglucoisomerase
D. Triosophosphateisomerase
E. Enolase
624.
What enzyme transform glucose of meal in a liver into glucose-6-phosphate?
A. Phosphoglucomutase
B. Phosphatase
C. * Hexokinase
D. Fructokinase
E. Glucose isomerase
625.
What from the below mentioned functions is not proper to glycolysis?
A. Providing of organism energy at the hypoxia
B. Formation of dihydroxyacetone phosphate that is reduced to the glycerophosphate
C. Formation of pyruvate and lactate for their transformations in aerobic conditions
D. Energy source for malignant cells
E. * Synthesis ATP by the oxidative phosphorylation
626.
What is the function of pyruvate decarboxylase?
A. * The conversion of pyruvate to carbon dioxide and acetaldehyde.
B. To completely oxidize pyruvate to three molecules of carbon dioxide.
C. To convert phosphoenolpyruvate to pyruvate.
D. To regulate PFK-1.
E. The conversion of pyruvate to acetyl CoA
627.
What is the function of pyruvate decarboxylase?
A. * The conversion of pyruvate to carbon dioxide and acetaldehyde.
B. To completely oxidize pyruvate to three molecules of carbon dioxide.
C. To e. None of the above convert phosphoenolpyruvate to pyruvate.
D. To regulate PFK-1.
E. None of the above
628.
What is the prosthetic group of transketolase?
A. * thiamine pyrophosphate
B. biotin
C. pyridoxal phosphate
D. NAD+
E. FAD
629.
What types of reactions are involved in the two-step conversion of glucose to
fructose?
A. * reduction followed by oxidation
B. two sequential hydrolysis reactions
C. hydrolysis followed by isomerization (rearrangement)
D. phosphorylation followed by dephosphorylation
E. phosphorylation followed by reduction
630.
Where in the cell the glycolysis reactions are localized?
A. mitochondria
B. * cytoplasm
C. lysosomes
D. microsomes
E. nucleus
631.
Which amino acid's residue plays a role in the phosphoglycerate mutase reaction
in glycolysis for muscle and yeast?
A. Leucine
B. Lysine
C. Alanine
D. Histidine
E. All of the above
632.
Which amino acid's residue plays a role in the phosphoglycerate mutase reaction
in glycolysis for muscle and yeast?
A. Leucine
B. Lysine
C. Alanine
D. Histidine
E. All of above
633.
Which applies to fructose 1,6-bisphosphate?
A. inhibitor of pyruvate kinase
B. product of PFK-1 catalyzed step in glycolysis
C. isomer of glucose 1,6-bisphosphate
D. * all of the above
E. None of the above
634.
Which is a reasonable concentration for glucose in the blood?
A. 0.5 mM
B. * 5 mM
C. 50 mM
D. 5 M
E. 3.5 M
635.
Which is an intermediate formed in the conversion of glucose to fructose?
A. glucose-1-phosphate
B. * sorbitol
C. ribose
D. aldose reductase
E. pyruvate
636.
Which is not a function of the main products of the pentose phosphate pathway?
A. To maintain the reduced form of iron in hemoglobin.
B. To provide reducing power for the synthesis of fatty acids.
C. To serve as precursors in the biosynthesis of RNA and DNA.
D. * To raise the concentration of cAMP.
E. none of the above.
637.
Which is not a function of the main products of the pentose phosphate pathway?
A. To maintain the reduced form of iron in hemoglobin.
B. To provide reducing power for the synthesis of fatty acids.
C. To serve as precursors in the biosynthesis of RNA and DNA.
D. * To raise the concentration of cAMP.
E. D and C
638.
Which is not a possible fate of mitochondrial pyruvate?
A. conversion to oxaloacetate by pyruvate carboxylase
B. * conversion to phosphoenolpyruvate by pyruvate kinase
C. conversion to acetyl CoA
D. conversion to citrate for fatty acid synthesis
E. a, b and c
639.
Which is not among the possible fates of pyruvate after glycolysis?
A. conversion to lactate
B. further reduction by the citric acid cycle
C. conversion to ethanol
D. * used in the biosynthesis of alanine
E. all of the above.
640.
Which is not among the possible fates of pyruvate after glycolysis?
A. conversion to lactate
B. * further reduction by the citric acid cycle
C. conversion to ethanol
D. used in the biosynthesis of Alanine
E. None of the above
641.
Which is not among the possible fates of pyruvate after glycolysis?
A. conversion to lactate
B. further reduction by the citric acid cycle
C. conversion to ethanol
D. used in the biosynthesis of alanine
E. * all of the above
642.
Which metabolites link pentose phosphate pathway with glycolysis?
A. 3-phosphoglyserate, 2-phosphoglycerate;
B. phosphoenolpyruvate, pyruvate
C. fructose 1,6-biphosphate, phosphoenolpyruvate;
D. * fructose 6-phosphate, glucose 6-phosphate.
E. none of the above.
643.
Which molecule cannot be directly transported from the mitochondria to the
cytosol?
A. * oxaloacetate
B.
C.
D.
E.
acetate
malate
phosphoenolpyruvate
a and c
644.
Which of the following elements is required for the enzymatic reaction which
produces phosphoenolpyruvate?
A. Potassium
B. Calcium
C. * Magnesium
D. Manganese
E. Sodium
645.
Which of the following elements is required for the enzymatic reaction which
produces phosphoenolpyruvate?
A. Potassium
B. Calcium
C. * Magnesium
D. Manganese
E. Sodium
646.
Which of the following enzymatic reactions is/are control points for glycolysis:
A. Glucose 6-phosphate isomerase
B. Aldolase
C. Both a and b
D. * Neither a nor b
E. Mutase
647.
Which of the following is not a metabolically irreversible enzymatic reaction of
glycolysis?
A. Pyruvate kinase reaction
B. PFK-1 reaction
C. Hexokinase/Glucokinase reaction
D. * None of the above
E. All of the above
648.
Which of the following is not a metabolically irreversible enzymatic reaction of
glycolysis?
A. Pyruvate kinase reaction
B. PFK-1 reaction
C. Hexokinase/Glucokinase reaction
D. * None of the above
E. All of these
649.
Which of the following is not a metabolically irreversible enzymatic reaction of
glycolysis?
A. Pyruvate kinase reaction
B. PFK-1 reaction
C. Hexokinase/Glucokinase reaction
D. None of the above
E. * Aldolase reaction
650.
Which of the following is not regulated in glycolysis?
A. Pyruvate kinase
B. * Phosphoglycerate kinase
C. Hexokinase
D. PFK-1
E. all of the above.
651.
Which of the following is not regulated in glycolysis?
A.
B.
C.
D.
E.
Pyruvate kinase
* Phosphoglycerate kinase
Hexokinase
PFK-1
None of the above
652.
Which of the following is not regulated in glycolysis?
A. Pyruvate kinase
B. * Phosphoglycerate kinase
C. Hexokinase
D. PFK-1
E. None of above
653.
Which of the following is not regulated in glycolysis?
A. Pyruvate kinase
B. * Phosphoglycerate kinase
C. Hexokinase
D. PFK-1
E. Glucokinase
654.
Which of the following mutases catalyze the formation of a 2,3 BPG
intermediate?
A. Muscle phosphoglycerate mutases
B. Plant phosphoglycerate mutases
C. Yeast phosphoglycerate mutases
D. * a and c only
E. All of the above
655.
Which of the following mutases catalyze the formation of a 2,3 BPG
intermediate?
A. Muscle phosphoglycerate mutases
B. Plant phosphoglycerate mutases
C. Yeast phosphoglycerate mutases
D. * a and c only
E. All of the above
656.
Which substance causes muscles to ache during strenuous exercise?
A. pyruvic acid
B. lactose dehydrogenase
C. lactate ion
D. * lactic acid
E. acetyl CoA
657.
Which substance causes muscles to ache during strenuous exercise?
A. pyruvic acid
B. lactose dehydrogenase
C. lactate ion
D. * lactic acid
E. None of the above
658.
Which substance is not needed for the conversion of glucose to fructose?
A. NADPH
B. Aldose reductase
C. * QH2
D. NAD+
E. b and c
659.
Which way transformation galactose in a liver on glucose-6-phosphate?
A. By specific hecsoisomerase
B. Glicolitic to pyruvat, and farther – by gluconeogenesis
C. By glucomutase
D. By cytidiltransferase
E. * Galactose galactose-1-phosphatepglucose-1-phosphatepglucose-6-phosphate
660.
Why would it be desirable to slow glycolysis when the demand for ATP is high?
A. Inhibition of PFK-1 allows for the complete oxidation of pyruvate via the citric
acid cycle.
B. * Slowing glycolysis slows the rate of decrease in pH. A low pH can be harmful
and potentially fatal.
C. The less active form of PFK-1 is a potent allosteric activator of creatine, so even
though glycolysis is slowed, ATP production is actually increased by the
activation of creatine.
D. As PFK-1 is inhibited, its isozyme, PFK-2 is activated. PFK-2 is functional at a
much lower pH than PFK-1.
E. Slowing glycolysis slows the rate of increase in pH. A high pH can be harmful
and potentially fatal.
661.
Yeast will normally convert pyruvate to ethanol. Why is this better for the yeast
than a conversion to lactate?
A. Conversion to ethanol releases more NAD+ per mole than the conversion to
lactate.
B. The carbon atoms are more oxidized in ethanol than in lactate.
C. * Ethanol is neutral, but lactate production is accompanied by a sharp decrease in
pH.
D. Ethanol production is not better. Yeast normally produces ethanol and lactate in
equilmolar amounts.
E. A and B only
662.
Gluconeogenesis
A. Is concerned with synthesis of glycogen
B. Refers to the conversion of glycogen into glucose
C. * Refers to the ability of the liver to form precursors for glucose using fats and
proteins
D. Is a process resulting from deamination of amino acids
E. Is an essential part of the emulsification of fats
663.
A lack of blood glucose would have the greatest effects on
A. * The brain.
B. The heart.
C. The liver.
D. Skeletal muscles
E. Cardiac muscle
664.
A regulator of the enzyme Glycogen synthase is
A. Citric acid
B. 2, 3 bisphosphoglycerate
C. * Pyruvate
D. GTP
E. GDP
665.
ADP and AMP ___________________ gluconeogenesis.
A. Stimulate
B. * Inhibit
C. Do not effect
D. ADP stimulates and AMP inhibits
E. ADP inhibits and AMP stimulates
666.
Aerobic resynthesis of ATP occurs:
A. In the mitochondria in a process called glycogenolysis
B.
C.
D.
E.
* In the mitochondria in a process called oxidative phosphorylation
In the cytosol
In the sarcoplasmic reticulum
Only in Type I muscle fibres
667.
After glycogen has been used up in the postabsorptive state, which of the
following is usually used as the next source of energy?
A. * Glucose
B. Lipids
C. Proteins
D. Amino acids
E. Only B
668.
After the hepatic threshold for glycogen formation has occurred any excess
glucose in the blood is:
A. * Converted to lipid and stored as fat
B. Excreted by the kidney
C. Converted to urea
D. Is used in protein synthesis
E. B and c
669.
After the hepatic treshhold for glycogen formation has occurred, any excess
glucose in the blood is
A. * Converted to lipid and stored as fat
B. Excreted by the kidneys
C. Converted to urea
D. Is used in protein synthesis
E. B and C are correct
670.
All are true for ?-amylase EXCEPT:
A. Catalyzes hydrolysis of ? (1 4) linkages in starch.
B. Is an important component of saliva and pancreatic juice.
C. * Catalyzes hydrolysis of ? (1 6) linkages in amylopectin.
D. Catalyzes hydrolysis of ? (1 4) linkages in glycogen.
E. Activity is reduced in highly branched regions of polysaccharides and stops four
residues from any branch point.
671.
All of the following enzymes involved in the flow of carbon from glucose to
lactate (glycolysis) are also involved in the reversal of this flow (gluconeogenesis)
except:
A. 3-phosphoglycerate kinase.
B. Aldolase.
C. Enolase.
D. * Phosphofructokinase-1.
E. Phosphoglucoisomerase.
672.
All of the molecules below are examples of polymers of glucose subunits except:
A. * Chitin
B. Glycogen
C. Cellulose
D. Starch
E. Sucrose
673.
All of the molecules below are examples of polysaccharides except:
A. Glycogen
B. Cellulose
C. Starch
D. * Maltose
E. All of the above
674.
Amylose (a form of starch) and cellulose are both plant carbohydrate polymers.
What is the main structural difference between them?
A. Cellulose has many more branches than amylose
B. * Cellulose has ?-(1,4) glycosidic links and amylose has ?-(1,4) glycosidic links
C. Cellulose has ?-(1,4) glycosidic links and amylose has ?-(1,4) glycosidic links
D. Cellulose is a polymer of galactose, and amylose is a polymer of glucose
E. Cellulose is a polymer of glucose, and amylose is a polymer of galactose
675.
An enzyme involved in both glycolysis and gluconeogenesis is:
A. Hexokinase
B. Glucose-6-phosphatase
C. * 3-phosphoglycerate kinase
D. Phosphofructokinase-1
E. Pyruvate kinase
676.
An essential for converting Glucose to Glycogen in Liver is
A. Lactic acid
B. GTP
C. CTP
D. * UTP
E. FMN
677.
Anaerobic metabolism of glucose results in an oxygen debt that is the amount of
oxygen needed to metabolize the ______ that is produced.
A. Carbon dioxide
B. * Lactic acid
C. Glycogen
D. Fatty acid
E. Cholesterol
678.
Anaerobic metabolism refers to the generation of ATP:
A. Without the involvement of ADP
B. Without the use of glycogen
C. * Without the use of oxygen
D. In the absence of available oxygen
E. By the conversion of pyruvate to lactate
679.
Anaerobic respiration
A. * Is the primary metabolic pathway of cardiac muscle.
B. Is induced by ischemia.
C. Produces water and carbon dioxide as products.
D. Produces a maximum of 30 ATP
E. Produces oxygen as products
680.
Any compound that can be converted to __ can be a precursor for
gluconeogenesis.
A. Citrate
B. Pyruvate
C. Oxaloacetate
D. All of the above
E. * b and c
681.
Approximately how much energy is liberated when one gram of carbohydrate is
completely oxidised?
A. 4 kJ
B. 8 kJ
C. * 16 kJ
D. 24 kJ
E. 38 kJ
682.
As a result of anaerobic respiration in humans, glucose is converted to
A. * Pyruvic acid.
B. Lactic acid.
C. Citric acid.
D. Acetyl CoA.
E. Vitamin C
683.
As a result of glycolysis, linking step and the Krebs cycle each molecule of
glucose produces:
A. * 2 molecules of lactic acid
B. 6 molecules of carbon dioxide
C. 3 molecules of water
D. 3 molecules of carbon dioxide
E. 2 molecules of O2
684.
Blood glucose is actually:
A. * Absorbed from GI tract
B. Released by the muscles into the blood when it isn’t needed as energy source for
contraction
C. Glycogen from the liver
D. Glucagon which can be converted to sugar when glucose is needed for energy
source
E. The kinetic energy of the blood
685.
Cori cycle is
A. Synthesis of glucose
B. Reuse of glucose
C. Uptake of glycose
D. * Both (A) & (B)
E. Only C
686.
Cori’s cycle transfers
A. Glucose from muscles to liver
B. * Lactate from muscles to liver
C. Lactate from liver to muscles
D. Pyruvate from liver to muscles
E. Nonbe of the above
687.
Deficit of which enzyme is the base for the I type glycogenosis?
A. Glucose-6-phosphatase
B. * Hexokinase
C. Aldolase
D. Glycogen synthetase
E. Glucose-6-phosphate dehydrogenase
688.
Dietary fructose normally enters the glycolytic pathway by which of the following
mechanisms?
A. Phosphorylation to F-6-P by hexokinase.
B. Phosphorylation to F-1-P by fructokinase, cleavage by F-1-P aldolase.
C. Phosphorylation to F-1-P, isomerization to F-6-P by phosphofructomutase.
D. * A or B
E. A, B, or C
689.
Differentiate between the carbohydrate metabolic processes glycolysis and
gluconeogenesis. Name the following pathways: Releases glucose from glycogen
A. Glycolysis
B. Gluconeogenesis
C. Glycogenesis
D. * Glycogenolysis
E. Pentose phosphate pathway
690.
E 3,3 mmol/l
A. * 8,5 mmol/l
B. 2 mmol/l
C. 4,5 mmol/l
D. 5 mmol/l
691.
E The normal degradation of triglycerides into FFAs by adipose tissue is
impaired.
A. * The normal suppression of gluconeogenesis by insulin in the liver is impaired.
B. The normal uptake of glucose by skeletal muscle is impaired.
C. The normal glucose disposal, which includes glucose oxidation and glycogen
synthesis, by skeletal muscle, is impaired.
D. Excess free fatty acids (FFAs) impair c-cell function.
692.
Each of the following lines is the name of a disaccharide.
A. Galactose
B. Mannose
C. Glucose
D. * Maltose
E. Fructose
693.
Energy released by oxidation of glucose is stored as
A. concentration gradient across a membrane.
B. * TP
C. ADH.
D. DP.
E. oth b and c are correct.
694.
Ethanol decreases gluconeogenesis by
A. Inhibiting glucose-6-phosphatase
B. Inhibiting PEP carboxykinase
C. * Converting NAD+ into NADH and decreasing the availability of pyruvate
D. Converting NAD+ into NADH and decreasing the availability of lactate
E. Only B
695.
Excess glucose after a meal will first form glycogen in a process called
A. Glycolysis.
B. * Glycogenesis.
C. Lipogenesis.
D. Lipolyosis.
E. Gluconeogenesis
696.
Excessive intake of ethanol increases the ratio:
A. * NADH : NAD+
B. NAD+ : NADH
C. FADH2 : FAD
D. FAD : FADH2
E. Cyt. B; cyt. C
697.
For glycogenesis, Glucose should be converted to
A. Glucuronic acid
B. Pyruvic acid
C. * UDP glucose
D. Sorbitol
E. None of the above
698.
Fructose metabolism is not well regulated in the liver because:
A. * Fructose-1-phosphate aldolase allows fructose to bypass phosphofructokinase
B. More ATP is derived from glucose than fructose.
C. More ATP is derived from fructose than glucose.
D. lucose is the preferred substrate for hexokinase.
E. GLUT4 transports glucose, but not fructose into the liver.
699.
Glucocorticoids increase the level of glucose in the blood activating:
A. lycogenogenesis
B. Glycogenolysis
C. Gluconeogenesis
D. Ketogenesis
E. * Glycolysis
700.
Glucokinase and hexokinase are different from one another in all of the following
ways except:
A. Their location in the tissues
B. Their Km
C. Their Vmax
D. * The reaction they catalyze
E. Their inhibition by product
701.
Gluconeogenesis is increased in the following condition:
A. Diabetes insipidus
B. * Diabetes Mellitus
C. Hypothyroidism
D. Liver diseases
E. All of the above
702.
Glucose breakdown in certain mammalian and bacterial cells can occur by
mechanisms other than classic glycolysis. In most of these, glucose 6-phosphate is
oxidized to 6-phosphogluconate, which is then further metabolized by:
A. An aldolase-type split to form glyceric acid and glyceraldehyde 3-phosphate.
B. An aldolase-type split to form glycolic acid and erythrose 4-phosphate.
C. Conversion to 1,6-bisphosphogluconate.
D. * Decarboxylation to produce keto- and aldopentoses.
E. Oxidation to a six-carbon dicarboxylic acid.
703.
Glucose enters muscle cells mostly by:
A. Simple diffusion
B. * Facilitated diffusion using a specific glucose transporter
C. Co-transport with sodium
D. Co-transport with amino acids
E. Active transport
704.
Glucose enters muscle cells mostly by:
A. Simple diffusion
B. * Facilitated diffusion using a specific glucose transporter
C. Co-transport with sodium
D. Co-transport with amino acids
E. Active transport
705.
Glucose molecules entering skeletal muscle fibers are "trapped'' when converted
to
A. Pyruvic acid
B. Glucose 1-phosphate
C. * Glucose 6-phosphate
D. Glycogen
E. Lactic acid
706.
Glucose not part of a diet may be provided by degradation of
A. * Stored glycogen
B. Starch
C. Dextrin
D. A and b
E. A, b and c
707.
Glucose tolerance is decreased in
A. * Diabetes mellitus
B. Hypopituitarisme
C. Addison’s disease
D. Hypothyroidism
E. Anemia
708.
Glucose tolerance is increased in
A. Diabetes mellitus
B. * Adrenalectomy
C. Acromegaly
D. Thyrotoxicosis
E. Riscets
709.
Glucose-6-phosphate can serve as:
A. An intermedicate in glycolysis.
B. A precursor for the synthesis of glycogen.
C. An intermediate in gluconeogenesis.
D. A product of collagen degredation.
E. * A, B, C
710.
Glucose, labeled with 14C in different carbon atoms, is added to a crude extract of
a tissue rich in the enzymes of the pentose phosphate pathway. The most rapid production
of 14CO2 will occur when the glucose is labeled in:
A. * C-1.
B. C-3.
C. C-4.
D. C-5.
E. C-6.
711.
Glycerol is converted to ___________ when it is used for gluconeogenesis.
A. Dihydroxyacetone phosphate
B. Phosphoenolpyruvate
C. Oxaloacetate
D. * 3-phosphoglycerate
E. None of the above.
712.
Glycogen breakdown in exercising muscle is activated by:
A. Insulin
B. Cortisol
C. Increased pH
D. Amylase
E. * None of the above
713.
Glycogen breakdown in exercising muscle is activated by:
A. Insulin
B. Cortisol
C. Increased pH
D. Amylase
E. * None of the above
714.
glycogen in skeletal muscle?
A. Phosphorylase
B. Debranching enzyme
C. * ?-1-6-amyloglucosidase
D. Amylase
E. Gucose-6-phosphatase
715.
Glycogen is converted to glucose-1-phosphate by
A. UDPG transferase
B. Branching enzyme
C. * Phosphorylase
D. Phosphatase
E. None of the above
716.
Glycogen is converted to monosaccharide units by:
A. Glucokinase.
B. Glucose-6-phosphatase
C. * Glycogen phosphorylase.
D. Glycogen synthase.
E. Glycogenase.
717.
Glycogen is present in all body tissues except
A. Liver
B. * Brain
C. Kidney
D. Stomach
E. Pancreas
718.
Glycogen synthesis in vertebrates requires _____________ to activate glucose 1phosphate.
A. ATP
B. ADP
C. UTP
D. UDP
E. * All of the above
719.
Glycogen synthetase activity is depressed by
A. Glucose
B. Insulin
C. * Cyclic AMP
D. Fructokinase
E. Pyruvatdehydrogenase
720.
Glycogen while being acted upon by active phosphorylase is converted first to
A. Glucose
B. Glucose 1-phosphate and Glycogen with 1 carbon less
C. * Glucose-6-phosphate and Glycogen with 1 carbon less
D. 6-Phosphogluconic acid
E. None of the above
721.
Glycogenolysis is promoted by
A. * Glucagon
B. Growth hormone
C. Insulin
D. Cortisol (corticosteroids)
E. Both A and D are correct
722.
Glycogenolysis refers to
A. * The formation of glycogen
B. The formation of urea
C. Conversion of fat and/ or protein to glucose
D. The anaerobic metabolism of glucose
E. Conversion of glycogen to glucose
723.
Glycolysis
A. Requires the presence of oxygen
B.
C.
D.
E.
* Is the first step of cellular respiration
Produces carbon dioxide and water.
Pilizes FAD as an electron acceptor
Requires the presence of CO2
724.
Glycolysis in the erythrocyte produces pyruvate that is further metabolized to:
A. O2.
B. Ethanol.
C. Glucose.
D. Hemoglobin.
E. * Lactate.
725.
Glycolysis is inhibited by high concentrations of
A. Glucose.
B. Oxygen.
C. ADP.
D. * ATP.
E. All of above
726.
Glycolysis is the name given to the pathway involving the conversion of:
A. Glycogen to glucose-6-phosphate
B. Glycogen or glucose to fructose
C. * Glycogen or glucose to pyruvate or lactate
D. Glycogen or glucose to pyruvate or acetyl CoA
E. Glucose or fatty acids to pyruvate or acetyl CoA
727.
How certain carbohydrate pathways are reciprocally affected by insulin and
glucagon. The areas of focus will be:
A. Regulation of glycolysis by phosphorylation/dephosphorylation of key enzymes;
B. Regulation of glycogen formation vs. breakdown, again by phosphorylation/
dephosphorylation;
C. * How this regulation is coordinated so as to avoid futile cycling and trapping of
intermediates
D. How this regulation fits with the overall function of insulin vs. glucagon
E. None of the above
728.
How many grams of glucose is it necessary to eat for a patient to perform a
method of sugary loading
A. * 1 g per 1 kg of weight
B. 100 g
C. 20 g
D. 50 g
E. 10 g
729.
How many substrate level phosphorylation reactions are in glycolysis?
A. 1
B. * 2
C. 3
D. 4.
E. 0
730.
Hydrogen ions are formed when:
A. Glycogen becomes depleted
B. Phosphocreatine breakdown occurs
C. Pyruvate is converted to lactate
D. Pyruvate is converted to acetyl CoA
E. * lycolysis is being used as a major means of resynthesising ATP
731.
If excess glucose is present in the body, the glucose first will be stored as
__________ in muscle and the liver.
A.
B.
C.
D.
E.
Starch
* Glycogen
Cellulose
Fat
Vitamin C
732.
If glucose labeled with 14C in C-3 is metabolized to lactate via fermentation, the
lactate will contain 14C in:
A. All three carbon atoms.
B. Only the carbon atom carrying the OH.
C. * Only the carboxyl carbon atom.
D. Only the methyl carbon atom.
E. The methyl and carboxyl carbon atoms.
733.
If oxygen is unavailable, the pyruvate produced by glycolysis is converted into:
A. Alcohol
B. * Lactic acid
C. Carbon dioxide
D. Acetyl CoA
E. Water
734.
Immediately after exhaustive exercise, carbohydrate should be consumed to:
A. Restore liver glycogen
B. * Restore muscle glycogen
C. Provide the muscle with an energy source during recovery
D. CHO should not be consumed post exercise
E. None of the above
735.
In a eukaryotic cell, the enzymes of glycolysis are located in the:
A. Plasma membrane.
B. Inner mitochondrial membrane.
C. * Cytosol.
D. Mitochondrial matrix.
E. Intermembrane space.
736.
In a tissue that metabolizes glucose via the pentose phosphate pathway, C-1 of
glucose would be expected to end up principally in:
A. * Carbon dioxide.
B. Glycogen.
C. Phosphoglycerate.
D. Pyruvate.
E. Ribulose 5-phosphate.
737.
In addition to control of activity by phosphorylation, phosphorylase kinase is
activated by
A. Calmodulin
B. * Ca++
C. cAMP
D. Inhibitor-1
E. Na+
738.
In addition to energy (ATP), what is (are) the final product(s) of aerobic
respiration?
A. O2 and CO2
B. * CO2 and H2O
C. O2 and H2O
D. CO2 only
E. O2 only
739.
In an anaerobic muscle preparation, lactate formed from glucose labeled in C-2
would be labeled in:
A. All three carbon atoms.
B. * Only the carbon atom carrying the OH
C. Only the carboxyl carbon atom.
D. Only the methyl carbon atom.
E. The methyl and carboxyl carbon atoms.
740.
In anaerobic respiration, lactic acid is released into the blood from skeletal
muscle. When oxygen is available, most of the lactic acid is converted back to pyruvic
acid and glucose in the
A. Liver.
B. * Skeletal muscle
C. Heart.
D. Lung.
E. Kidney
741.
In comparison with the resting state, actively contracting human muscle tissue has
a:
A. Higher concentration of ATP.
B. * Higher rate of lactate formation.
C. Lower consumption of glucose.
D. Lower rate of consumption of oxygen
E. Lower ratio of NADH to NAD+.
742.
In general, the higher the intensity of exercise, the greater the proportional
contribution of:
A. Aerobic energy production
B. * Anaerobic energy production
C. The TCA cycle (Krebs’ cycle) to the production of ATP
D. The electron transfer chain to the production of ATP
E. Fat oxidation
743.
In glycolysis, glucose must be activated with the use of how many ATP
molecules?
A. 2
B. 3
C. 10
D. * 1
E. 5
744.
In glycolysis, how is ATP formed?
A. Through deamination
B. Through oxidative phosphorylation
C. * Through substrate level events
D. Through transfer of electrons
E. Through chemiosmosis
745.
In humans, gluconeogenesis:
A. * Helps to increase blood glucose during starvation.
B. Is used to convert fatty acids into glucose.
C. Is stimulated by the hormone insulin.
D. Requires the enzyme hexokinase.
E. Produces more ATP than it consumes.
746.
In the human skeletal muscle and brain cells, the energy yield per molecule of
glucose in aerobic respiration is ________ times higher than the energy yield in
anaerobic respiration.
A. * 2
B.
C.
D.
E.
16
18
19
20
747.
In the liver, kidney, and heart cells, the total number of ATP molecules generated
per glucose in aerobic respiration is
A. 2
B. 30
C. 36
D. * 38
E. 10
748.
Insulin decreases the level of blood glucose by:
A. * Gluconeogenesis activation
B. Gluconeogenesis oppression
C. Glucose phosphorylation oppression
D. Increase of glucose excretion with urine
E. Adrenalin excretion decrease
749.
Insulin facilitates energy storage in liver. Which enzymes of carbohydrate
metabolism are coordinately regulated in liver in response to insulin signaling?
A. Glycogen synthase
B. * Glycogen phosphorylase
C. Phosphofructokinase-1 (PFK-1)
D. Phosphofructokinase-2 (PFK-2)
E. Pyruvate kinase
750.
Lactic acid
A. Is produced as a result of aerobic metabolism of glucose.
B. * Is one of the normal end products of glycolysis
C. Is a common end product of red blood cells.
D. None of the above
E. All of the above
751.
Liver glycogen breakdown is stimulated by:
A. Insulin
B. Glucagon
C. Adrenaline
D. Both (a) and (b)
E. * Both (b) and (c)
752.
Liver glycogen breakdown is stimulated by:
A. Insulin
B. Glucagon
C. Adrenaline
D. Both (a) and (b)
E. * Both (b) and (c)
753.
Many people who are lactose intolerant can eat yogurt, which is prepared from
milk curdled by bacteria, with no problems. Why is this possible?
A. It is not possible (the statement in the question is not true); if one is lactose
intolerant, it is a genetic defect and cannot be altered
B. The bacteria convert all the lactose (milk sugar) to glucose
C. The bacteria convert all the lactose (milk sugar) to fructose
D. The bacteria convert all the lactose (milk sugar) to galactose
E. * The bacteria convert the disaccharide lactose into its component
monosaccharides, glucose and galactose; these resulting monosaccharides can be
tolerated
754.
Muscle and liver glycogen stores in a well nourished athlete would be sufficient to
sustain approximately how many minutes of submaximal exercise (if this were the only
energy source used)? The exercise is club level marathon pace.
A. 30 minutes
B. * 90 minutes
C. 180 minutes
D. 210 minutes
E. 300 minutes
755.
Muscle lactate production increases when:
A. Oxygen is readily available
B. Pyruvate cannot be formed from glucose breakdown
C. The pH of the muscle falls
D. * Glycolysis is activated at the onset of exercise
E. Muscle glycogen becomes depleted
756.
Name the substance which is the main energy source for brain:
A. Glycogen
B. Fructose
C. Lactic acid
D. Fatty acids
E. * Glucose
757.
Of the enzymes of carbohydrate metabolism listed below, which are
(de)phosphorylated in liver in response to insulin signaling?
A. Glycogen synthase
B. * Glycogen phosphorylase
C. Phosphofructokinase-1 (PFK-1)
D. Phosphofructokinase-2 (PFK-2)
E. Pyruvate kinase
758.
Once glycogen stores are filled, glucose and amino acids are used to synthesize
A. * Glycoproteins.
B. Proteins.
C. Lipids.
D. Lactic acid.
E. None of the above
759.
One of the following enzymes does not change glycogen synthase a to b.
A. Glycogen synthase kinases 3, 4, 5
B. Ca2+ calmodulin phosphorylase kinase
C. Ca2+ calmodulin dependent protein kinase
D. * Glycogen phosphorylase a
E. None of the above
760.
One of the net results of glycolysis is that:
A. Two FAD's are reduced
B. Two FAD's are oxidized
C. Two NAD to power of (exponent)'s are reduced
D. * D. Two NAD to power of (exponent)'s are oxidized
E. None of the above
761.
Pathway for synthesis of glycogen (from glucose)
A. Glycolysis
B. Gluconeogenesis
C. * Glycogenesis
D. Glycogenolysis
E. Pentose phosphate pathway
762.
Physiological glycosuria is met with in
A.
B.
C.
D.
E.
Renal glycosuria
* Alimentary glycosuria
Diabetes Mellitus
Alloxan diabetes
None of the above
763.
Possible fates of pyruvate produced by glycolysis include all of the following (not
necessarily in the same organism), except:
A. Oxidation to CO2 and water through the citric acid cycle.
B. Reduction to lactate by lactate dehydrogenase.
C. * Oxidation to ethanol by alcoholic fermentation.
D. Re-synthesis into glucose by gluconeogenesis.
E. Transamination to alanine.
764.
Pyruvate is converted to lactate during anaerobic metabolism. This reaction
produces one
A. H2O
B. ATP
C. FAD.
D. * NAD+.
E. None of the above.
765.
reactions involved in anaerobic glycolysis of glucose to lactate?
A. FAD/FADH2
B. * NAD+/NADH
C. glyceraldehyde-3-phosphate
D. ATP
E. ADP
766.
Select the molecule that is glucose and galactose connected by a covalent bond:
A. Maltose
B. * Sucrose
C. Cellulose
D. Lactose
E. Starch
767.
Select the reaction that is catabolic:
A. * Conversion of glucose into glycogen
B. Synthesis of hemoglobin
C. Conversion of sucrose into glucose and fructose
D. Synthesis of nucleic acids
E. Synthesis of fatty acid
768.
Select the sugar that is an important component of nucleotides:
A. Fructose
B. * Ribose
C. Galactose
D. Glucose
E. Sucrose
769.
Skeletal muscle and brain cells using aerobic respiration produce ____________
molecules of NADH which generates __________ molecules of ATP total.
A. * 2; 4
B. 10; 28
C. 10; 30
D. 10; 36
E. 1: 10
770.
Starch and glycogen are polymers of
A. Fructose
B.
C.
D.
E.
Mannose
* ?-?D-Glucose
Galactose
Cellulose
771.
Stimulation of adrenergic receptors has the effect of
A. Degrading glycogen
B. Activating protein kineses A and C
C. Lowering glycogen synthesis
D. * Reducing the effects of insulin
E. All of the above
772.
The ____ is the organ with an absolute requirement for blood glucose as its major
energy source.
A. * Brain
B. Heart
C. Skeletal muscle
D. Liver
E. Kedney
773.
The 4 rate limiting enzymes of gluconeogenesis are
A. Glucokinase, Pyruvate carboxylae phosphoenol pyruvate carboxykinase and
glucose-6-phosphatase
B. * Pyruvate carboxylase, phosphoenol pyruvate carboxykinase, fructose1,6
diphosphatase and glucose-6-phosphatase
C. Pyruvate kinase, pyruvate carboxylase, phosphoenol pyruvate carboxykinase and
glucose-6-phosphatase
D. Phospho fructokinase, pyruvate carboxylase, phosphoenol pyruvate
carboxykinase and fructose 1, 6 diphosphatase
E. None of the above
774.
The active form of glycogen ___ is phosphorylated; the active form of glycogen
___ is dephosphorylated.
A. Hydrolase; dehydrogenase
B. Dehydrogenase; hydrolase
C. Hydrolase; semisynthase
D. * Phosphorylase; synthase
E. Synthase; phosphorylase
775.
The aldolase reaction has a very unfavorable ?G' value (+23.8 kJ/mol). How can
this reaction be maintained as an easily reversible reaction in the cell?
A. * The concentration of F-1,6-BP is usually very high relative to products.
B. Elevation of body temperature to 37?C reverses the equilibrium.
C. Hydrolysis of the 1-phosphate from F-1,6-BP makes the reaction favorable.
D. A and B
E. A, B and C
776.
The appropriate sequence for the transaldolase catalyzed reaction would be (select
a capital letter from A to E):
A. * Reactive enamine attack on the aldehyde group of an aldose
B. beta-cleavage of Schiff base intermediate to release an aldose
C. Formation of Schiff base intermediate of a new ketose
D. Active site lysine forms Schiff base with keto-carbonyl group
E. Schiff base hydrolysed to ketose and enzyme
777.
The blood sugar raising action of the hormones of suprarenal cortex is due to
A. * Gluconeogenesis
B. Glycogenolysis
C. Glucagon-like activity
D. Due to inhibition of glomerular filtration
E. Glycoyisis
778.
The brain prefers to use _______ for fuel.
A. Vitamins
B. Protein
C. Lipids
D. Carbohydrates
E. All of the above
779.
The branching enzyme acts on the glycogen when the glycogen chain has been
lengthened to between glucose units:
A. 1 and 6
B. 2 and 7
C. 3 and 9
D. * 6 and 11
E. 1 and 2
780.
The breakdown of glycogen to form glucose occurs
A. * In the liver by phosphorolysis.
B. In the muscles by phosphorolysis
C. In the liver by hydrolysis.
D. In the muscles by hydrolysis.
E. The first two choices are both correct.
781.
The cause of insulin dependent diabetes (type I) is:
A. * Malfunction of structure and insulin receptors function
B. Decreased insulin synthesis
C. Increased insulin synthesis
D. Increased epinephrine synthesis
E. Decreased epinephrine synthesis
782.
The characteristic enzymes of gluconeogensis are found in the cytosol, except for
A. Pyruvate carboxlyase, which is in the mitrochondria.
B. Fructose-1,6-bisphosphatase, which is in the mitochondria
C. * Glucose-6-phosphatase, which is in the mitrochondria.
D. Fructose-1,6-bisphosphatase, which is in the glycogen granule.
E. Pyruvate carboxylase, which is in the glycogen granule
783.
The complete oxidation of glucose ultimately yields as products:
A. Acetyl CoA
B. Carbon dioxide and water
C. * Lactic acid
D. Pyruvate
E. O2
784.
The complex carbohydrate (polysaccharide) that is digested to the
monosaccharide, glucose, and is found in vegetables, fruits, and grains and is called
A. Maltose.
B. Starch.
C. Glycogen.
D. * Cellulose.
E. None of the above
785.
The conversion of glucose and oxygen into carbon dioxide and water is both a:
A. * Catabolic and reduction reaction
B. Anabolic and oxidation reaction
C. Catabolic and oxidation reaction
D. Anabolic and reduction reaction
E. Only B
786.
The conversion of noncarbohydrate molecules into glucose, is an example of
A. Glycogenolysis.
B. Glycogenesis.
C. * Gluconeogenesis
D. Glycolysis
E. Krebs cycle
787.
The conversion of one molecule of glucose to two molecules of pyruvate results in
the net formation of:
A. Six molecules of water
B. * Two molecules of ATP
C. Three molecules of ATP
D. Thirty-eight molecules of ATP
E. Thirty-nine molecules of ATP
788.
The conversion of oxaloacetate to malate by mitochondrial malate dehydrogenase
can be important in gluconeogenesis because:
A. It's the only way that carbons from oxaloacetate can get out of the mitochondrion.
B. * It is a reduction, so it allows carbons from oxaloacetate and electrons from
C. NADH to get out of the mitochondrion.
D. It is an oxidation, so it allows exchange of oxaloacetate carbons from
theImitochondrion for electrons from NADH in the cytosol.
E. Malate is an obligatory intermediate in gluconeogenesis. This is so confusing that
there is no logical answer to this question.
789.
The disaccharide that most people think of as table sugar is
A. * Sucrose.
B. Lactose.
C. Maltose.
D. Fructose.
E. Only B
790.
The end product of sugar metabolism is/are?
A. Maltose, lactose and sucrose
B. Carbon dioxide, water and heat and energy
C. Urea
D. * Glucose and other simple sugars
E. Glycerol
791.
The energy charge of the cell is:
A. The difference between the charge on the outside and inside of a cell
B. Generated by the sodium-potassium ATPase
C. The overall rate of energy use by the cell
D. * The extent to which the total adenine nucleotide pool is phosphorylated
E. The sum of the ATP, ADP and AMP concentrations in the cell
792.
The energy currency of the cell is
A. Starch
B. * Glycogen.
C. Glucose.
D. ATP.
E. None of the above
793.
The enzymes involved in Phosphorylation of glucose to glucose 6- phosphate are
A. Hexokinase
B. Glucokinase
C. Phosphofructokinase
D. * Both (A) and (B)
E. None of the above
794.
The enzymes of glycolysis are located in the:
A. Mitochondrion
B. Nucleus
C. * Cytoplasm
D. Lysosomes
E. Interstitial fluid
795.
The enzymes of glycolysis are located in the:
A. Mitochondrion
B. Nucleus
C. * Cytoplasm
D. Lysosomes
E. Interstitial fluid
796.
The glycolytic pathway (Glucose --> 2 Pyruvate) is found
A. * In most living organisms.
B. In all living organisms.
C. Primarily in animals.
D. Only in eukaryotes.
E. Only in yeast.
797.
The initiation of glycogen synthesis (ie the very first glucose residue added )
occurs by transfer of glucose from UDP-glucose to the:
A. * 4-position of free glucose.
B. 2-position of fructose.
C. Non-reducing end of maltose.
D. Serine-OH group of glycogen synthase.
E. Tyrosine-OH group of glycogenin.
798.
The linking reaction between glycolysis and Krebs cycle is:
A. The conversion of pyruvate into lactic acid
B. The conversion of pyruvate into acetyl-CoA
C. * The conversion of NAD to power of (exponent) into NADH
D. The conversion of 1,6 fructose phosphate to 3 phosphoglycerate
E. None of the above
799.
The low intake of carbohydrate in the diet:
A. Does not influence exercise performance in events lasting less than 10 minutes
B. Affects the resting muscle pH
C. * May impair high intensity exercise performance
D. Results in greater reliance on muscle glycogen during exercise
E. Is associated with a metabolic alkalosis
800.
The major source of carbohydrate in a typical Western diet is:
A. * Starch
B. Cellulose
C. Glycogen
D. Sucrose
E. Saccharin
801.
The metabolic function of the pentose phosphate pathway is:
A. Act as a source of ADP biosynthesis.
B. * Generate NADPH and pentoses for the biosynthesis of fatty acids and nucleic
acids.
C. Participate in oxidation-reduction reactions during the formation of H2O.
D. Provide intermediates for the citric acid cycle.
E. Synthesize phosphorus pentoxide.
802.
The metabolic pathway that results in the splitting of a glucose molecule into two
pyruvate molecules is:
A.
B.
C.
D.
E.
* Glycolysis
Oxidative phosphorylation
Krebs cycle
Cori cycle
Decarboxilation of pyruvat
803.
The monosaccharide that can be considered the most important source of energy
in the body is:
A. * Glucose
B. Glycogen
C. Starch
D. Fructose
E. Galactose
804.
The most rapid method to resynthesise ATP during exercise is through:
A. Glycolysis
B. * Phosphocreatine breakdown
C. Tricarboxylic acid cycle (Krebs’ cycle)
D. Glycogenolysis
E. Gluconeogenesis
805.
The net production of ATP via substrate-level phosphorylation in glycolysis is:
A. * 2 from glucose and 3 from glycogen
B. 2 from glucose and 4 from glycogen
C. 3 from glucose and 4 from glycogen
D. 3 from glucose and 2 from glycogen
E. 3 from glucose and 3 from glycogen
806.
The normal glucose tolerance curve reaches peak is
A. 15 min
B. * 1 hr
C. 2 hrs
D. 2. hrs
E. 13 min.
807.
The oxidation of 3 mol of glucose by the pentose phosphate pathway may result in
the production of:
A. 2 mol of pentose, 4 mol of NADPH, and 8 mol of CO2.
B. 3 mol of pentose, 4 mol of NADPH, and 3 mol of CO2.
C. * 3 mol of pentose, 6 mol of NADPH, and 3 mol of CO2.
D. 4 mol of pentose, 3 mol of NADPH, and 3 mol of CO2.
E. 4 mol of pentose, 6 mol of NADPH, and 6 mol of CO2.
808.
The patient L., 46 years, complains on the dry mouth, thirst, often urination,
general weakness. Biochemical blood investigation showed hyperglycemia,
hyperketonemia. In the urine: glucose, ketone bodies. Possible diagnosis is:
A. * Diabetes mellitus
B. Aimentary hyperglycemia
C. acute pancreatitis
D. diabetes insipidus
E. ischemic heart disease
809.
The patient with diabetes mellitus has hypoglycemic coma. The reasons for this
can be:
A. * Overdosage of insulin
B. Starvation
C. Dehydration of the organism
D. Hyperproduction of epinephrin
E. Addison's disease
810.
?The precursor of glycogen in the glycogen synthase reaction is
A. Glucose-1-P
B. Glucose-6-P
C. * DP-glucose
D. TP-glucose
E. None of the above
811.
The process in which glucose is converted to a storage form
A. * Is called glycogenolysis
B. Requires vitamin A.
C. Results in beta oxidation
D. Occurs in the liver.
E. Is very energy consuming
812.
The production of glucose-breakdown products from protein is called
A. Glycolysis
B. * Gluconeogenesis
C. Glycogenesis
D. Glycogenolysis
E. None of the above
813.
The rate of blood lactate accumulation is determined by:
A. The rate of muscle lactate production and the rate of muscle lactate efflux
B. The rate of anaerobic glycolysis
C. The rate of muscle glucose uptake
D. The rate of muscle glycogen depletion
E. * The difference between the rate of lactate appearance and the rate of lactate
clearance
814.
The regulation of normal blood sugar level is accomplished by
A. * Insulin, glucagons and adrenalin
B. Cell tissue absorption of glucose from the blood
C. The breakdown of glycogen by the liver
D. Glycogenesis and glycogenolysis
E. All of the above
815.
The regulation of the glycolytic pathway involves
A. * Feedback inhibition by ATP.
B. Allosteric inhibition by ATP.
C. Allosteric stimulation by ADP.
D. All three are correct.
E. Only a) and b) are correct.
816.
The steps of glycolysis between glyceraldehyde 3-phosphate and 3phosphoglycerate involve all of the following except:
A. ATP synthesis.
B. Catalysis by phosphoglycerate kinase.
C. * Oxidation of NADH to NAD+.
D. The formation of 1,3-bisphosphoglycerate.
E. Utilization of Pi.
817.
The synthesis of glucose from lactate, glycerol, or amino acids is called:
A. Glycogenolysis
B. Glycolysis
C. Lipolysis
D. * Gluconeogenesis
E. Transamination
818.
The synthesis of glucose from pyruvate by gluconeogenesis
A. * Requires the participation of biotin
B.
C.
D.
E.
Occurs exclusively in the cytosol
Is inhibited by elevated level of insulin
Requires oxidation/reduction of FAD
None of the above
819.
The synthesis of glycogen from glucose subunits is an example of this type of
reaction:
A. Hydrolysis
B. Oxidation
C. * Phosphorylation
D. Condensation
E. None of the above
820.
The tissues with the highest total glycogen content are
A. Muscle and kidneys
B. Kidneys and liver
C. * Liver and muscle
D. Brain and Liver
E. All of the above
821.
The total glycogen content of the body is about ______ gms.
A. 100
B. 200
C. * 300
D. 500
E. 230
822.
The two glycolytic intermediates that directly link glucose metabolism to the
metabolism of triglycerides, and thereby linking carbohydrate to fat metabolism are
A. Pyruvic acid and phosphoglyceraldehyde
B. Acetyl CoA and pyruvic acid
C. * Phosphoglyceraldehyde and acetyl CoA
D. Glucose and pyruvic
E. A and B
823.
The ultimate electron acceptor in the fermentation of glucose to ethanol is:
A. * Acetaldehyde.
B. Acetate.
C. Ethanol.
D. NAD+.
E. Pyruvate.
824.
This is the property of carbohydrates that make them readily dissolvable into
water:
A. The electronegativity of the carbon atom
B. Their ability to form polymers
C. * The presence of hydroxyl groups
D. The long carbon chains they form
E. None of the above
825.
To the resuscitation unit was delivered an infant with the following symptoms:
vomiting, diarrhoea, growth and development malfunction, cataract, mental deficiency.
The diagnosis was galactosemia. The deficit of which enzyme occure?
A. Hexose-6-phosphatase
B. * Galactose-1-phosphate uridiltransferase
C. Uridine diphosphate-glucose-4-epimerase
D. Uridine diphosphate-glucose-pyrophosphorylase
E. Glucose-6-phosphate dehydrogenase
826.
To which additional adrenergic receptor subtype does epinephrine bind in order to
further activate glycogen phosphorylase in liver?
A. Alpha-1
B. Alpha-2
C. Beta-1
D. * A novel beta-3 subtype
E. None of the above
827.
Transfer of high-energy phosphates and/or electrons between carbohydrate
intermediates and other compounds (e.g. ATP, NADH) occurs in the reactions catalyzed
by all of the following enzymes except:
A. Hexokinase
B. * Phosphohexose isomerase
C. Phosphofructokinase-1
D. Glyceraldehyde-3-phosphate dehydrogenase
E. Phosphoglycerate kinase
828.
Transketolase is an enzyme that catalyzes:
A. Transfers of three-carbon units from a ketose to an aldose.
B. Transfer of ketoses into aldoses.
C. * Transfer of xylulose-5-phosphate into ribulose-5-phosphate.
D. TPP-dependent transfer of 2-carbon units to the recipient aldose.
E. Transfer of keto groups from C-2 to C-3.
829.
Two conditions in which gluconeogenesis is increased are
A. Diabetes mellitus and atherosclerosis
B. Fed condition and thyrotoxicosis
C. * Diabetes mellitus and Starvation
D. Alcohol intake and cigarette smoking
E. Riscets and obesyti
830.
UDP-Glucose is converted to UDPGlucuronic acid by
A. ATP
B. * GTP
C. NADP+
D. NAD+
E. Glutation
831.
Value of kidney threshold for glucose:
A. 5-7 mmol/l
B. 8-10 mmol/l
C. * 10-15 mmol/l
D. 2-3 mmol/l
E. 15-20 mmol/l
832.
What chemical species activates the GLUT4 protein to transport glucose into
cells?
A. Adrenaline
B. * Insulin
C. Protein kinase A
D. PFK-2
E. None of the above
833.
When lactose is digested, it yields two monosaccharides called
A. Glucose and glucose.
B. Maltose and glucose.
C. Glucose and fructose.
D. * Glucose and galactose
E. None of the above
834.
When liver glycogen levels are inadequate to supply glucose, especially to the
brain, amino acids and glycerol are used to produce ___________ in a process called
A. Glycogen; glycogenesis
B. Glucose; gluconeogenesis
C. Lipids; lipogenesis
D. * Glucose-6-phosphate; glycogenolys
E. None of the above
835.
When the body metabolizes nutrients for energy, fats yield about _______ times
the energy as carbohydrates or proteins.
A. 1/2
B. 2
C. 4
D. * 6
E. 3
836.
Which coenzymes are reduced in both glycolysis and the Krebs' cycle?
A. FAD
B. Coenzyme A
C. Manganese
D. * NAD
E. Vitamin A
837.
Which method of the measurement of glucose in urine is widely used?
A. Gess
B. Tromer
C. Feling
D. Selivanov
E. * Altgausen
838.
Which of the below-mentioned diseases can be found by the method of sugary
loading?
A. Ishemia
B. Hepatitis
C. * Diabetes mellitus
D. Titania
E. Anemia
839.
Which of the below-mentioned processes is the source of NADPH2 in the
organism?
A. Gluconeogenesis
B. * Pentose-phosphate cycle
C. Glycolysis
D. Glycogenolysis
E. Glycogenogenesis
840.
Which of the following enzymes acts in the pentose phosphate pathway?
A. * 6-phosphogluconate dehydrogenase
B. Aldolase
C. Glycogen phosphorylase
D. Phosphofructokinase-1
E. Pyruvate kinase
841.
Which of the following generates free glucose during the enzymatic breakdown of
glycogen in skeletal muscle?
A. Phosphorylase
B. Debranching enzyme
C. * ?-1-6-amyloglucosidase
D. Amylase
E. Glucose-6-phosphatase
842.
Which of the following groups contain only water soluble vitamins?
A. A , B
B. * B, C
C. C, D
D. D, E
E. A, D
843.
Which of the following is a cofactor in the reaction catalyzed by glyceraldehyde
3-phosphate dehydrogenase?
A. ATP
B. Cu2+
C. Heme
D. * NAD+
E. NADP+
844.
Which of the following is FALSE with regards to GNG
A. Glycerol, lactate, pyruvate, alanine are precursors for GNG
B. The rate of GNG is highest post exercise
C. * GNG occurs in muscle and liver
D. Glucose 6-phosphotase by passes hexokinase
E. One of the major regulators of flux through GNG is substrate availability
845.
Which of the following is likely to be the most important in terms of regulating
hepatic glucose production?
A. Direct innervation of the liver
B. Increase in catecholamines
C. Feedforward mechanisms from the CNS
D. * Increase in glucagon to insulin ratio
E. A only
846.
Which of the following is not a precursor for gluconeogenesis?
A. Alanine
B. Glycerol
C. Oxaloacetate
D. * Acetate
E. Only B
847.
Which of the following is not a true statement?
A. Muscle glycogen is broken down enzymatically to glucose-1-phosphate
B. Elite endurance runners have a high proportion of Type I fibres in their leg
muscles
C. Liver glycogen is important in the maintenance of the blood glucose
concentration
D. * Insulin promotes glucose uptake by all tissues in the body
E. Glucagon has generally antagonistic actions to those of insulin
848.
Which of the following is true concerning glycolysis?
A. It is an aerobic process.
B. A net of 2 molecules of ATP are produced.
C. A total of 38 ATP are produced.
D. * 4 NADH are produced.
E. None of the above
849.
Which of the following processes converts lactic acid to glucose?
A. Citric acid cycle
B. Krebs cycle
C. * Cori cycle
D. None of the above.
E. All of the above
850.
Which of the following processes describes the formation of glycogen from
excess glucose in the blood?
A. Ketogenesis
B. Glycogenolysis
C. Lipogenesis
D. * Gluconeogenesis
E. Only A
851.
Which of the following processes is involved in converting amino acids into
glucose?
A. Glycogenolysis
B. Lipogenesis
C. * Gluconeogenesis
D. Transamination
E. None of the above
852.
Which of the following reaction gives lactose?
A. * UDP galactose and glucose
B. UDP glucose and galactose
C. Glucose and Galactose
D. Glucose, Galactose and UTP
E. UDP fructose and glucose
853.
Which of the following reactions is catalyzed by a transketolase in the pentose
phosphate pathway? (select a capital letter from A to E): І. Fructose-6-P +
glyceraldehyde-3-P . xylulose-5-P + erythrose-4-P II. Erythrose-4-P + fructose-6-P I
sedoheptulose-7-P + glyceraldehyde-3-P III. Sedoheptulose-7-P + glyceraldehyde-3-P I
ribose-5-P + xyulose-5-P
A. * I only
B. II and III
C. II only
D. I and III
E. I and II
854.
Which of the following reactions is unique to gluconeogenesis?
A. Lactate Pyruvate
B. Phosphoenol pyruvate pyruvate
C. * Oxaloacetate phosphoenol pyruvate
D. Glucose-6-phosphate Fructose-6-phosphate
E. None of the above
855.
Which of the following statements about glycolysis is false?
A. It results in the formation of two molecules of pyruvic acid.
B. It results in the net gain of four ATP molecules.
C. It can occur with or without oxygen present.
D. * It is an exergonic reaction.
E. Only C
856.
Which of the following statements about pyruvate kinase is true?
A. Active in both glycolysis and gluconeogenesis
B. * Activated by phosphorylation
C. Stimulated by ATP
D. Inhibited by fructose-1,6-bisphosphate
E. None of the above are true
857.
Which of the following statements about the pentose phosphate pathway is
incorrect?
A. It generates CO2 from C-1 of glucose.
B.
C.
D.
E.
It involves the conversion of an aldohexose to an aldopentose.
It is prominant in lactating mammary gland.
It is principally directed toward the generation of NADPH.
* It requires the participation of molecular oxygen.
858.
Which of the following statements is true?
A. ATP stimulates phosphofructokinase-1 and inhibits fructose-1,6-bisphosphatase.
B. AMP stimulates both phosphofructokinase-1 and fructose-1,6-bisphosphatase.
C. * AMP stimulates phosphofructokinase-1 and inhibits fructose-1,6bisphosphatase.
D. Citrate stimulates phosphofructokinase-1 and inhibits fructose-1,6bisphosphatase.
E. Citrate stimulates phosphofructokinase-1 and glucose-6-phosphatase.
859.
Which of the following steps from glycolysis is performed by a different enzyme
in gluconeogenesis?
A. Isomerase
B. * Phosphofructokinase (PFK)
C. Glyceraldehyde-3-P dehydrogenase
D. Enolase
E. Aldolase
860.
Which of the following substances are NOT stored in the body?
A. * Amino acids
B. Glycogen
C. Triglycerides
D. Cholesterol
E. None of the above
861.
Which of the following substances is produced in limited quantities in glycolysis
as a result of the metabolism of excessive amounts of alcohol (ethanol)?
A. * NADH
B. Lipids
C. Glucose
D. Glycogen
E. All of the above
862.
Which of these cofactors participates directly in most of the oxidation-reduction
reactions in the fermentation of glucose to lactate?
A. ADP
B. ATP
C. FAD/FADH2
D. Glyceraldehyde 3-phosphate
E. * NAD+/NADH
863.
Which of these does not occur for about four hours after a meal?
A. Glucose enters cells and is either used or stored as glycogen or fat.
B. * Fatty acids and glycerol combine to form fat, which when absorbed is deposited
in adipose tissue.
C. Amino acids are used in protein synthesis, some are used for energy and some are
converted to fats and carbohydrates.
D. Glycerol is converted to glucose, fatty acids are converted to acetyl-CoA, and
acetyl-CoA is used to produce ketone bodies.
E. All of the above
864.
Which one of the following is a rate limiting enzyme of gluconeogenesis?
A. Hexokinase
B. Phsophofructokinase
C. * Pyruvate carboxylase
D. Pyruvate kinase
E. Glucokinase
865.
Which one of the following is NOT a major factor in pancreatic o-cell dysfunction
in patients with type 2 diabetes mellitus?
A. Environmental factors.
B. Genetic factors.
C. Lipotoxicity.
D. Glucotoxicity.
E. * Insulin toxicity.
866.
Which one of the following would not be a characteristic of the postabsorptive
state which occurs late in the morning, late in the afternoon or early in the morning
before breakfast?
A. * Glycogen is broken down to produce glucose.
B. Amino acids are used to synthesize proteins.
C. Triglycerides in adipose tissue break down to glycerol and fatty acids
D. Lactic acid is produced and then converted to glucose in the liver.
E. None of the above
867.
Which statement is true regarding the ‘lactate/anaerobic threshold’ phenomenon?
A. An increase in ventilation is caused by an decrease in both H+ and pCO2
B. It is a poor predictor of marathon performance
C. The power output at which it occurs is decreased with endurance training
D. It is a good indicator of the onset of anaerobic metabolism
E. * Theoretically, a sharp increase in blood lactate, ventilation, and VCO2/VO2 all
occur at the lactate threshold
868.
Which substance causes muscles to ache during strenuous exercise?
A. Pyruvic acid
B. Lactose dehydrogenase
C. Lactate ion
D. * Lactic acid
E. None of the above
869.
Which two factors regarding sports drinks affect gastric emptying the most:
A. * Volume, amount of glucose
B. Temperature; carbonation
C. Volume; temperature
D. Amount of glucose; carbonation
E. None of the above
870.
Cerebonic acid is present in
A. Triglycerides
B. * Cerebrosides
C. Esterified cholestrol
D. Sphingomyelin
E. Glycerophospholipids
871.
Energetic function in the organism play the following lipids, except:
A. tryacylglycerol
B. saturated fatty acids
C. diacylglycerol
D. monounsaturated fatty acids
E. * cholesterol
872.
In glycerophospholipids, a polyunsaturated fatty acid is commonly attached to
which of the following carbon atom of glycerol?
A. Carbon 1
B. * Carbon 2
C. Both (A) and (B)
D. Carbon 3
E. None of these
873.
The highest phospholipids content is found in
A. Chylomicrons
B. VLDL
C. LDL
D. * HDL
E. B and D
874.
Which of the following is not essential fatty acid?
A. * Oleic acid
B. Linoleic acid
C. Arachidonic acid
D. Linolenic acid
E. Both (A) and (B)
875.
_____ are the simplest lipids but they may be a part of or a source of many
complex lipids.
A. Triglycerols
B. Carbohydrates
C. Terpenes
D. * Fatty acids
E. Waxes
876.
1 molecule of palmitic acid on total oxidation to CO2 will yield molecules of ATP
(as high energy bonds):
A. * 129
B. 154
C. 83
D. 25
E. 229
877.
9 indicates a double bond between carbon atoms of the fatty acids:
A. 8 and 9
B. * 9 and 10
C. 9 and 11
D. 9 and 12
E. None of the above
878.
A digestive secretion that does not contain any digestive enzyme is
A. Saliva
B. Gastric juice
C. Pancreatic juice
D. * Bile
E. A and D
879.
A fatty acid which is not synthesized in human body and has to be supplied in the
diet:
A. Palmitic acid
B. Oleic acid
C. * Linoleic acid
D. Stearic acid
E. All of these
880.
A reserve fats in the fat depot mainly are:
A. * tryacylglycerols
B. phospholipids
C. cholesterol
D. fatty acids
E. glycolipids
881.
Acetyl CoA carboxylase regulates fatty acid synthesis by which of the following
mechanism?
A. Allosteric regulation
B. Covalent modification
C. Induction and repression
D. * All of these
E. None of these
882.
acids into mitochondria
A. It can be synthesized in the human body
B. It can be synthesized from methionine and lysine
C. * It is required for transport of short chain fatty
D. Its deficiency can occur due to haemodialysis
E. A and B
883.
After entering cytosol, free fatty acids are bound to
A. Albumin
B. Globulin
C. * Z-protein
D. All of these
E. None of these
884.
All of the following occur during synthesis of ether lipids except:
A. Esterification of an acyl group from fatty acyl CoA to dihydroxyacetone
phosphate
B. Displacement of 1-acyldihydroxyacetone phosphate by a fatty alcohol
C. * Oxidation of the keto group of 1-acyldihydroxyacetone by NADPH
D. Esterification of 1-alkylglycero-3-phosphate to produce 1-alkyl-2-acylglycero-3phosphate
E. None of the above
885.
All the following can be oxidized by ?-oxidation except
A. Palmitic acid
B. * Phytanic acid
C. Linoleic acid
D. Fatty acids having an odd number of carbon atoms
E. B and D
886.
All the following have 18 carbon atoms except
A. Linoleic acid
B. Linolenic acid
C. * Arachidonic acid
D. Stearic acid
E. B and C only
887.
All the following statements about brown adipose tissue are true except
A. It is rich in cytochromes
B. It oxidizes glucose and fatty acids
C. * Oxidation and phosphorylation are tightly coupled in it
D. Dinitrophenol has no effect on it
E. C and D
888.
Amphiphatic lipids are
A. Hydrophilic
B. Hydrophobic
C. * Both (A) and (B)
D. Lipophilic
E. All of these
889.
Arachidonic acid contains the number of double bonds:
A. 2
B. 3
C. * 4
D. 5
E. 1
890.
Bile acids are metabolic products of :
A. * cholesterol
B. phospholipids
C. tryglycerins
D. glycogen
E. glycolipids
891.
Bile is produced by
A. * Liver
B. Gall-bladder
C. Pancreas
D. Intestine
E. All of the above
892.
Biological functions of lipids include
A. Source of energy
B. Insulating material
C. Maintenance of cellular integrity
D. * All of these
E. A and C only
893.
C22 and C24, fatty acids required for the synthesis of sphingolipids in brain are
formed by
A. De novo synthesis
B. * Microsomal chain elongation
C. Mitochondrial chain elongation
D. All of these
E. A and B
894.
Carnitine is required for the transport of
A. Triglycerides out of liver
B. Triglycerides into mitochondria
C. Short chain fatty acids into mitochondria
D. * Long chain fatty acids into mitochondria
E. C and D
895.
Cephalin consists of
A. Glycerol, fatty acids, phosphoric acid and choline
B. * Glycerol, fatty acids, phosphoric acid and ethanolamine
C. Glycerol, fatty acids, phosphoric acid and inositol
D. Glycerol, fatty acids, phosphoric acid and Serine
E. Glycerol, fatty acids, hydrochloric acid and ethanolamine
896.
Ceramide is a precursor to which of the following compounds?
A. Phosphatidyl serine
B. * Sphingomyelin
C. Phosphatidyl glycerol
D. Phosphatidyl choline
E. Phosphatidyl ethanolamine
897.
Cerebrosides are composed of
A. Sphingosine, fatty acids, glycerol and phosphoric acid
B.
C.
D.
E.
* Sphingosine, fatty acids, galactose
Glycerol, fatty acids, galactose
Glycerol, fatty acids, galactose, sphingol
Both (A) and (B)
898.
Current concepts concerning the intestinal absorption of triacylglycerols are that
A. They must be completely hydrolysed before the constituent fatty acids can be
absorbed
B. * They are hydrolysed partially and the material absorbed consists of free fatty
acids, mono and diacyl glycerols and unchanged triacyl glycerols
C. Fatty acids with less than 10 carbon atoms are absorbed about equally via lymph
and via portal blood
D. In the absence of bile the hydrolysis of triacyl glycerols is absorbed
E. B and D
899.
Depot fats of mammalian cells comprise mostly of
A. Cholesterol
B. Cholesterol esters
C. * Triacyl glycerol
D. Phospholipids
E. All of these
900.
Dietary triacylglycerols are digested as a result of
A. Lipase action
B. Bile salts
C. Micelle formation
D. Diffusion and absorption by intestinal cells
E. * All of the above
901.
Dipalmitoyl lecithin acts as
A. Platelet activating factor
B. Second messenger for hormones
C. * Lung surfactant
D. Anti-ketogenic compound
E. All of the above
902.
During each cycle of ? -oxidation
A. One carbon atom is removed from the carboxyl end of the fatty acid
B. One carbon atom is removed from the methyl end of the fatty acid
C. * Two carbon atoms are removed from the carboxyl end of the fatty acid
D. Two carbon atoms are removed from the methyl end of the fatty acid
E. Three carbon atoms are removed from the carboxyl end of the fatty acid
903.
During each cycle of ?-oxidation of fatty acid, all the following compounds are
generated except
A. NADH
B. * H2O
C. FAD
D. Acyl CoA
E. Both B and C
904.
During fatty acid metabolism in humans, coenzyme A (CoA) is different from
acyl carrier protein (ACP) in which one of the following ways?
A. Binding of malonic acid with a phosphopantetheine
B. Binding of fatty acids
C. * Function in fatty acid oxidation
D. Function in the cytosol
E. Function in fatty acid synthesis
905.
During the fed state, which of the following occur(s)?
A.
B.
C.
D.
E.
906.
A.
B.
C.
D.
E.
907.
A.
B.
C.
D.
E.
908.
A.
B.
C.
D.
E.
909.
A.
B.
C.
D.
E.
910.
A.
B.
C.
D.
E.
911.
A.
B.
C.
D.
E.
912.
A.
B.
C.
D.
E.
913.
A.
B.
C.
D.
Insulin inhibition of stored triacylglycerols' hydrolysis
Insulin stimulation of malonyl CoA formation
Allosteric inhibition of carnitine acyltransferase I
* All of the above
A and C only
During the fed state, which of the following occur(s)?
Insulin inhibition of stored triacylglycerols' hydrolysis
Insulin stimulation of malonyl CoA formation
Allosteric inhibition of carnitine acyltransferase I
* All of the above
A and C only
Fatty acids are activated to acyl CoA by the enzyme thiokinase:
NAD+
NADP+
* CoA
FAD+
CoQ
Fatty acids are oxidized by
??-oxidation
??-oxidation
??-oxidation
* All of these
None of these
Fatty acids are oxidized in the ___________.
* mitochondrial matrix
cytosol
endoplasmic reticulum
mitochondrial inner membrane space
nucleus
Fatty acids having chain length of 10 carbon atoms enter the
* Portal ciruclation
Lacteals
Systemic circulation
Colon
Both (A) and (c)
Fatty acids required in the diet of mammals are called
Important
Dietary
Saturated
* Essential
Esters
Fatty liver may be caused by
Deficiency of methionine
Puromycin
Chronic alcoholism
* All of these
A and C
Fatty liver may be prevented by all of the following except
Choline
Betaine
Methionine
* Ethionine
E. A and C
914.
Fluidity of membranes is increased by the following constituent except
A. * Polyunsaturated fatty acids
B. Saturated fatty acids
C. Integral proteins
D. Cholesterol
915.
For every 2 mol of free glycerol released by lipolysis of triacylglycerides in
adipose tissue
A. 2 mol of triacylglycerides is released
B. 2 mol of free fatty acids is released
C. * 1 mol of glucose can be synthesized in gluconeogenesis
D. 1 mol of triacylglyceride is released
E. 3 mol of acyl CoA is produced
916.
For extramitochondrial fatty acid synthesis, acetyl CoA may be obtained from
A. * Citrate
B. Isocitrate
C. Oxaloacetate
D. Succinate
E. Succsinil-CoA
917.
For the activation of long chain fatty acids the enzyme thiokinase requires the
cofactor:
A. Mg++
B. * Ca++
C. Mn++
D. K+
E. Fe++
918.
Free fatty acids are transported in the blood
A. * Combined with albumin
B. Combined with fatty acid binding protein
C. Combined with ??-lipoprotein
D. In unbound free salts
E. Combined with ??-lipoprotein
919.
Glycerol is transformed into active form with the enzyme:
A. phosphatidate phosphatase
B. * glycerol kinase
C. glycerol phosphate dehydrogenase
D. glycerol phosphate acyltransferase
E. diglyceride-acyl-transferase
920.
Glycerol released from adipose tissue by hydrolysis of triglycerides is mainly
A. * Taken up by liver
B. Taken up by extrahepatic tissues
C. Reutilised in adipose tissue
D. Excreted from the body
E. All of the above
921.
Glycosphingolipids are a combination of
A. * Ceramide with one or more sugar residues
B. Glycerol with galactose
C. Sphingosine with galactose
D. Sphingosine with phosphoric acid
E. None of the above
922.
Hepatic lipogenesis is stimulated by:
A. cAMP
B.
C.
D.
E.
Glucagon
Epinephrine
* Insulin
B and D
923.
Hepatoenteral circulation of bile acids has such aim as:
A. fats resynthesis
B. formation of chylomicrons
C. * economical usage of bile acids
D. cholesterol absorption
E. glycerol absorption
924.
Hepatoenteral circulation of bile acids is important for:
A. fat resynthesis
B. formation of chylomicrons
C. * economical usage of bile acids
D. cholesterol absorption
E. glycerin absorption
925.
Higher alcohol present in waxes is
A. Benzyl
B. Methyl
C. Ethyl
D. * Cetyl
E. None of the above
926.
How many cycles of ? -oxidation are required to completely process a saturated
C18 fatty acid?
A. 6
B. * 8
C. 9
D. 18
E. 10
927.
How many cycles of ?-oxidation are required to completely process a saturated
C18 fatty acid?
A. 6
B. * 8
C. 9
D. 18
E. 7
928.
How many enzymes are there in the palmitate synthase multienzyme complex?
A. 5
B. 2
C. 3
D. 10
E. * 7
929.
How many QH2 and NADH are produced by one round of the ?-oxidation
pathway?
A. * 1 each
B. 1 QH2 and 2 NADH
C. 2 each
D. 2 QH2 and 1 NADH
E. all of the above
930.
Human desaturase enzyme system cannot introduce a double bond in a fatty acid
beyond
A. * Carbon 9
B.
C.
D.
E.
Carbon 6
Carbon 5
Carbon 3
Carbon 7
931.
Hydrolysis of fats by alkali is called
A. Saponification number
B. * Saponification
C. Both (A) and (B)
D. Lipolysis
E. None of these
932.
If the carbonyl carbon of a fatty acyl CoA molecule with a C10 chain is labeled
with 14C, how many rounds of ?-oxidation are required to produce a radioactively
labeled acetyl CoA?
A. * one
B. two
C. four
D. five
E. six
933.
In adipose tissue, glycerol-3-phosphate required for the synthesis of triglycerides
comes mainly from
A. Hydrolysis of pre-existing triglycerides
B. Hydrolysis of phospholipids
C. * Dihydroxyacetone phosphate formed in.glycolysis
D. Free glycerol
E. All of the above
934.
In cephalin, choline is replaced by
A. Serine
B. * Ethanolamine
C. Betaine
D. Sphingosine
E. Both B and C
935.
In humans, a dietary essential fatty acid is
A. Palmitic acid
B. Stearic acid
C. Oleic acid
D. * Linoleic acid
E. All of the above
936.
In humans, the formation of the fatty acid C-18-?9,?12 can be derived from which
of the following?
A. C-18 cis-?9
B. C-18 cis- ? 6
C. C-18
D. C-16 cis- ? 6, ? 9
E. * C-18 cis- ? 9, ? 12
937.
In mammals, the major fat in adipose tissues is
A. Phospholipid
B. Cholesterol
C. Sphingolipids
D. * Triacylglycerol
E. All of the above
938.
In neutral fats, the unsaponificable matter includes
A. * Hydrocarbons
B.
C.
D.
E.
Triacylglycerol
Phospholipids
Cholsesterol
Fatty acids
939.
In oxidation of fatty acids with odd number of carbon atoms propionyl-CoA is
transformed to:
A. malonyl-CoA
B. * succinyl-CoA
C. enoil-CoA
D. butyryl-CoA
E. acetacetyl-CoA
940.
In synthesis of Triglyceride from Glycerol 3-phosphate and acetyl CoA, the first
intermediate formed is
A. ?-diacyl glycerol
B. Acyl carnitine
C. Monoacyl glycerol
D. * Phosphatidic acid
E. None of the above
941.
In the construction of liquid lipids prevail:
A. saturated fatty acids
B. * unsaturated fatty acids
C. dicarboxylic acids
D. keto acid
E. hydroxide acids
942.
In the extra mitochondrial synthesis of fatty acids, CO2 is utilized
A. To keep the system anaerobic and prevent regeneration of acetyl CoA
B. In the conversion of malonyl to CoA hydroxybutyryl CoA
C. * In the conversion of acetyl CoA to malonyl CoA
D. In the formation of acetyl CoA from 1 carbon intermediates
943.
In ??-oxidation of fatty acids which of the following are utilized as co-enzymes?
A. NAD+ and NADP+
B. FAD H2 and NADH + H+
C. FAD and FMN
D. * FAD and NAD+
E. All of these
944.
Isoprenoids are lipids which do not contain nor are derived from fatty acids and
include
A. Steroids
B. Waxes
C. Terpenes
D. * a and c
E. a, b, and c
945.
Lecithin belongs to:
A. neutral fat
B. * phospholipids
C. waxes
D. steroids
E. glycolipids
946.
Lecithins are composed of
A. * Glycerol + Fatty acids + Phosphoric acid + Choline
B. Glycerol + Fatty acids + Phosphoric acid + Ethanolamine
C. Glycerol + Fatty acids + Phosphoric acid + Serine
D. Glycerol + Fatty acids + Phosphoric acid + Beaine
E. All of these
947.
Like plasmologens, sphingolipids are found in relative abundance in
A. Bacteria
B. Plant cells
C. * Nerve cells
D. Intestinal cells
E. All of the above
948.
Lipase can act only at pH:
A. 2.5–4
B. 3.5–5
C. 4 to 5
D. * 5–7
E. 8-9
949.
Lipase present in the stomach cannot hydrolyze fats owing to
A. Alkalinity
B. Acidity
C. * High acidity
D. Neutrality
E. None of the above
950.
Lipid stores are mainly present in
A. Liver
B. Brain
C. Muscles
D. * Adipose tissue
E. A and D
951.
Lipids are stored in the body mainly in the form of
A. Phospholipids
B. Glycolipids
C. * Triglycerides
D. Fatty acids
E. Cholesterol
952.
Lipids have the following properties:
A. Insoluble in water and soluble in fat solvent
B. High energy content
C. Structural component of cell membrane
D. * All of these
E. A and C only
953.
Lipids may be either hydrophobic or
A. Hydrophilic
B. Organic
C. Inorganic
D. * Amphipathic
E. Soluble in polar solvents
954.
Lisophospholipids, formed after action of phospholipase A2, have the following
feature:
A. activate lipase
B. * hemolytic
C. form conjugates with bile acids
D. participate in phospholipids resynthesis
E. accompany absorption of fatty acids
955.
Long chain acyl CoA penetrates mitochondria in the presence of
A.
B.
C.
D.
E.
956.
A.
B.
C.
D.
E.
957.
A.
B.
C.
D.
E.
958.
A.
B.
C.
D.
E.
959.
A.
B.
C.
D.
E.
960.
A.
B.
C.
D.
E.
961.
A.
B.
C.
D.
E.
962.
A.
B.
C.
D.
E.
963.
A.
B.
C.
D.
Palmitate
* Carnitine
Sorbitol
DNP
cAMP
Long chain fatty acids are first activated to acetyl-CoA in
* Cytosol
Microsomes
Nucleus
Mitochondria
EPR
Long chain fatty acids are first activated to acyl CoA in the
* Cytosol
Mitochodria
Ribosomes
Microsome
EPR
Long chain fatty acids penetrate the inner mitochondrial membrane
Freely
As acyl-CoA derivative
* As carnitine derivative
Requiring Na dependent carrier
As lipoproteins
Lysolecithin is formed from lecithin by removal of
Fatty acid from position 1
* Fatty acid from position 2
Phosphorylcholine
Choline
None of these
Malonyl-CoA reacts with the central
* —SH group
—NH2 group
—COOH group
—CH2OH group
C and D
Maximum energy produced by
* Fats
Carbohydrates
Proteins
Nucleic acids
All of these
Mitochondrial lipogenesis requires
bicarbonate
biotin
acetyl CoA carboxylase
* NADPH
Both (A) and (B)
Mitochondrial membrane is permeable to
* Short chain fatty acids
Medium chain fatty acids
Long chain fatty acids
All of these
E. A and B
964.
Mitochondrial thiokinase acts on
A. * Short chain of fatty acids
B. Medium chain fatty acids
C. Long chain fatty acids
D. A and B
E. All of these
965.
Most animal tissues contain appreciable amounts of lipid, when in the form of
depot fat it consists largely of
A. Cholesterol ester
B. Phosphatides
C. Chylomicrons
D. * Triacylglycerol
966.
Most of the reducing equivalents utilized for synthesis of fatty acids can be
generated from
A. * The pentose phosphate pathway
B. Glycolysis
C. The citric acid cycle
D. Mitochondrial malate dehydrogenase
E. Citrate lyase
967.
NADPH required for fatty acid synthesis can come from
A. Pentose phosphate shunt
B. Oxidative decarboxylation of malate
C. Extramitochondrial oxidation of isocitrate
D. * All of these
E. A and B
968.
Net ATP generation on complete oxidation of stearic acid is
A. 129
B. 131
C. * 146
D. 148
E. 120
969.
Net energy generation on complete oxidation of linoleic acid is
A. 148 ATP equivalents
B. 146 ATP equivalents
C. 144 ATP equivalents
D. * 142 ATP equivalents
E. 138 ATP equivalents
970.
Net generation of energy on complete oxidation of palmitic acid is
A. 129 ATP equivalents
B. 131 ATP equivalents
C. 146 ATP equivalents
D. * 148 ATP equivalents
E. 118 ATP equivalents
971.
Net generation of energy on complete oxidation of a 17-carbon fatty acid is
A. Equal to the energy generation from a 16-carbon fatty acid
B. Equal to the energy generation from an 18-carbon fatty acid
C. * Less than the energy generation from a 16-carbon fatty acid
D. In between the energy generation from a16-carbon fatty acid and an 18-carbon
fatty acid
E. None of the above
972.
Niemann-Pick disease results from deficiency of
A.
B.
C.
D.
E.
Ceramidase
* Sphingomyelinase
Arylsulphatase A
Hexosaminidase A
Lipase
973.
Normal fat content of liver is about _______ gms %.
A. * 5
B. 8
C. 10
D. 15
E. 55
974.
Number of carbon atoms in cholesterol is
A. 17
B. 19
C. * 27
D. 30
E. 25
975.
One functional sub-unit of multi-enzyme complex for de novo synthesis of fatty
acids contains
A. One —SH group
B. * Two —SH groups
C. Three —SH groups
D. Four —SH groups
E. Five —SH groups
976.
Oxidation of fatty acids occurs
A. In the cytosol
B. * In the matrix of mitochondria
C. On inner mitochondrial membrane
D. On the microsomes
E. In the EPR
977.
Pancreatic lipase converts triacylglycerols into
A. 2, 3-Diacylglycerol
B. 1-Monoacylglycerol
C. * 2-Monoacylglycerol
D. 3-Monoacylglycerol
E. B and C only
978.
Pancreatic lipase requires for its activity:
A. Co-lipase
B. Bile salts
C. Phospholipids
D. * A and b only
E. All of these
979.
Pancreatic lipose is an enzyme which hydrolyzes fats. It acts as a/an
A. peptidase
B. * hydrolase
C. carbohydrates
D. dehydrogenase
E. None of the above
980.
Phosphatidic acid on hydrolysis yields
A. Glycerol, fatty acids, phosphoric acid, choline
B. * Glycerol, fatty acids, phosphoric acid
C. Glycerol, fatty acids, phosphoric acid, glucose
D. Sphingol, fatty acids, phosphoric acid
E. Both (A) and (B)
981.
Phospholipase A2 is an enzyme which removes a fatty acid residue from lecithin
to form
A. Lecithin fragments
B. Phosphotidic acid
C. Glyceryl phosphate
D. * Lysolecithin
E. Both A and D
982.
Phospholipids are important cell membrane components because
A. They have glycerol
B. They can form bilayers in water
C. * They have both polar and non polar potions
D. They combine covalently with proteins
E. All of these
983.
Phospholipids form bilipid layer of cellular membranes as a result of:
A. hydrophilic features
B. hydrophobic features
C. construction complexity
D. * amphiphilic features
E. molecules stability
984.
Phospholipids help the oxidation of
A. Glycerol
B. * Fatty acids
C. Glycerophosphates
D. Glucose
E. None of these
985.
Phospholipids in the organism perform such functions, except:
A. are a part of cellular membranes
B. * have atherosclerotic properties
C. have antiatherosclerotic activity
D. are lipotropic factors
E. participate in the formation of blood lipoproteins
986.
Plasma becomes milky
A. Due to high level of HDL
B. Due to high level of LDL
C. During fasting
D. * After a meal
E. All of the above
987.
Polar heads of glycerophospholipids may be
A. + charged
B. - charged
C. Neutral
D. A mixture of + and - charges, but not neutral
E. * All of the above
988.
Properties of acetyl CoA-carboxylase include:
A. Activation by fatty acyl CoA
B. Phosphorylation and inactivation by glucagon in adipocytes
C. Inactivation of its phosphorylation by epinephrine in the liver
D. All of the above
E. * None of the above
989.
Propionyl CoA formed oxidation of fatty acids having an odd number of carbon
atoms is converted into
A. Acetyl CoA
B. Acetoacetyl CoA
C. * D-Methylmalonyl CoA
D. Butyryl CoA
E. None of the above
990.
Propionyl CoA is formed on oxidation of
A. Monounsaturated fatty acids
B. Polyunsaturated fatty acids
C. * Fatty acids with odd number of carbon atoms
D. All of these
E. None of these
991.
Refsum’s disease results from a defect in the following pathway except
A. * Alpha-oxidation of fatty acids
B. Beta-oxidation of fatty acids
C. Gamma-oxidation of fatty acids
D. Omega-oxidation of fatty acids
E. None of these
992.
Release of free fatty acids from adipose tissue is increased by all of the following
except
A. Glucagon
B. Epinephrine
C. Growth hormone
D. * Insulin
E. C and D
993.
Reserve fat in the fat depot mainly belong to:
A. * tryacylglycerols
B. phospholipids
C. cholesterol
D. fatty acids
E. glycolipids
994.
Saliva contains a lipase which acts on triglycerides having
A. * Short chain fatty acids
B. Medium chain fatty acids
C. Long chain fatty acids
D. All of these
E. A and B only
995.
Salivary lipase converts dietary triglycerides into
A. * Diglycerides and fatty acids
B. Monoglycerides and fatty acids
C. Glycerol and fatty acids
D. All of these
E. A and b only
996.
Salivary lipase hydrolyses the ester bond at
A. Position 1 of triglycerides
B. Position 2 of triglycerides
C. * Position 3 of triglycerides
D. All of these
E. A and b only
997.
Salivary lipase is secreted by
A. Parotid glands
B.
C.
D.
E.
Submandibular glands
* Dorsal surface of tongue
None of these
A and B
998.
Sphingomyelins:
A. * Phospholipids
B. Complex proteins
C. Nitrolipids
D. Alcohols
E. None of these
999.
Sphingosine is synthesized from
A. Palmitoyl CoA and Choline
B. Palmitoyl CoA and ethanolamine
C. * Palmitoyl CoA and serine
D. Acetyl CoA and choline
E. None of above
1000.
Splitting off acetyl-CoA in the final reaction of ?-oxidation of fatty acids is
performed by the enzyme:
A. dehydrogenase
B. enolase
C. hydrase
D. lipase
E. * thiolase (acetyl-CoA-acyltransferase)
1001.
Sterols are steroids which have
A. A hydroxyl group at position C-17
B. * A hydroxyl group at position C-3
C. The ability to accumulate as plaques in blood vessels
D. 5 fused rings instead of 4 fused rings
E. Hydroxyl groups at both position C-3 and C-17
1002.
The ‘free fatty acids’ (FFA) of plasma:
A. metabolically inert
B. mainly bound to ? -lipoproteins
C. stored in the fat
D. * mainly bound to serum albumin
E. All of the above
1003.
The acids which are irreplaceable (essential) for human organism:
A. lipoic acid, stearic acid, palmitic acid
B. oleic acid, linoleic acid, linolenic acid
C. palmitic acid, stearic acid, arachidonic acid
D. * arachidonic acid, linolenic acid, linoleic acid
E. butyric acid, oleic acid, linolenic acid
1004.
The amount of total lipids in blood is:
A. * 3-8 g/l
B. 5-10 g/l
C. 2-3 g/l
D. 15-20 g/l
E. 7-12 g/l
1005.
The bile acids in bile are in conjugated condition with:
A. cholesterol
B. bilirubin
C. glycine and alanine
D. * glycine and taurine
E. taurine and valine
1006.
The carbon chain of fatty acids is shortened by 2 carbon atoms at a time. This
involves successive reactions catalysed by 4-enzymes. These act the following order:
A. Acetyl CoA dehydrogenase, ?-OH acyl CoA dehydrogenase, enoyl hydrase,
thiolose
B. * Acyl CoA dehydrogenase, thiolase, enoyl hydrase, ?-OH acyl CoA
dehydrogenase
C. Acyl CoA dehydrogenase, thiolose, enoyl hydrase, ?-OH acyl CoA
dehydrogenase
D. Enoyl hydrase, ?-OH acyl CoA dehydrogenase,acyl CoA dehydrogenase, thiolose
E. None of the above
1007.
The citrate transport system is responsible for:
A. * Transporting from the mitochondrion to the cytosol.
B. Generating cytosolic NADPH from cytosolic NADP+.
C. Both a and b.
D. None of the above.
E. Transporting from the cytosol to the mitochondrion.
1008.
The citrate transport system is responsible for:
A. Transporting acetyl CoA from the mitochondrion to the cytosol.
B. Generating cytosolic NADPH from cytosolic NADP+.
C. * Both a and b.
D. Generating cytosolic FADH2.
E. None of the above.
1009.
The common precursor for the synthesis of triacylglycerols, phosphatidylcholine
and phosphatidyletanolamine is:
A. choline
B. CDP-choline
C. * 1,2-diacylglycerol
D. none of the above
E. citrate
1010.
The common precursor for the synthesis of triacylglycerols, phosphatidylcholine
and phosphatidyletanolamine is:
A. choline
B. CDP-choline
C. * 1,2-diacylglycerol
D. none of the above
E. citrate
1011.
The conversion of the fatty acid palmitate (C16) to carbon dioxide via ?-oxidation,
the citric acid cycle and oxidative phosphorylation yield approximately ______ ATP
equivalents.
A. 3
B. 32
C. * 106
D. 800
E. 48
1012.
The desaturation and chain elongation system of polyunsaturated fatty acids are
greatly diminished in the absence of
A. * Insulin
B. Glycagon
C. Epinephrine
D. Thyroxine
E. C and A
1013.
The elongation and desaturation of fatty acids take place:
A. * in the cytoplasm
B. in the matrix of mitochondria
C. in the inner membranes of mitochondria
D. in the endoplasmic reticulum
E. in the nucleus
1014.
The elongation of fatty acids occurs in which of the diagrammatic structures
shown below?
A. Structure A
B. Structure B
C. * Structure C
D. Structure D
E. Structure E
1015.
The end product of cytosol fatty acid synthetase in humans is
A. Oleic acid
B. Arachidonic acid
C. Linoleic acid
D. * Palmitic acid
E. Palmitoleic acid
1016.
The energy yield from complete oxidation of products generated by second
reaction cycle of ?-oxidation of palmitoyl CoA will be
A. 5 ATP
B. 12 ATP
C. 17 ATP
D. * 34 ATP
E. 14 ATP
1017.
The enzyme acyl-CoA synthase catalyses the conversion of a fatty acid of an
active fatty acid in the presence of
A. AMP
B. ADP
C. * ATP
D. GTP
E. GDP
1018.
The enzymes of ? -oxidation are found in
A. * Mitochondria
B. Cytosol
C. Golgi apparatus
D. Nucleus
E. EPR
1019.
The fatty acid synthase complex of mammals
A. Is a dimer of unsimilar subunits
B. Is composed of seven different proteins
C. Dissociates into eight different proteins
D. Catalyzes eight different enzymatic steps
E. * Is composed of covalently linked enzymes
1020.
The fatty acids containing even number and odd number of carbon atoms as well
as the unsaturated fatty acids are oxidized by
A. ??-oxidation
B. * ??-oxidation
C. ??-oxidation
D. All of these
E. None of these
1021.
The first oxidation in the ? -oxidation of saturated fatty acids is catalyzed by
___________________ and is the conversion of____________________:
A. ? -hydroxyacyl-CoA dehydrogenase; a primary alcohol to an aldehyde.
B. * acyl-CoA dehydrogenase; a saturated to an unsaturated carbon-carbon bond.
C. acyl-CoA dehydrogenase; a secondary alcohol to a ketone.
D. acyl-CoA dehydrogenase; an aldehyde to a ketone.
E. acyl-CoA dehydrogenase; an alcohol to a ketone.
1022.
The first stage of acyl-CoA dehydrogenating in mitochondria causes the formation
of:
A. ?-keto-acyl-CoA
B. acetyl-CoA
C. ?-oxyacyl-CoA
D. * enoil-CoA
E. acylcarnitine
1023.
The formation of lisophospholipids in the intestine is caused by the action of:
A. * phospholipase A1
B. phospholipase A2
C. phospholipase C
D. phospholipase D
E. phospholipase B
1024.
The function of pentose-phosphate cycle in the synthesis of fatty acids and
cholesterol is the following:
A. main energy source
B. source of acetyl-CoA
C. source of malonyl-CoA
D. * source of NADPH2
E. source of NADH2
1025.
The hormone, that depresses the lipolysis in the fat tissue:
A. * insulin
B. epinephrine
C. glucagon
D. thyroxin
E. adrenocorticotropin
1026.
The importance of phospholipids as constituent of cell membrane is because they
possess
A. Fatty acids
B. * Both polar and nonpolar groups
C. Glycerol
D. Phosphoric acid
E. All of the above
1027.
The largest lipoproteins are the __________.
A. * chylomicrons
B. VLDLs
C. LDLs
D. HDLs
E. none of the above.
1028.
The level of free fatty acids in plasma is increased by
A. Insulin
B. * Caffeine
C. Glucose
D. Niacin
E. All of the above
1029.
The main function of the bile salts is to __________.
A. * emulsify lipids in the intestin
B. act as counterions for the ionized forms of lipids
C. cleave the ester bonds in triacylglycerols to release free fatty acids
D. form the surface layer of chylomicrons
E. none of the above.
1030.
The main function of the bile salts is to __________.
A. * transport lipids to the intestinal wall
B. act as counterions for the ionized forms of lipids
C. cleave the ester bonds in triacylglycerols to release free fatty acids
D. form the surface layer of chylomicrons
E. all of the above
1031.
The main sources of NADPH for fatty acid biosynthesis is:
A. TCA cycle
B. oxidative phosphorylation
C. * the pentose phosphate pathway
D. glycolysis
E. All of the above.
1032.
The major lipid in chylomicrons is
A. * Triglycerides
B. Phospholipids
C. Cholesterol
D. Free fatty acids
E. A and B
1033.
The major storage form of lipids is
A. Esterified cholesterol
B. Glycerophospholipids
C. * Triglycerides
D. Sphingolipids
E. B and C only
1034.
The maximum number of double bonds present in essential fatty acid is
A. 1
B. 2
C. 3
D. * 4
E. 7
1035.
The nitrogenous base in lecithin is
A. Ethanolamine
B. * Choline
C. Serine
D. Betaine
E. None of above
1036.
?The oxidation of glycerol in aerobic conditions to CO2 and H2O causes the
formation of :
A. 9 ATP molucules
B. 1 ATP molucules
C. 3 ATP molucules
D. * 22 ATP molucules
E. 15 ATP molucules
1037.
The product of lipids digestion are the following, except:
A. glycerol
B. * serine
C. phosphoric acid
D. fatty acids
E. methionine
1038.
The rate of fatty acid oxidation is increased by
A. * Phospholipids
B. Glycolipids
C. Aminolipids
D. All of these
E. A and B
1039.
The reaction, Palmitoyl-ACP--->Palmitate + HS-ACP proceeds via which of the
following enzymes?
A. * Thioesterase
B. Ketoacyl-ACP synthase
C. Transacylase
D. None of the above
E. Carboxylase
1040.
The reaction, Palmitoyl-ACP--->Palmitate + HS-ACP proceeds via which of the
following enzymes?
A. * Thioesterase
B. Ketoacyl-ACP synthase
C. Transacylase
D. All of the above
E. None of the above
1041.
The substrate for fatty acids synthesis is:
A. * acetyl-CoA
B. acyl-CoA
C. butiryl-CoA
D. propionil-CoA
E. succinyl-CoA
1042.
The triacyl glycerol present in plasma lipoproteins are hydrolyzed by
A. Linqual lipase
B. Pancreatic lipase
C. Colipase
D. * Lipoprotein lipase
E. Both B and D
1043.
There are four steps in the ?-oxidation pathway. Some reaction types are listed
below. Give the proper reaction types in the order that they occur in the ?-oxidation
pathway. 1. condensation 2. oxidation 3. reduction 4. thiolysis 5. hydration 6.
phosphorylation 7. rearrangement
A. 1,7,2,2
B. 6,3,4,2
C. 1,2,3,5
D. * 1,5,1,4
E. 1,3,1,4
1044.
Triacyl glycerol lipase of fat tissue is activated by:
A. adenosine triphosphate
B. guanosine triphosphate
C. adenosine diphosphate
D. * cyclic adenosine monophosphate
E. guanosine diphosphate
1045.
Triacylglycerols are not found in cell membranes because they are
A. Amphipathic
B.
C.
D.
E.
1046.
A.
B.
C.
D.
E.
1047.
A.
B.
C.
D.
E.
1048.
A.
B.
C.
D.
E.
1049.
A.
B.
C.
D.
E.
1050.
A.
B.
C.
D.
E.
1051.
A.
B.
C.
D.
E.
1052.
A.
B.
C.
D.
E.
1053.
A.
B.
C.
D.
* Not amphipathic
Not abundant in cells
a and c
b and c
Triacylglycerols cannot form lipid bilayers because they
Have hydrophobic tails
* Do not have polar heads
Cannot associate with cholesterol
Have polar heads
Cannot engage in hydrophobic interactions
Triglycerides are
Heavier than water
Major constituents of membranes
* Non-polar
Hydrophilic
C and D only
Tryacylglycerollipase of fatty tissue is activated by:
adenosine triphosphate
guanosine triphosphate
adenosine diphosphate
* cyclic adenosine monophosphate
guanosine diphosphate
Waxes contain higher alcohols named as
Methyl
Ethyl
Phytyl
* Cetyl
None of the above
What is the major role of phospholipase A2?
To cleave the phosphate group from phospholipids.
To phosphorylate the enzyme enoyl-CoA.
* To hydrolyze an ester bond in glycerophospholipids to form
lysophosphoglyceride.
To transport glycerophospholipids in the blood.
none of the above
What is the sub cellular site for the ?- oxidation of fatty acids?
Nucleus
* Mitochondria
Lysosome
Cytosol
All of the above
Where the resynthesis of lipids, proper for a human organism, takes place?
in the liver
in the kidney
in the muscles
* in the intestinal epithelium
in the spleen
Which dietary lipid usually contains no ester bonds?
* cholesterol
triacylglycerides
glycerophospholipids
None of the above, all dietary lipids are esterified.
E. All of the above
1054.
Which enzyme is needed for the oxidation of odd-chain saturated fatty acids that
is not needed for even-chain fatty acids?
A. methylmalonyl-CoA mutase
B. * propionyl-CoA carboxylase
C. methylmalonyl-CoA racemase
D. all of the above
E. none of the above.
1055.
Which enzyme is needed for the oxidation of odd-chain saturated fatty acids that
is not needed for even-chain fatty acids?
A. methylmalonyl-CoA mutase
B. propionyl-CoA carboxylase
C. methylmalonyl-CoA racemase
D. * all of the above
E. none of the above
1056.
Which enzyme requires adenosylcobalamin as a cofactor?
A. carnitine acyl transferase I
B. * methylmalonyl-CoA mutase
C. enoyl-CoA hydratase
D. propionyl-CoA carboxylase
E. none of the above
1057.
Which lipid form is transported across the inner mitochondrial membrane before
?-oxidation?
A. * acylcarnitine
B. fatty acyl CoA
C. acetoacetyl CoA
D. lysophospholipid CoA
E. none of the above.
1058.
Which lipid form is transported across the inner mitochondrial membrane before
?-oxidation?
A. * acylcarnitine
B. fatty acyl CoA
C. acetoacetyl CoA
D. lysophospholipid CoA
E. all of the above
1059.
Which of the below-mentioned acids belongs to bile acids?
A. linoleic acid
B. arachidonic acid
C. oleic acid
D. * cholic acid
E. myristic acid
1060.
Which of the below-mentioned metabolites is formed by oxidation of fatty acids
with odd amount of carbon atoms:
A. * propionyl-CoA
B. butyryl-CoA
C. malonyl-CoA
D. enoil-CoA
E. acetacetyl-CoA
1061.
Which of the following can be oxidized by ? -oxidation pathway?
A. Saturated fatty acids
B. Monounsaturated fatty acids
C. Polyunsaturated fatty acids
D. * All of these
E. A and B
1062.
Which of the following can be synthesized in the human body if precurors are
available?
A. Oleic acid
B. Palmitoleic acid
C. Arachidonic acid
D. * A and B
E. All of these
1063.
Which of the following does (do) not occur during the fasting state?
A. Increased insulin levels
B. Inhibition of lipolysis
C. An increase in the concentration of albumin-bound fatty acids in the blood
D. * a and b only
E. All of the above
1064.
Which of the following is a polyunsaturated fatty acid?
A. Palmitic acid
B. Palmitoleic acid
C. * Linoleic acid
D. Oleic acid
E. All of these
1065.
Which of the following is a true statement for fatty acid synthesis?
A. It occurs in the mitochondria.
B. The reducing power for synthesis is supplied by NAD and ubiquinone.
C. Both a and b.
D. * None of the above.
E. It occurs in the lysosom.
1066.
Which of the following is a true statement for fatty acid oxidation?
A. It occurs in the cytosol.
B. Oxidation requires a three carbon substrate, which transfers a two-carbon unit to
the chain.
C. Both a and b.
D. * None of the above.
E. It occurs in the lysosom.
1067.
Which of the following is not a stage of fatty acid synthesis?
A. Condensation of precursors
B. Dehydration
C. Reduction
D. All of the above
E. * None of the above
1068.
Which of the following is not used in the synthesis of fatty acids?
A. Cobalamin (vitamin B12)
B. NADPH
C. AMP
D. * FADH2
E. HCO3
1069.
Which of the following is not used in the synthesis of fatty acids?
A. Cobalamin (vitamin B12)
B. NADPH
C. AMP
D. * FADH2
E. HCO3
1070.
Which of the following is omega-3 polyunsaturated fatty acid?
A. Linoleic acid
B. * Linolenic acid
C. Palmitoleic acid
D. Arachidonic acid
E. A and B
1071.
Which of the following is required as a reductant in fatty acid synthesis?
A. NADH
B. * NADPH
C. FADH2
D. FMNH2
E. A and B
1072.
Which of the following is the regulated step of fatty acid synthesis in eukaryotes?
A. * Carboxylation of acetyl CoA.
B. Transportation of mitochondrial acetyl CoA into the cytosol.
C. Assembly of the fatty acid chain.
D. All of the above.
E. None of the above.
1073.
Which of the following is the regulated step of fatty acid synthesis in eukaryotes?
A. * Carboxylation of acetyl CoA.
B. Transportation of mitochondrial acetyl CoA into the cytosol.
C. Assembly of the fatty acid chain.
D. All of the above.
E. None of the above
1074.
Which of the following is true for carboxylation of Acetyl CoA?
A. In animals and yeast, it requires three separate protein subunits.
B. It is a metabolically reversible reaction.
C. In bacteria, it is catalyzed by a bifunctional enzyme.
D. All of the above.
E. * None of the above.
1075.
Which of the following lipid is absorbed actively from intestine?
A. Glycerol
B. Cholesterol
C. Monoacylglycerol
D. * None of these
E. A and B
1076.
Which of the following statements correctly describes the enzyme thiokinase?
A. It yields acetyl CoA as a product
B. It yields ADP as a product
C. It yields CoA as a product
D. * It forms CoA thioesters as a product
E. It requires I-ketoacyl CoA as a substrate
1077.
Which one of the following compounds is a key intermediate in the synthesis of
both triacylglycerols and phospholipids?
A. CDP-choline
B. * Phosphatidate
C. Triacylglyceride
D. Phosphatidylserine
E. CDP-diacylglycerol
1078.
Which one of the following compounds is a key intermediate in the synthesis of
both triacylglycerols and phospholipids?
A. CDP-choline
B.
C.
D.
E.
* Phosphatidate
Triacylglyceride
Phosphatidylserine
CDP-diacylglycerol
1079.
Which one of the following is not a phospholipid?
A. Lecithin
B. Plasmalogen
C. Lysolecithin
D. * Gangliosides
E. B and C
1080.
Why are triacylglycerols able to provide more energy than carbohydrates (gram
for gram)?
A. The triacylglycerols have an extremely high group transfer potential.
B. * The carbohydrates are already in a more oxidized state than the triacylglycerols.
C. The carbohydrates contain fewer carbon-carbon bonds.
D. The triacylglycerols are less soluble in water than the carbohydrates.
E. all of the above
1081.
Why is it undesirable to have high concentrations of free fatty acids and
lysophosphoglycerides in cells?
A. They are unstable, free radicals that can react to form toxic substances.
B. They polymerize easily and can cause the cytosol to become too gel-like.
C. * They are amphipathic and act as detergents that can degrade membranes.
D. They inhibit the uptake of pyruvate by mitochondria.
E. all of the above
1082.
?-Oxidation of fatty acids requires all the following coenzymes except
A. CoA
B. FAD
C. NAD
D. * NADP
E. A and B
1083.
?-Oxidation of odd-carbon fatty acid chain produces
A. Succinyl CoA
B. Propionyl CoA
C. Acetyl CoA
D. * Malonyl CoA
E. None of the above
1084.
_______acts to suppress appetite by inhibiting _____ that is the most powerful
known appetite stimulant.
A. Growth hormone; lipase
B. Serotonin; adrenaline
C. Leptin; neuropeptide Y
D. * Insulin; glucagon
E. None of the above
1085.
85% of blood cholesterol is produced
A. * In the liver.
B. By the breakdown of worn out RBCs in the spleen
C. By the ingestion of too much chocolate in the diet.
D. From the breakdown of fatty acids in the digestive system.
E. None of the above
1086.
A Chylomicrons
A. VLDL
B. LDL
C. * HDL
D. Only B
1087.
A compound normally used to conjugate bile acids is
A. Serine
B. * Glycine
C. Glucoronic acid
D. Fatty acid
E. Cholesterol
1088.
A good source of monounsaturated fats is
A. Fat associated with meat.
B. Egg yolks.
C. Whole milk
D. Fish oil.
E. * Olive oil.
1089.
A human physiology student had learned all about diabetes and its symptoms. She
was presented with a case of an obese, middle-aged patient, recently diagnosed with Type
2 Diabetes. Indicate which of the following symptoms does NOT apply to this patient:
A. * Hyperglycemia
B. Glucose present in the urine
C. Insulin resistance
D. Marked plasma insulin deficiency
E. Excessive urine production
1090.
A hydrocarbon formed in cholesterol synthesis is
A. Mevalonate
B. HMG CoA
C. * Squalene
D. Zymosterol
E. Lanosterol
1091.
A lipoprotein associated with high incidence of coronary atherosclerosis is
A. * LDL
B. VLDL
C. IDL
D. HDL
E. None of the above
1092.
A lipoprotein inversely related to the incidence of coronary artherosclerosis is
A. VLDL
B. IDL
C. LDL
D. * HDL
E. B and C
1093.
A low density lipoproteins would contain
A. A high protein content.
B. A high cholesterol content
C. A low lipid content.
D. A high lipid content.
E. A high triacylglycerol content.
1094.
A major cause of atherosclerosis is:
A. * Plaque.
B. High density lipoproteins
C. Unsaturated fats.
D. Monounsaturated fats.
E. Very low density lipoproteins
1095.
A metabolite which is common to pathways of cholesterol biosynthesis from
acetyl-CoA and cholecalciferol formation from cholesterol is
A. Zymosterol
B. Lumisterol
C. Ergosterol
D. * 7 Dehydrocholesterol
E. Lanosterol
1096.
A total blood cholesterol concentration that is less than _____ mg/dl indicates a
low risk of developing CHD, whereas a concentration that is greater than _____ mg/dl
indicates a high CHD risk.
A. * 3; 9
B. 6; 6
C. 7; 8
D. 7,5; 5
E. None of the above
1097.
Acetoacetate transforms into acetone by means of:
A. Dehydrogenating
B. * Decarboxylation
C. Hydration
D. Oxidation
E. Reduction
1098.
Acetoacetate transforms into acetone by means of:
A. Dehydrogenating
B. * Decarboxylation
C. Hydration
D. Oxidation
E. Reduction
1099.
Activated lecithin cholesterol acyl transferase is essential for the conversion of
A. VLDL remnants into LDL
B. * Nascent HDL into HDL
C. HDL2 into HDL3
D. HDL3 into HDL2
E. VLDL into HDL
1100.
Adiposogenital dystrophy is caused by the lack of secretion of:
A. Oxytocin
B. Vasopressin
C. Gonadotropic hormone
D. * Thyrotropic hormone
E. Melanotropic hormone
1101.
All of the following are factors that increase one's risk of hypertension EXCEPT:
A. Lack of exercise
B. Gender.
C. A high-salt diet
D. * Diabetes.
E. All of the above
1102.
All of the following are high in monounsaturated fatty acids EXCEPT:
A. Safflower oil
B. Canola oil.
C. Cashew nuts.
D. * Olive oil.
E. All of the above
1103.
All of the following are risk factors for cardiovascular disease EXCEPT:
A.
B.
C.
D.
E.
* Low blood pressure
Being overweight
Diabetes mellitus
Smoking
None of the above
1104.
All of the following are true regarding HDL-cholesterol levels EXCEPT:
A. That regular physical activity increases HDL
B. That a high saturated fat diet decreases HDL
C. * That a diet high in omega-3 increases HDL
D. That a high fiber diet increases HDL.
E. All of the above
1105.
All of the following hormones would suppress appetite except
A. Leptin released by adipose cells
B. Ghrelin produced in the stomach.
C. Cholecystokinin produced during digestion
D. * Insulin.
E. Epinephrin
1106.
All of the following tissue are capable of using ketone bodies except
A. Brain
B. Renal cortex
C. * R.B.C.
D. Cardiac muscle
E. Sceletal muscle
1107.
All the following can be oxidized by oxidation except
A. Palmitic acid
B. * Phytanic acid
C. Linolic acid
D. Fatty acids having an odd number of carbon atoms
E. Linolenic
1108.
All the following statements correctly describe ketone bodies except
A. They may result from starvation
B. They are present at high levels in uncontrolled diabetes
C. They include—OH ?-butyrate and acetone
D. * They are utilized by the liver during long term starvation
E. Only A
1109.
An enzyme required for the synthesis of ketone bodies as well as cholesterol is
A. Acetyl CoA carboxylase
B. * HMG CoA synthetase
C. HMG CoA reductase
D. HMG CoA lyase
E. None of the above
1110.
Answer both questions a) and b). a) Is the following triacylglycerol chiral? b) Are
any of its hydrolysis products chiral?
A. A) no b) no
B. A) yes b) no
C. * A) yes b) yes
D. A) no b) yes
E. None of the above
1111.
Antioxidant have the ability to:
A. * Level the processes of free-radical oxidation of lipids
B. Depress ?-oxidation of fatty acids
C. Activate fat decomposition
D. Activate the processes of peroxidation
E. Depress ketogenesis
1112.
Arachidonic acid is classified as essential because it:
A. Is needed as a source of energy
B. Is needed as a source of ?-3 acids
C. * Is needed for synthesis of eicosanoids
D. Can be converted to all of the other fatty acids
E. Readily acts as an antioxidant
1113.
Beta-oxidation results in the formation of:
A. Pyruvate.
B. * Acetyl-CoA.
C. Carbon monoxide.
D. Oxaloacetate.
E. None of the above
1114.
By observation of a sick child were discovered phenomena of xanthomatosis, liver
increase, retinal hyperlipemia, pain in the stomach, hyperchilomicronemia. What enzyme
activity malfunction possibly caused such pathology?
A. Lipoprotein lipase
B. * Lecithin cholesterol-acyltransferase
C. Tissue tryglycerol lipase
D. Tissue dyglycerol lipase
E. Pancreatic lipase
1115.
By oxidation of fatty acids with paired amount of carbohydrate atoms propionilCoA is transformed to:
A. Malonyl-CoA
B. Succinyl-CoA
C. Enoil-CoA
D. Butyryl-CoA
E. Acetacetyl-CoA
1116.
c. CH3(CH2)12CO2H d. HOCH2CH(OH)CH2OH
A. A
B. * B
C. C
D. D
E. All of the above
1117.
Can Acetyl-CoA directly be transported from the mitochondrial matrix to the
cytosol?
A. No, oxaloacetate goes over to the cytosol and then acetyl-CoA is produced
B. No, oxaloacetate and acetyl-CoA forms citrate which travels out to the cytosol
C. Yes, acetyl-CoA is directly transferred into the cytosol
D. Yes, oxaloacetate goes over to the cytosol and then acetyl-CoA is produced
E. None of the above
1118.
Cardiovascular function is most commonly impaired by which disease?
A. Arteriosclerosis
B. Hypertension
C. Coronary heart disease
D. Stroke
E. * All of the above
1119.
Cholesterol is a
A. Animal sterol
B. M.F. C27 H46O
C. 5 methyl groups
1120.
1121.
1122.
1123.
1124.
1125.
1126.
1127.
1128.
D. * All of these
E. Non produse energy
Cholesterol is a precursor for each of the following, except:
A. Bile salts
B. Vitamin D
C. Testradiol
D. * Vitamin C
E. Lipoproteins
Cholesterol is a precursor in the biogenesis of
A. Vitamin A
B. * Vitamin D
C. Vitamin E
D. None of these
E. Vitamin K
Cholesterol is essential for normal membrane functions because it
A. Cannot be made by higher organisms, e.g. mammals
B. Spans the thickness of the bilayer.
C. Keeps membranes fluid.
D. Catalyzes lipid flip-flop in the bilayer.
E. Plugs up the cardiac arteries of older men.
Cholesterol is present in all of the following except
A. Egg
B. Fish
C. Milk
D. * Pulses
E. Liver
Cholesterol is transported from liver to extrahepatic tissues by
A. Chylomicrons
B. VLDL
C. HDL
D. * LDL
E. Carnitin
Cholesterol molecule has _______ carbon atoms.
A. * 27
B. 21
C. 15
D. 12
E. 2
Cholesterol performs in the organism the following functions, but:
A. Is a part of cell membranes
B. Substratum for bile acids synthesis
C. Substratum for D vitamin synthesis
D. * Is a source of energy
E. Substratum for steroid hormones synthesis
Cholesterol, bile salts, vitamin D and sex hormones are
A. Mucolipids
B. Glycolipids
C. Phospholipids
D. * Isoprenoid lipids
E. Milk lipids
Chylomicron remnants are catabolised in
A. Intestine
B.
C.
D.
E.
Adipose tissue
Liver
* Liver and intestine
Lung
1129.
Chylomicron, intermediate density lipoproteins (IDL), low density lipoproteins
(LDL) and very low density lipoproteins (VLDL) all are serum lipoproteins. What is the
correct ordering of these particles from the lowest to the greatest density?
A. LDL, IDL, VLDL, Chylomicron
B. * Chylomicron, VLDL, IDL, LDL
C. VLDL, IDL, LDL, Chylomicron
D. Chylomicron, IDL, VLDL, LDL
E. IDL, Chylomicron, VLDL, LDL
1130.
Contributory, or secondary, risk factors for heart disease include
A. Stress, obesity, diabetes.
B. * Heredity, age, high blood pressure
C. Gender, physical inactivity, age
D. Diabetes, smoking, high cholesterol
E. Only C
1131.
Drugs called statins are now used to decrease plasma cholesterol levels by
inhibiting the rate-limiting step of cholesterol synthesis. This step is catalyzed by
A. Lipoprotein lipase
B. * ?-ketothiolase
C. Acyl carrier protein
D. HMG-CoA reductase
E. Transacylase
1132.
During the absorptive state, the primary source of energy for liver cell functions is
A. Keto acids derived from amino acids.
B. * Ketone bodies derived from fatty acids.
C. Lactic acid derived from muscle glycogen.
D. Glucose derived from intestinal absorption.
E. Pyruvate derived from glycolysis.
1133.
Elevated plasma level of the following projects against atherosclerosis:
A. Chylomicrons
B. VLDL
C. HDL
D. * LDL
E. A and B
1134.
Enzyme lecithin cholesterol acyltransferase (LCAT) performs the following
function:
A. * Removal of cholesterol from perifery tissues and its transportation to the liver
B. Formation of chylomicrons
C. Formation of ?-lipoproteins
D. Resynthesis of lipids
E. Formation of cell membranes structure
1135.
?Exercise can help reduce the risk of heart disease by:
A. Reducing the levels of HDL
B. * Increasing the levels of HDL
C. Increasing the levels of LDL
D. Increasing blood pressure
E. Increasing the levels of VLDL
1136.
Familial hypercholesterolemia is associated with loss of function due to defects in
:
A.
B.
C.
D.
E.
* Hydroxymethylglutaryl (HMG)-CoA reductase.
Chylomicrons.
Hormone-sensitive lipase.
Receptors for LDL.
Mevalonatereductase
1137.
Fatty acid oxidation occurs mostly within mitochondria, but fatty acids can't easily
cross the mitochondrial membrane. How do they pass?
A. Attached to alcohols
B. * As esters of carnitine
C. As amides of glycine
D. Attached to esters of alcohols
E. As bile acids or salts
1138.
Fatty acids are activated to acyl-CoAs and the acyl group is further transferred to
carnitine because:
A. Acyl-CoAs easily cross the mitochondrial membrane, but the fatty acids
themselves will not.
B. Fatty acids cannot be oxidized by FAD unless they are in the acyl-carnitine form.
C. Carnitine is required to oxidize NAD+ to NADH.
D. * Acyl-carnitines readily cross the mitochondrial inner membrane, but acyl-CoAs
do not.
E. None of the above is true.
1139.
Fatty acids from hyaloplasm to mitochondria are transported with the help of:
A. * Albumins
B. Chylomicrons
C. ?-? lipoproteins
D. Pre-D-lipoproteins
E. E- lipoproteins
1140.
Fluidity of membranes is increased by the following constituent except
A. * Polyunsaturated fatty acids
B. Saturated fatty acids
C. Integral proteins
D. Cholesterol
E. Lanosterol
1141.
For extramitochondrial fatty acid synthesis, acetyl CoA may be obtained from
A. * Citrate
B. Isocitrate
C. Oxaloacetate
D. Succinate
E. Lactat
1142.
For long-term storage glucose is converted to ______ , while for short-term
storage, glucose is converted to ______.
A. * Fat, glycogen
B. Glycogen, ketone bodies
C. Glycogen, protein
D. Pyruvic acid, fat
E. Fat, pyruvic acid
1143.
HDL is synthesized and secreted from
A. Pancreas
B. * Liver
C. Kidney
D. Muscle
E. Lung
1144.
HDL is synthesized in
A. Adipose tissue
B. * Liver
C. Intestine
D. Liver and intestine
E. Muscle tissue
1145.
High cholesterol can be reduced by all of the following EXCEPT:
A. Proper nutrition.
B. Drug treatment.
C. * Exercise.
D. Increasing saturated fat
E. None of the above
1146.
Hormone, which increase the activity of lipolysis in fatty tissue:
A. * Epinephrine
B. Parathyroid hormone
C. Insulin
D. Vasopressin
E. Prostaglandins
1147.
How many enzymes are there in the palmitate synthase multiferment complex?
A. * 5
B. 2
C. 3
D. 10
E. 7
1148.
In order to estimate your 10-year risk for cardiovascular disease, you need to
know all of the following EXCEPT:
A. Your systolic blood pressure
B. Your weight.
C. * Your age.
D. Your total cholesterol.
E. Your total glucose
1149.
In terms of CHD risk, which of the following is undesirable?
A. * High HDL
B. Low HDL
C. Both low HDL and high LDL together
D. High LDL
E. Low VLDL
1150.
In the blood of a patient is decreased amount of phospholipids, increased
concentration of cholesterol, observed the symptoms of prostaglandin lack. What can
cause such events?
A. Limited usage of carbohydrate
B. * Limited usage of polysaturated fat acids
C. D hypovitaminosis
D. Excess of lipids in food
E. Excess of carbohydrates in food
1151.
In the organism of a patient as a result of vitamin B12 deficiency has evolved fatty
hepatosis. What is the reasone for this?
A. Lecithin synthesis violation
B. Haemopoiesis violation
C. Excessive usage of butter
D. * Lack of inner Castle's factor
E. Ketone bodies synthesis violation
1152.
In the process of ketogenesis and cholesterol genesis is formed general metabolite.
Name it:
A. Mevalonic acid
B. Malonyl KoA
C. Succinil KoA
D. * D-oxy---?metil-glutaryl CoA
E. E-oxy---?citryl-glutaryl CoA
1153.
In those cases were the original fatty acid consists of an uneven number of carbon
atoms, the last cycle of the ?-oxidation will yield a molecule of
A. Acetyl-CoA
B. Glucose
C. * Propionyl-CoA_Succionyl-CoA
D. Oxaloacetate
E. Lactat
1154.
Ketogenesis is stimulated by all of the following except
A. Glucagon.
B. Epinephrine.
C. Thryoxine.
D. * Cortisol.
E. Only B
1155.
Ketone bodies are formed in
A. Kidney
B. * Liver
C. Heart
D. Intestines
E. Muscles
1156.
Ketone bodies are formed in:
A. * Liver
B. Muscles
C. Stomach
D. Intestines
E. Kidney
1157.
Ketone bodies are mainly formed (where)?
A. In the brain
B. In the heart
C. * In the liver
D. In kidney
E. None of the above
1158.
Ketone bodies are synthesized from fatty acid oxidation products by which of the
following organs?
A. * Liver
B. Skeletal muscles
C. Kidney
D. Brain
E. Heard
1159.
Ketosis in partly ascribed to
A. Over production of Glucose
B. * Under production of Glucose
C. Increased carbohydrate utilization
D. Increased fat utilization
E. None of the above
1160.
LCAT activity is associated with which of the lipo-protein complex?
A.
B.
C.
D.
E.
1161.
A.
B.
C.
D.
E.
1162.
A.
B.
C.
D.
E.
1163.
A.
B.
C.
D.
E.
1164.
A.
B.
C.
D.
E.
1165.
A.
B.
C.
D.
E.
1166.
A.
B.
C.
D.
E.
1167.
A.
B.
C.
D.
E.
1168.
A.
B.
C.
D.
VLDL
Chylomicrones
IDL
* HDL
LDL
leaflet of the membrane lipid bilayer?
* Choline phosphoglycerides
Ethanolamine phosphoglycerides
Inositol phosphoglycerides
Serine phosphoglycerides
Only C
Lipid stores are mainly present in
Liver
Brain
Muscles
* Adipose tissue
Lung
Lipids are stored in the body mainly in the form of
Phospholipids
Glycolipids
* Triglycerides
Fatty acids
Cholesterol
Lipids are:
* Stored primarily as triglycerides.
Synthesized by beta-oxidation.
Broken down by oxidative deamination.
All of the above.
None of the above
Lipolysis is accelerated by:
Insulin
* Glucagon
Water
Testosterone
Sucrose
Lipoproteinlipase of tissue capillary is activated by:
* Bile acids
Heparin
Trypsin
Epinephrine
Ions of Ca
Lipoprotiens may be identified more accurately by means of
* Electrophoresis
Ultra centrifugation
Centrifugation
Immunoelectrophoresis
Only C
Mark all forms of ketone bodies, except:
Acetoacetate
Acetone
C-hydroxybutyrate
* Cellulosa
1169.
acids
A.
B.
C.
D.
Mark important molecules and steps directly involved in the oxidation of fatty
Hexokinase/Glucokinase.
Shuttling of Acetyl-CoA with Carnitin
Lactate
* The process starts with the activation of a fat molecule, in which a thioester
bond is formed between the carboxyl group of the fatty acid and the thiol group of
coenzyme A (CoA-SH)
E. Acyl-CoA-synthetase and acyl-CoA
1170.
Mark the lipid, which usage is to be decreased in the daily food allowance:
A. Cholesterol
B. * Oleic acid
C. Lecithin
D. Monooleateglyceride
E. Phosphatidyl serine
1171.
Micelles of fatty acids in water are organized such that the ___ face the solvent
and the ___ are directed toward the interior.
A. Hydrophilic heads; hydrophobic tails
B. Carboxylic acid groups; hydrocarbon chains
C. Hydrocarbon chains; carboxylic acid groups
D. Hydrophobic tails; hydrophilic heads
E. The first and second answers are both correct.
1172.
Mitochondrial lipogenesis requires
A. Bicarbonate
B. Biotin
C. Acetyl CoA carboxylase
D. * NADPH
E. Carnitin
1173.
Most products of fat digestion are transported in the lymph as
A. Glycerol.
B. Fatty acids.
C. * Chylomicrons
D. Cholesterol.
E. HDL
1174.
Normal concentration of ketone bodies in blood is:
A. 2-3 mg/l.
B. 5-10 mg/l.
C. 50-70 mg/l.
D. * 10-20 mg/l.
E. 30-40 mg/l.
1175.
Normal range of plasma total phospholipids is
A. 0.2–0.6 mmol/L
B. 0.9–2.0 mmol/L
C. * 1.5–3.6 mmol/L
D. 2.8–5.3 mmol/L
E. 9,2-11.6 mmol/L
1176.
Number of carbon atoms in cholesterol is
A. 17
B. 19
C. * 27
D. 30
E. 18
1177.
Old-time physicians often diagnosed illness on the basis of the odor of patients.
Untreated diabetics sometimes have breath with a "fruity" odor due to the presence of a
volatile ketone body. Which one?
A. ?-Hydroxybutyric acid
B. Pyruvic acid
C. Stearic acid
D. Acetoacetic acid
E. * Acetone
1178.
Oxidation of fatty acids occurs
A. In the cytosol
B. * In the matrix of mitochondria
C. On inner mitochondrial membrane
D. On the microsomes
E. on the lysosoms
1179.
Pancreatic lipase converts triacylglycerols into
A. 2, 3-Diacylglycerol
B. 1-Monoacylglycerol
C. * 2-Monoacylglycerol
D. 3-Monoacylglycerol
E. 5-Monoacylglycerol
1180.
Pancreatic lipase requires for its activity:
A. Co-lipase
B. Bile salts
C. Phospholipids
D. * All of these
E. Monoacylglicerols
1181.
Phospholipids are important cell membrane components because
A. They have glycerol
B. They can form bilayers in water
C. They have both polar and non polar potions
D. * They combine covalently with proteins
E. None of these
1182.
Products of ?-oxidation of palmitoyl CoA include:
A. Propionyl CoA, NADH and FADH2.
B. Acetyl CoA, NADPH and FAD.
C. * Acetyl CoA, FADH2 and NADH.
D. Propionyl CoA, NADH and acetyl CoA.
E. Pyruvat and lactat
1183.
Serum cholesterol is decreased in
A. Endemic goitre
B. Thyrotoxicosis
C. Myxoedema
D. Cretinism
E. Pellsgra
1184.
Some triacylglycerols are exogenous, and others are endogenous (synthesized
within the body). Endogenous triacylglycerols are typically synthesized in:
A. Erythrocytes
B. Liver
C. Heart tissue
D. Muscle tissue
E. * Adipose tissue
1185.
Some ways to reduce the risk of cardiovascular disease are:
A. Quit smoking and reduce saturated fat intake.
B. Reduce exercise to prevent stress on the heart.
C. Obtain 50% or more of total calorie intake from fat and decrease carbohydrate
intake.
D. * All of the above.
E. None of the above
1186.
Stress is considered a risk factor for heart disease because it can cause all of the
following EXCEPT:
A. An increase in blood pressure.
B. An increase in HDL levels.
C. * An increase in smoking.
D. An increase in total blood cholesterol
E. Only D
1187.
The ‘Committed step’ in the biosynthesis of cholesterol from acetyl CoA is
A. Formation of acetoacetyl CoA from acetyl CoA
B. Formation of mevalonate from HMG CoA
C. * Formation of HMG CoA from acetyl CoA and acetoacetyl CoA
D. Formation of squalene by squalene synthetase
E. Only A
1188.
The action of bile in lipid digestion is to:
A. * Emulsify fats by a detergent action
B. Chemically degrade triglycerides to fatty acids and glycerol
C. Chemically convert triglycerides to diglycerides
D. Chemically reduce cholesterol esters to cholesterol
E. A and B
1189.
The amount of cholesterol in blood plasma is normal:
A. * 3-7 mmol/l
B. 10-15 mmol/l
C. 20-25 mmol/l
D. 1-3 mmol/l
E. 5-7 mmol/l
1190.
The amount of total lipids in blood plasma is normal:
A. 4-8 g/l
B. 5-10 g/l
C. 2-3 g/l
D. 15-20 g/l
E. 7-12 g/l
1191.
The anabolism/synthesis of lipids mainly take place in the
A. * Cytosol
B. Mitochondrial matrix
C. Nucleus
D. Cell membrane
E. Lysosoms
1192.
The biggest risk factor for sudden cardiac death is:
A. Heredity.
B. Smoking
C. Hipertension.
D. * High blood cholesterol levels
E. Low blood cholesterol levels
1193.
The bile salts are:
A. Enzymes for digesting food in the small intestines
B. * Detergents for breaking up large fat globules to small ones
C. Stimulants to pancreatic secretion of enzymes
D. The major ingredients of gallstones
E. Reabsorbed primarily by the gallbladder
1194.
The catabolism/breakdown of lipids (?-oxidation) mainly take place in the
A. Cytosol
B. * Mitochondrial matrix
C. Nucleus
D. Cell membrane
E. Lysosoms
1195.
The complete h-oxidation of 1 mole of palmitic acid to CO2 and H2O yields
_______ net moles of ATP.
A. 92
B. 94
C. 106
D. 108
E. * 129
1196.
The correct sequence of events that occurs when fatty acids are used to generate
ATP is:
A. Beta-oxidation, electron transport chain, deamination.
B. Electron transport chain, beta-oxidation, glycolysis.
C. * Beta-oxidation, TCA cycle, electron transport chain.
D. Glycolysis, beta-oxidation, TCA cycle.
E. Glycolysis, electron transport chain, deamination
1197.
The cyclization of squalene causes the formation of:
A. * Lanosterol
B. B-oxy---methylglutaryl-CoA
C. Phosphomevalonate
D. Acetoacetyl-CoA
E. Cholesterol
1198.
The fatty degeneration of liver is prevented by lipotropic matters. Which of the
belowmentioned matters belongs to them?
A. * Methionine
B. Cholesterol
C. Bilirubin
D. Glycine
E. Glucose
1199.
The fatty degeneration of liver is prevented by lipotropic matters. Which of the
belowmentioned matters belongs to them?
A. * Methionine
B. Cholesterol
C. Bilirubin
D. Glycine
E. Glucose
1200.
The following contains the least cholesterol:
A. * Milk
B. Meat
C. Butter
D. Cheese
E. Suet
1201.
The function of pentose-phosphate cycle in the synthesis of fatty acids and
cholesterol is the following:
A. Main energy source
B.
C.
D.
E.
Source of acetyl-CoA
Source of malonyl-CoA
* Source of NADPH2
Source of NAPH2
1202.
The highest phospholipids content is found in
A. Chylomicrons
B. VLDL
C. LDL
D. * HDL
E. None of the above
1203.
The hormone, that depresses lipolysis in fatty tissue:
A. * Insulin
B. Epinephrine
C. Glucagon
D. Thyroxine
E. Adrenocorticotropin
1204.
The hormone, that depresses lipolysis in fatty tissue:
A. * Insulin
B. Epinephrine
C. Glucagon
D. Thyroxine
E. Adrenocorticotropin
1205.
The hormone, which favours oxidation of cholesterol side chain and its excretion
with bile:
A. Parathyroid hormone
B. * Epinephrine
C. Insulin
D. Thyroxine
E. Vasopressin
1206.
The key intermediate in the synthesis of cholesterol following the formation of
acetoacetyl CoA are. Any one of the following:
A. Hydroxymethylglutaryl CoA or HMG CoA
B. * Mevalonate (or mevalonic acid)
C. Isoprenoid
D. Squalene
E. Lanosterol
1207.
The key intermediate in the synthesis of cholesterol following the formation of
acetoacetyl CoA are. Any one of the following:
A. Hydroxymethylglutaryl CoA or HMG CoA
B. * Mevalonate (or mevalonic acid)
C. Isoprenoid
D. Squalene
E. Lanosterol
1208.
The major lipid in chylomicrons is
A. * Triglycerides
B. Phospholipids
C. Cholesterol
D. Free fatty acids
E. Lanosterol
1209.
The major product of the fatty acid synthase reaction is:
A. Propionyl CoA.
B. * Palmitate.
C. Palmitoyl CoA.
D. Acetyl CoA.
E. Lactat
1210.
The major source of cholesterol in arterial smooth muscle cells is from
A. IDL
B. * LDL
C. HDL
D. Chylomicrons
E. IDL
1211.
The major storage form of lipids is
A. Esterified cholesterol
B. Glycerophospholipids
C. * Triglycerides
D. Sphingolipids
E. All of the above
1212.
The normal content of cholesterol in blood is:
A. 5-10 mmol/l.
B. 10-15 mmol/l.
C. * 3-8 mmol/l.
D. 2-5 mmol/l.
E. 3,3-5,5 mmol/l
1213.
The official medical measurement of obesity is the
A. Weight of a person compared to their height
B. * Body mass index.
C. Proportion of bone density to weight.
D. Basal metabolic rate.
E. Only C
1214.
The oxidation of glycerin in aerobic conditions to CO2 and H2O taking into
account energy spending causes the formation of :
A. 9 ATP molucules
B. 1 ATP molucules
C. 3 ATP molucules
D. * 22 ATP molucules
E. 15 ATP molucules
1215.
The patient has hyperfunctioning of thyroid gland. What changes of lipid
metabolism may take place?
A. Hypercholesterolemia
B. Hypophospholipidemia
C. * Decrease of amount of free fatty acids in blood
D. Steatorrhea
E. Adiposity
1216.
The patient has hyperfunctioning of thyroid gland. What changes of lipid
metabolism may take place?
A. Hypercholesterolemia
B. Hypophospholipidemia
C. * Decrease of amount of free fatty acids in blood
D. Steatorrhea
E. Adiposity
1217.
The presence of ketone bodies in the urine indicates increased metabolism of:
A. * Amino acids.
B. Lactic acid.
C. Fatty acids.
D. Nucleic acids
E. Vitamins
1218.
The presence of ketone bodies in the urine indicates increased metabolism of:
A. * Amino acids.
B. Lactic acid.
C. Fatty acids.
D. Nucleic acids
E. Vitamins
1219.
The result of hyperketonemia is:
A. Fatty liver degeneration
B. * Acidosis
C. General adiposity
D. Emaciation
E. Atherosclerosis
1220.
The sources of NADPH for synthesis of fatty acids and cholesterol are:
A. Malate dehydrogenase and glycolysis
B. Lactate dehydrogenase and oxidative branch of the pentose phosphate pathway.
C. Malate dehydrogenase and non-oxidative branch of the pentose phosphate
pathway.
D. * Malic enzyme and oxidative branch of the pentose phosphate pathway.
E. None of the above
1221.
The substratum for fatty acids synthesis is:
A. * Acetyl-CoA
B. Acyl-CoA
C. Malonyl-CoA
D. Propionil-CoA
E. Succinyl-CoA
1222.
The synthesis of 1 mole of palmitic acid from 8 moles of acetyl CoA requires
_____ moles of ATP.
A. 2
B. 4
C. 6
D. * 7
E. 8
1223.
This interferes with cholesterol absorption
A. Lipoprotein lipase
B. Creatinase
C. ?-sitosterol
D. * 7-dehydrocholesterol
E. None of the above
1224.
Uncontrolled type I diabetes mellitus
A. * Stimulates increased tissue ketone utilization.
B. If untreated leads to convulsions and death.
C. Stimulates hepatic glycogen synthesis.
D. Results in hypotension.
E. All of the above
1225.
Vasodilators that may mediate local myocardial control of coronary vascular tone
A. Adenosine
B. * Bradykinin
C. Prostaglandins
D. Potassium ions
E. Hydrogen ions
1226.
Very low density lipoproteins are also known as
A. ?-lipoproteins
B. * Pre B--lipoproteins
C. C-lipoproteins
D. None of these
E. Pre-?-lipoproteins
1227.
VLDL remnant may be converted into
A. VLDL
B. * LDL
C. HDL
D. Chylomicrons
E. None of the above
1228.
What are the steps you can take to reduce your high blood cholesterol?
A. Follow the TLC Diet (low saturated fat, low cholesterol).
B. Be more physically active.
C. Lose weight if you are overweight.
D. * Take your cholesterol lowering medication if prescribed.
E. All of the above.
1229.
What changes in lipid metabolism will be caused by insufficiency of somatotropin
excretion?
A. Emaciation
B. * Fatty liver degeneration
C. Atherosclerosis
D. Adiposity
E. Ketonemia
1230.
What is the state called when there is a high level of ketone bodies in the blood?
A. * Ketosis/ketoacidosis
B. Hyperglycemia
C. Hypothermia
D. Hyperaminoacidemia
E. Hypoglycemia
1231.
What is the sub cellular site for the W- oxidation of fatty acids?
A. ucleus
B. * Mitochondria
C. Lysosome
D. Cytosol
E. Nucleus
1232.
What is true regarding the production of ketone bodies:
A. It involves a number of reactions
B. It’s a single reaction with only one enzyme
C. The first step is a condensation reaction in which two molecules acetyl-CoA are
transformed into acetyl-CoA
D. The second step is another condensation reaction and HMG-CoA is formed
E. * Acetoacetate can be either reduced to ?–hydroxybutyrate or through a
decarboxylation reaction it can form acetone
1233.
What is/are true for lipids?
A. They are polar and soluble in water.
B. They are nonpolar and soluble in water.
C. * Steroids, glycolipids, fatty acids, triacylglycerols, phosphoacylglycerols a
sphingolipids are all examples of lipids.
D. Pyruvate, glucose and lactate are all examples of lipids.
E. None of the above
1234.
What is/are true?
A. The synthesis of fatty acids produces energy in the form of ATP
B. The catabolism of fatty acids costs ATP
C. The synthesis of fatty acids costs energy in the form of ATP
D. * The catabolism of fatty acids produces ATP
E. Only C
1235.
Where in the cell is performed the synthesis of palmitic acid?
A. * Cytoplasm
B. Nucleus
C. Lysosomes
D. Mitochondria
E. Microsomes
1236.
Which are the cholesterol esters that enter cells through the receptor-mediated
endocytosis of lipoproteins hydrolyzed?
A. Endoplasmin reticulum
B. * Lysosomes
C. Plasma membrane receptor
D. Mitochondria
E. Nucleus
1237.
Which compounds/coenzymes belong to fatty acid synthesis and not to the
catabolism of the same?
A. FAD
B. NAD+
C. NADH
D. Coenzyme A
E. * Acyl carrier protein (ACP)
1238.
Which food does not have a lot of cholesterol?
A. Steak
B. * Banana
C. Liver.
D. Butter
E. Egg.
1239.
Which is not a ketone body?
A. * Dihydroxyacetone
B. Acetoacetate
C. Acetone
D. D-hydroxybutyrate
1240.
Which lipoprotein contains high levels of cholesterol?
A. HDL
B. Chylomicron
C. VLDL
D. IDL
E. * LDL
1241.
Which of the following are considered major risk factors for CHD?
A. Obesity, gender, heredity
B. * Hypertension, high cholesterol, sedentary lifestyle
C. Diabetes, obesity, stress
D. Smoking, diabetes, stress
E. Only C
1242.
Which of the following does NOT characterize Type 1 diabetes mellitus?
A. Increased glucose utilization due to excessive glucose availability
B. Excessive urination due to the osmotic effect of glucose in the urine
C. Acidosis due to excessive levels of ketones (ketone bodies) in the blood.
D. * Dehydration.
E. Hyperglycemia
1243.
Which of the following effect of insulin is correct?
A. Activates the oxidation of fatty acids.
B. Activates the lipolysis.
C. Inhibits the synthesis of lipids.
D. * Enhances the synthesis of lipids.
E. None of the above
1244.
Which of the following has the highest cholesterol content?
A. Meat
B. Fish
C. * Butter
D. Milk
E. Cheese
1245.
Which of the following has the highest cholesterol content?
A. * Egg yolk
B. Egg white
C. Meat
D. Fish
E. Milk
1246.
Which of the following is not a lipoprotein?
A. Chylomicron
B. * Creatinine
C. LDL
D. HDL
E. VLDL
1247.
Which of the following is NOT a long-term consequence of untreated diabetes?
A. Osteoporosis
B. Heart disease
C. Blindness
D. Kidney disorders leading to kidney failure
E. * Peripheral neuropathy
1248.
Which of the following is not specifically required in the synthesis of fatty acids?
A. Biotin
B. Acetyl -CoA
C. Malonyl-CoA
D. NADH
E. * HCO3 - (CO2)
1249.
Which of the following is not true of the reaction in which malonyl-CoA is
produced during fatty acid synthesis?
A. It requires CO2(or bicarbonate)
B. The cofactor biotin
C. It requires the acyl carrier protein(ACP)
D. * It is stimulated by citrate
E. None of the above
1250.
Which of the following lipoproteins would contribute to a measurement of plasma
cholesterol in a normal person following a 12 hr fast?
A. * High density lipoprotiens
B. Low density lipoproteins
C. Chylomicron
D. Chylomicron remnants
E. All of the above
1251.
Which of the following molecules will be formed from the carbon skeleton of a
ketogenic amino acid?
A. * Acetyl-CoA
B. Oxaloacetate
C. Pyruvate
D. Acetoacetyl-CoA
E. All of the above
1252.
Which of the following statement is correct about membrane cholesterol?
A. The hydroxyl group is located near the centre of the lipid layer
B. Most of the cholesterol is in the form of a cholesterol ester
C. * The steroid nucleus form forms a rigid, planar structure
D. The hydrocarbon chain of cholesterol projects into the extracellular fluid
E. None of the above
1253.
Which of the following statements about genetic influences on obesity is FALSE?
A. * A family history of obesity increases your chances of becoming obese by 25-30
percent.
B. Fifty percent of children with two obese parents are also obese.
C. Genes play a significant role in how your body balances calories and energy.
D. Genes influence body fat and fat distribution.
E. Only C
1254.
Which of the following statements about lipoproteins is TRUE?
A. VLDL transports cholesterol from liver to adipose tissue.
B. LDL transports cholesterol from peripheral tissues to the liver.
C. HDL transports cholesterol from the liver to the peripheral tissues.
D. * Chylomicrons transport triacylglycerols from the small intestine to the liver and
adipose tissue.
E. All the above are true.
1255.
Which of the following statements about membrane lipids is true?
A. Lecithin (phosphatidylcholine), which is used as an emulsifier in margarine and
chocolate, is a sphingolipid.
B. * Glycerophospholipids contain fatty acids linked to glycerol through amide
bonds.
C. Some sphingolipids include oligosaccharides in their structure.
D. Glycerophospholipids are found only in the membranes of plant cells.
E. All of the above
1256.
Which of the following statements regarding the biosynthesis of cholesterol is
FALSE?
A. Cholesterol has the same carbon skeleton as its biosynthetic precursor, lanosterol.
B. * Cholesterol is derived from the dimerization of farnesyl pyrophosphate in a
head-to-head manner.
C. Cyclization of squalene to cholesterol is initiated by acid-catalyzed ring opening
of an epoxide.
D. Cholesterol has three fewer carbon atoms than lanosterol.
E. Only C
1257.
Which of these foods does NOT contain cholesterol?
A. Liver
B. Butter
C. Cheese
D. Eggs
E. * Molasses
1258.
Which one of the following pairs of metabolic pathways occur in mitochondria?
A.
B.
C.
D.
E.
Fatty acid synthesis, ketogenesis
* Citric acid cycle, C-oxidation of saturated fatty acids
Ketogenesis, cholesterol synthesis
Pentose phosphate pathway, glycolysis
Gluconeogenesis, pyrimidine synthesis
1259.
Which one of the following statements about lipids is FALSE?
A. A fatty acid group is present in acylglycerols and sphingolipids.
B. Vitamin A functions in vision.
C. Most phospholipids can by degraded by phospholipases A1, A2, C and D.
D. The synthesis of cholesterol requires acetyl CoA, ATP and NADPH.
E. * The more double bonds present in a fatty acid the higher the melting point.
1260.
Which risk factors place an individual at risk for cardiovascular disease?
A. Gender
B. Socioeconomic status
C. Ethnicity
D. Family history
E. * Age
1261.
Which substrate is used for the activation of acetoacetate in peripheral tissues?
A. * Succinyl-CoA.
B. Acetyl-CoA.
C. Acetoacetyl-CoA.
D. CoA-SH.
E. Aceton
1262.
Which vitamin is derived from cholesterol?
A. A
B. B12
C. * D
D. K
E. E
1263.
With the urine daily healthy human organism excretes the ketone bodies in
amount of:
A. * 40 mg
B. 80 mg
C. 100 mg
D. 10 mg
E. 50 mg
1264.
With the urine daily healthy human organism excretes the ketone bodies in
amount of:
A. * 40 mg
B. 80 mg
C. 100 mg
D. 10 mg
E. 50 mg
1265.
А. Lactic acid
A. Glucose
B. Stearic acid
C. Acetoacetic acid
D. * Acetic acid
1266.
7 years old child was carried into the hospital in the state of allergic shock, which
evolved after wasp's sting. The increased concentration of histamine was detected in the
blood. This amine is formed as a result of reaction of:
A. Dehydration
B.
C.
D.
E.
Deamination
Reduction
* Decarboxylation
Hydrooxidation
1267.
Chymotrypsin in the small intestine hydrolyzes peptide linkages containing
A. Alanine
B. * Pheynl alanine
C. Valine
D. Methionine
E. B and C
1268.
Coenzyme of amino acids decarboxylases is:
A. Thymidine diphosphate
B. Flavin adenine dinucleotide
C. Flavin mononucleotide
D. HS-CoA
E. * PLP
1269.
Free ammonia is released during
A. Oxidative deamination of glutamate
B. Catabolism of purines
C. Catabolism of pyrimidines
D. * All of these
E. Both A and B
1270.
Hyperchlorhydria is:
A. A.Increase of gastric juices general acidity
B. B.Increase of bonded hydrochloric acid in gastric juice
C. * Increase of free hydrochloric acid in gastric juice
D. Increase of lactic acid in gastric juice
E. Increase of pyruvic acid in gastric juice
1271.
In small intestine trypsin hydrolyzes peptide linkages containing
A. * Arginine
B. Histidine
C. Serine
D. Aspartate
E. A and D
1272.
Injuries and burns cause the development of negative nitric balance that is the
result of increase of:
A. Glycolysis
B. Lipolysis
C. * Proteolysis
D. Phosphorolysis
E. Fibrinolysis
1273.
Intrinsic factor is chemically a:
A. Protein
B. * Glycoprotein
C. Mucopolysaccaride
D. Peptide
E. Amino acid
1274.
Most amino acids are substrates for transamination except
A. Alanine
B. * Threonine
C. Serine
D. Valine
E. A and B
1275.
Name the compound in the urine, which is a test of protein putrefaction processes
in the intestine:
A. Urates
B. Urea
C. Creatinine
D. * Indican
E. Lactic acid
1276.
Oxidative conversion of many amino acids to their corresponding –ketoacids
occurs in mammalian:
A. * Liver and kidney
B. Adipose tissue
C. Pancreas
D. Intestine
E. Stomach
1277.
The amino acids abstracted from the liver are not utilized for repair or special
synthesis but are broken down to
A. Keto acids
B. Sulphur dioxide
C. Water
D. * Ammonia
E. A and D
1278.
The amount of general acidity in gastric juice of a patient P. is normal. Which of
the listed numbers is true in this case?
A. A.30-40 mM/l
B. * B.40-60 mM/l
C. 20-30 mM/l
D. 30-50 mM/l
E. 20-40 mM/l
1279.
The example of chromoprotein:
A. Salmine
B. * Catalase
C. Zein
D. Gliadin
E. All of these
1280.
The metabolism of all proteins ingested over and above the essential requirements
is called
A. * Exogenous metabolism
B. Endogenous metabolism
C. Both (A) and (B)
D. Metabolism
E. None of these
1281.
The transaminase activity needs the coenzyme:
A. ATP
B. * B6 – PO4
C. FAD+
D. NAD+
E. TPP
1282.
The unwanted amino acids abstracted from the tissues are either used up by the
tissue or in the liver converted into
A. Ammonia
B. * Urea
C. Ammonium salts
D. Uric acid
E. B and C
1283.
Transamination is a
A. Irreversible process
B. * Reversible process
C. Both (A) and (B)
D. Linear pathway
E. None of these
1284.
A limiting amino acid is an essential amino acid
A. * That is most deficient in proteins
B. That is most excess in proteins
C. That which increases the growth
D. That which increases the weight gain
E. None of these
1285.
A positive nitrogen balance occurs
A. * In growing infant
B. Following surgery
C. In advanced cancer
D. In kwashiorkor
E. A and D
1286.
Absorption of Vitamin B12 requires the presence of:
A. Pepsin
B. Hydrochloric acid
C. Intrinsic factor
D. * Boh (B) and (C)
E. Rennin
1287.
Achylia gastrica is said to be when absence of
A. Pepsin only
B. * Both pepsin and HCl
C. HCl only
D. Bile
E. None of these
1288.
Achylia gastrica is said to be when absence of
A. Pepsin only
B. * Both pepsin and HCl
C. HCl only
D. Bile
E. All of these
1289.
Achylia is lack of:
A. Gastric juices acidity
B. Pepsin in gastric juices
C. * Pepsin and hydrochloric acid in gastric juices
D. Free hydrochloric acid in gastric juices
E. Lactic acid in gastric juices
1290.
Active trypsin formation by the action of enteropeptidase can be viewed as the
master activation step because
A. It occurs first
B. * It can activate its own zymogen
C. Trypsin activates other pancreatic zymogens
D. a and b
E. a, b and c
1291.
A.
B.
C.
D.
E.
1292.
A.
B.
C.
D.
E.
1293.
A.
B.
C.
D.
E.
1294.
A.
B.
C.
D.
E.
1295.
A.
B.
C.
D.
E.
1296.
A.
B.
C.
D.
E.
1297.
A.
B.
C.
D.
E.
1298.
A.
B.
C.
D.
E.
1299.
A.
B.
C.
After digestion amino acids
* Are absorbed into portal circulation
Are absorbed into lymph
Are excreted to the extent of 50%
Converted into glucose in the intestine
Both A and B
After digestion amino acids
* Are absorbed into portal circulation
Are absorbed into lymph
Are excreted to the extent of 50%
Converted into glucose in the intestine
All of the above
Alanine aminotransferase (ALT) transfers an amino group from alanine to:
Pyruvate
* alpha-ketoglutarate
Oxaloacetate
Methionine
Carbamoyl phosphate
Alanine can be synthesized from
Glutamate and ?-ketoglutarate
* Pyruvate and glutamate
Pyruvate and ? -ketoglutarate
Asparate and ? –ketoglutarate
All of these
All of the following are required for synthesis of alanine except
Pyruvate
* ? -ketoglutarate
Glutamate
Pyridoxal phosphate
Both a and C
All of the following statements about aspartate are true except
It is non-essential amino acid
It is a dicarboxylic amino acid
* It can be synthesized from pyruvate and glutamate
It can be converted into asparagine
Both A and B
All the following are branched chain amino acids except
Isoleucine
* Alanine
Leucine
Valine
Both A and B
All the following are true about phenylketonuria except
Deficiency of phenylalanine hydroxylase
Mental retardation
* Increased urinary excretion of p-hydroxyphenyl pyruvic acid
Decrease serotonin formation
C and D
All the following statements about pepsin are correct except
It is smaller than pepsinogen
It is formed by the action of HCl on its precursor
Its optimum pH is 1.0–2.0
1300.
1301.
1302.
1303.
1304.
1305.
1306.
1307.
1308.
D. * It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
E. C and D
All the following statements about pepsin are correct except
A. It is smaller than pepsinogen
B. It is formed by the action of HCl on its precursor
C. Its optimum pH is 1.0–2.0
D. * It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
E. Both A and D
Allosteric inhibitor of glutamate dehydrogenase is
A. * ATP
B. ADP
C. AMP
D. GMP
E. None of these
Allsoteric activator of glutamate dehydrogenase is
A. ATP
B. GTP
C. * ADP and GDP
D. AMP and GMP
E. AMP
Amino acids from N-end in the proteins are splittted off by
A. Dipeptidase
B. Carbooxypeptidase
C. * Aminopeptidase
D. Elastase
E. Endopeptidase
Amino acids provide the nitrogen for the synthesis of
A. * The bases of the phospholipids
B. Uric acid
C. Glycolipids
D. Chondroitin sulphates
E. All of these
Amino acids provide the nitrogen for the synthesis of
A. * The bases of the phospholipids
B. Uric acid
C. Glycolipids
D. Chondroitin sulphates
E. None of these
Ammonia intoxication symptoms occur when brain ammonia levels are
A. Slightly diminished
B. Highly diminished
C. * Increased
D. Normal
E. All of these
Ammonia is transported from muscles to liver mainly in the form of
A. Free ammonia
B. Glutamine
C. Asparagine
D. * Alanine
E. Both B and D
An organ which is extremely sensitive to ammonia toxicity is
A. Liver
B.
C.
D.
E.
1309.
A.
B.
C.
D.
E.
1310.
A.
B.
C.
D.
E.
1311.
A.
B.
C.
D.
E.
1312.
A.
B.
C.
D.
E.
1313.
A.
B.
C.
D.
E.
1314.
A.
B.
C.
D.
E.
1315.
A.
B.
C.
D.
1316.
A.
B.
C.
D.
E.
1317.
* Brain
Kidney
Heart
Both A and B
As a result of amino acids decarboxylation in the organism are formed:
Ammonia, urea, creatine
* Amines, diamines
Polypeptides, uric acid
Dipeptides, xanthine
Amines, indican
As a result of amino acids decarboxylation in the organism are formed:
Ammonia, urea, creatine
* Amines, diamines
Polypeptides, uric acid
Dipeptides, xanthine
Allantion, indican
Aspartate amino transferase uses the following for transamination:
Glutamic acid and pyruvic acid
* Glutamic acid and oxaloacetic acid
Aspartic acid and pyruvic acid
aspartic acid and keto adipic acid
None of these
Bioactive amines are formed in reaction of:
Transamination.
* Decarboxylisation.
Oxidation.
Deamination.
All of these
Biological value of a protein is
The percentage of ingested protein/nitrogen absorbed into circulation
* The percentage of ingested protein/nitrogen in the body
The percentage of ingested protein utilized for protein synthesis in the body
The gain in body weight (gm) per gm of protein ingested
Both A and B
By overheating the nutritional value of cereal proteins is
Increased
* Decreased
Unchanged
None of these
D and C
Carboxy peptidase B in the small intestine hydrolyzes peptides containing
Leucine
Isoleucine
* Arginine
Cysteine
Carboxy peptidase B in the small intestine hydrolyzes peptides containing
Leucine
Isoleucine
* Arginine
Cysteine
C and D
Carboxypeptidase, an enzyme of pancreatic juice, contains
A.
B.
C.
D.
E.
Mn
* Zinc
Magnesium
Manganese
Iron
1318.
Carboxypeptidase, an enzyme of pancreatic juice, contains
A. Mn
B. * Zinc
C. Magnesium
D. Manganese
E. All of the above
1319.
Choose from the below mentioned substances the product, which concentration is
increased during putrefying of proteins:
A. * Indole, phenol
B. Creatinine, creatine
C. Cyanocobalamin, naphthoquinone
D. Thiamine, biotin
E. Tryptophane, arginine
1320.
Chymotrypsin in the small intestine hydrolyzes peptide linkages containing
A. Alanine
B. * Pheynl alanine
C. Valine
D. Methionine
E. Both A and B
1321.
Chymotrypsinogen is transformed to chymotrypsin in the effect of:
A. Renin, gastrixin
B. Elastase, enterokinase
C. Hydrochloric acid, pepsin
D. * Trypsin, chymotrypsin
E. Pepsin, enterokinase
1322.
Clinical features of Kwashiorkor include all of the following except
A. * Mental retardation
B. Muscle wasting
C. Oedema
D. Anaemia
E. Both A and D
1323.
Conversion of tyrosine to dihydroxyphenylalanine is catalysed by tyrosine
hydroxylase which requires
A. NAD
B. FAD
C. ATP
D. * Tetrahydrobiopterin
E. PLP
1324.
Daily excretion of nitrogen by an adult man is about
A. 15–20 mg
B. 1.5–2 gm
C. * 5–10 gm
D. 15–20 gm
E. 2-3 mg
1325.
Deamination is ______ of amino group.
A. * Removal
B. Addition
C. Supplementation
D. None of these
E. Both B and C
1326.
Deamination is ______ of amino group.
A. * Removal
B. Addition
C. Supplementation
D. Transfer
E. None of these
1327.
DOPA is an intermediate in the synthesis of
A. Thyroid hormones
B. Catecholamines
C. Melanin
D. * Catecholamines and melanin
E. All of these
1328.
During denaturation of proteins, all of the following are disrupted except
A. * Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
E. Both A and C
1329.
Enzyme catalyzed hydrolysis of proteins produces amino acids of the form:
A. D
B. * L
C. DL
D. G
E. All of these
1330.
Enzyme catalyzed hydrolysis of proteins produces amino acids of the form:
A. D
B. * L
C. DL
D. All of these
E. None of these
1331.
From dietary protein as well as from the urea present in fluids secreted into the
gastrointestinal tract intestinal bacteria produce
A. Carbondioxide
B. * Ammonia
C. Ammonium sulphate
D. Creatine
E. A and D
1332.
From dietary protein as well as from the urea present in fluids secreted into the
gastrointestinal tract intestinal bacteria produce
A. Carbondioxide
B. * Ammonia
C. Ammonium sulphate
D. Creatine
1333.
From two amino acids peptide bond formation involves removal of one molecule
of
A. * Water
B. Ammonia
C. Carbon dioxide
D. Carboxylic acid
E. Both A and B
1334.
GABA(gama amino butyric acid) is
A. Post-synaptic excitatory transmitter
B. * Post-synaptic inhibitor transmitter
C. activator of glia-cell function
D. inhibitor of glia-cell function
E. Both B and C
1335.
Gastrin stimulates
A. Gastric motility
B. Gastric secretion
C. * Both (A) and (B)
D. None of these
E. Increase of gastric juice pH
1336.
Histamine is formed from histidine by
A. Deamination
B. Dehydrogenation
C. * Decarboxylation
D. Carboxylation
E. Oxidation
1337.
Histidine is converted to histamine through the process of
A. Transamination
B. * Decarboxylation
C. Oxidative deamination
D. Urea cycle
E. TCA
1338.
If one amino acid is fed excess, the absorption of another is
A. Slightly accelerated
B. Moderately accelerated
C. Highly accelerated
D. * Retarded
E. Both C and D
1339.
If one amino acid is fed excess, the absorption of another is
A. Slightly accelerated
B. Moderately accelerated
C. Highly accelerated
D. * Retarded
E. None of the above
1340.
If the amino group and a carboxylic group of the amino acid are attached to same
carbon atom, the amino acid is called as
A. * Alpha
B. Beta
C. Gamma
D. Epsilon
E. Delta
1341.
In a person increase in weight in gms per gm of protein consumption represents
A. * Protein efficiency ratio
B. Digestibility value of proteins
C. Biological value of proteins
D. Net protein utilisation
E. All of these
1342.
In carcinoid syndrome the argentaffin tissue of the abdominal cavity overproduce
A. * Serotonin
B.
C.
D.
E.
Histamine
Tryptamine
Tyrosine
All of these
1343.
In case of severe denaturation of protein, there is
A. Reversible denaturation
B. Moderate reversible denaturation
C. * Irreversible denaturation
D. B and C
E. None of these
1344.
In glycoproteins the carbohydrate is in the form of disaccharide units, the number
of units are
A. 50–100
B. 200–300
C. 400–500
D. * 600–700
E. None of these
1345.
In human and other ureotelic organisms, the end product of amino acid nitrogen
metabolism:
A. Bile acids
B. Ketone bodies
C. * Urea
D. Barium sulphate
E. Ammonia
1346.
In humans, NH3 is detoxified in liver as
A. Creatinine
B. Uric acid
C. * Urea
D. Uronic acid
E. All of these
1347.
In quaternary structure, subunits are linked by
A. Peptide bonds
B. Disulphide bonds
C. Covalent bonds
D. * Non-covalent bonds
E. Both A and B
1348.
In small intestine trypsin hydrolyzes peptide linkages containing
A. * Arginine
B. Histidine
C. Serine
D. Aspartate
E. All of these
1349.
In the stomach act such proteolytic enzymes:
A. Trypsin, chymotrypsin
B. Pepsin, enterokinase
C. Trypsin, renin
D. * Pepsin, gastrixin, rennin
E. Chymotrypsin, enterokinase
1350.
In which part of polypeptide chain aminopeptidases break down peptides?
A. From the end of free carboxyl group
B. * From the end of free amino group
C. From the end of free imino group
D. Bonds between aminodicarbonic acids
E. Bonds between cyclic amino acids
1351.
Inactive zymogens are precursors of all the following gastrointestinal enzymes
except
A. Carboxypeptidase
B. Pepsin
C. * Amino peptidase
D. Chymotrypsin
E. Both B and D
1352.
Inactive zymogens are precursors of all the following gastrointestinal enzymes
except
A. Carboxypeptidase
B. Pepsin
C. * Amino peptidase
D. Chymotrypsin
E. A and C
1353.
Insufficiency of which vitamin does cause the inhibition of activity of
aminotransferase’s and decarboxylase?
A. B3
B. B2
C. B6
D. B12
E. B15
1354.
Kwashiorkor occurs when the diet is severely deficient in
A. Iron
B. Calories
C. * Proteins
D. Essential fatty acids
E. Both B and C
1355.
Kwashiorkor usually occurs in
A. * The post-weaning period
B. Pregnancy
C. Lactation
D. Old age
E. Both B and C
1356.
Maple syrup urine diseases is an inborn error of metabolism of
A. Sulphur-containing amino acids
B. Aromatic amino acids
C. * Branched chain amino acids
D. Dicarboxylic amino acids
E. All of these
1357.
Marasmus differs from Kwashiorkor in the which of these following respect
A. Mental retardation occurs in kwashiorkor but not in marasmus
B. Growth is retarded in kwashiorkor but not in marasmus
C. Muscle wasting occurs in marasmus but not kwashiorkor
D. * Subcutaneous fat disappears in marasmus but not in kwashiorkor
E. All of these
1358.
Marasmus occurs from deficient intake of
A. Essential amino acids
B. Essential fatty acids
C. * Calories
D. Zinc
E. All of these
1359.
More than half of the protein of the liver and intestinal mucosa are broken down
and resynthesised in
A. * 10 days
B. 12 days
C. 15 days
D. 18 days
E. All of the above
1360.
Most amino acids are substrates for transamination except
A. Alanine
B. * Threonine
C. Serine
D. Valine
E. Glutamate
1361.
Most of the ammonia released from L-?-amino acids reflects the coupled action of
transaminase and
A. * L-glutamate dehydrogenase
B. L-amino acid oxidase
C. Histidase
D. Serine dehydratase
E. All of these
1362.
Naturally occurring amino acids have
A. * L-Configuration
B. D-Configuration
C. DL-Configuration
D. F-Configuration
E. None of these
1363.
Negative nitrogenous balance is observed in all listed cases, except:
A. Kidney disease
B. * Domination of animal proteins in food
C. Domination of vegetable proteins in food
D. In old age
E. Pancreatitis
1364.
Net protein utilization depends upon
A. Protein efficiency ratio
B. Digestibility coefficient
C. Digestibility coefficient and protein efficiency ratio
D. * Digestibility coefficient and biological value
E. Both A and D
1365.
NH3 is detoxified in brain chiefly as
A. Urea
B. Uric acid
C. Creatinine
D. * Glutamine
E. Alanine
1366.
Number of amino acids present in the dietary proteins:
A. 22
B. 23
C. * 20
D. 19
E. 12
1367.
Oxaloacetate is converted to aspartic acid by
A.
B.
C.
D.
E.
Reductase
Oxidase
* Transminase
Catalase
Decarboxylase
1368.
Oxidative conversion of many amino acids to their corresponding –ketoacids
occurs in mammalian:
A. * Liver and kidney
B. Adipose tissue
C. Pancreas
D. Intestine
E. All of these
1369.
Pancreatic juice contains all of the following except
A. Trypsinogen
B. Lipase
C. * Cholecystokinin
D. Chymnotrypsinogen
E. Both C and D
1370.
Pancreatic juice contains the precursors of all of the following except
A. Trypsin
B. Chymotrypsin
C. Carboxypeptidase
D. * Aminopeptidase
E. Both c and D
1371.
Pancreatic juice contains the precursors of all of the following except
A. Trypsin
B. Chymotrypsin
C. Carboxypeptidase
D. * Aminopeptidase
E. C and D
1372.
Patient has hyperplasia of G-cells of antral part of stomach. What changes in
gastric juice are most possible for this pathology?
A. * Hyperchlorhydria
B. Hypochlorhydria
C. Achlorhydria
D. Achylia
E. Presence of lactic acid
1373.
Patient has positive nitrogenous balance. The reason of this can be:
A. Starvation
B. Tuberculosis
C. * Pregnancy
D. Cancer
E. AIDS
1374.
Patient with enterocolitis has affected protein metabolism. What mechanism of
amino acids absorption is affected?
A. Pinocytosis
B. Primary active transport
C. Simple diffusion
D. * Secondary sodium-dependent transport
E. Phagocytosis
1375.
Pentagastrin is a
A. Naturally occurring form of gastrin
B.
C.
D.
E.
1376.
A.
B.
C.
D.
E.
1377.
A.
B.
C.
D.
E.
1378.
A.
B.
C.
D.
E.
1379.
A.
B.
C.
D.
E.
1380.
A.
B.
C.
D.
E.
1381.
A.
B.
C.
D.
E.
1382.
A.
B.
C.
D.
E.
1383.
A.
B.
C.
D.
E.
Inactive metabolite of gastrin
Active metabolite of gastrin
* Synthetic form of gastrin
Both A and B
Physiologically active configuration of amino acids:
*L
D
A
For some amino acids it is either of two
Neither L nor D
Plasma proteins are isolated by
Salting out
Electrophoresis
Flourimetry
* Both (A) and (B)
All of the above
Progressive transmethylation of ethanolamine gives
Creatinine
Choline
* Methionine
N-methyl nicotinamide
Adenine
Protein anabolism is stimulated by
ACTH
* Testosterone
Glucagon
Epinephrine
All of these
Protein anabolism is stimulated by
ACTH
* Testosterone
Glucagon
Epinephrine
Both B and C
Protein catabolism is stimulated by all below mentioned exept
ACTH
* Testosterone
Glucagon
Epinephrine
A and D
Proteins produce polypeptides from proteins by
Oxidizing
Reducing
* Hydrolyzing
All of these
None of these
Proteins produce polypeptides from proteins by
Oxidizing
Reducing
* Hydrolyzing
None of these
B and C
1384.
Proteins react with biuret reagent which is suggestive of 2 or more
A. Hydrogen bonds
B. * Peptide bonds
C. Disulphide bonds
D. Hydrophobic bonds
E. Both B and C
1385.
Pyridoxal phosphate is involved in which type of reaction?
A. oxidation of pyruvate
B. * production of new amino acids by transamination
C. phosphate-transfer to produce ATP from ADP
D. the regeneration of methionine from homocysteine
E. A and B
1386.
Pyridoxal phosphate is the active coenzyme form of vitamin:
A. B1.
B. B2.
C. B3.
D. * B6.
E. B12
1387.
Pyruvic acid can be obtained by transamination of alanine with
A. * ?- keto glutaric acid
B. Acetoacetic acid
C. OH butyric acid
D. Phosphoenol Pyruvic acid
E. Both A and C
1388.
Rennin acts on casein of milk in infants in presence of
A. Mg++
B. Zn++
C. Co++
D. * Ca++
E. Both C and D
1389.
Rennin acts on casein of milk in infants in presence of
A. Mg++
B. Zn++
C. Co++
D. * Ca++
E. B and D
1390.
Secretion of gastrin is evoked by
A. Entry of food into stomach
B. Vagal stimulation
C. Lower aliphatic alcohols
D. * All of these
E. None of these
1391.
Sulphur containing amino acids after catabolism produces a substance which is
excreted:
A. SO2
B. HNO3
C. * H2SO4
D. H3PO4
E. All of these
1392.
Sulphur-containing amino acid is
A. Glutathione
B. Chondroitin sulphate
C. * Homocysteine
D. Tryptophan
E. Alanine
1393.
The acceptor of amino group in the processes of transamination is:
A. Pyruvate
B. Oxaloacetate
C. * CC-ketoglutarate
D. Fumarate
E. Dioxyacetonephosphate
1394.
The acceptor of amino group in the processes of transamination is:
A. Pyruvate
B. Oxaloacetate
C. * C.? ?-ketoglutarate
D. Fumarate
E. Dioxyacetonephosphate
1395.
The activator of trypsinogen is:
A. Hydrochloric acid
B. Chymotrypsin
C. * Enterokinase
D. Aminopeptidase
E. Carboxypeptidase
1396.
The activity of mammalian L-amino acid oxidase, an FMN – flavo protein, is
quite
A. * Slow
B. Rapid
C. Both (A) and (B)
D. Sensitive
E. None of these
1397.
The amino acid that undergoes oxidative deamination at significant rate is
A. Alanine
B. Aspartate
C. * Glutamate
D. Glutamine
E. All of these
1398.
The amino acid which synthesizes many hormornes:
A. Valine
B. * Phenylalanine
C. Alanine
D. Histidine
E. Both B and C
1399.
The amino acids abstracted from the liver are not utilized for repair or special
synthesis but are broken down to
A. Keto acids
B. Sulphur dioxide
C. Water
D. * Ammonia
E. Uric acid
1400.
The amount of total acidity in gastric juice of a patient P. is normal. Which of the
listed numbers is true in this case?
A. A.30-40 mM/l
B. * B.40-60 mM/l
C. 20-30 mM/l
D. 30-50 mM/l
E. 20-40 mM/l
1401.
The basic amino acids are
A. * Lysine
B. Bile acids
C. Glycine
D. Alanine
E. All of these
1402.
The building up and breaking down of protoplasm are concerned with the
metabolism of
A. Carbohydrate
B. Lipid
C. * Protein
D. Minerals
E. C and D
1403.
The chemical score of different proteins is calculated in terms of
A. * Egg proteins
B. Milk proteins
C. Fish proteins
D. Wheat proteins
E. All of these
1404.
The end product of amino acid nitrogen metabolism in uricotelic organisms
(reptiles and birds) is
A. Bilirubin
B. Urea
C. * Uric acid
D. Biliverdin
E. Ammonia
1405.
The essential amino acids
A. Must be supplied in the diet because the organism has lost the capacity to aminate
the corresponding ketoacids
B. * Must be supplied in the diet because the human has an impaired ability to
synthesize the carbon chain of the corresponding ketoacids
C. Are identical in all species studied
D. Are defined as those amino acids which cannot be synthesized by the organism at
a rate adequate to meet metabolic requirements
E. Both B and D
1406.
The example of phosphoprotein:
A. Mucin
B. * Ovovitellin
C. Ovomucoid
D. Tendomucoid
E. All of the above
1407.
The gain in body weight (gm) per gm of protein ingested is known as
A. Net protein utilisation
B. * Protein efficiency ratio
C. Digestibility coefficient
D. Biological value of protein
E. Both A and B
1408.
The half-life of antibody protein is about
A. 4 weeks
B. 3 weeks
1409.
1410.
1411.
1412.
1413.
1414.
1415.
1416.
1417.
C. * 2 weeks
D. 1 week
E. None of the above
The main enzymatic reaction requiring pyridoxal phosphate as a coenzyme is :
A. Decarboxilation
B. * Transamination
C. Deamination
D. Reamination
E. Oxidation
The main sites for oxidative deamination are
A. * Liver and kidney
B. Skin and pancreas
C. Intestine and mammary gland
D. Lung and spleen
E. All of these
The major constituent of the proteins of hair and keratin of skin:
A. Arginine
B. * Cysteine
C. Glycine
D. Arginine
E. None of these
The major site of urea synthesis is
A. Brain
B. Kidneys
C. * Liver
D. Muscles
E. Both B and C
The metabolism of protein is integrated with that of carbohydrate and fat through
A. * Oxaloacetate
B. Citrate
C. Isocitrate
D. Malate
E. A and B
The metabolism of protein is integrated with that of carbohydrate and fat through
A. * Oxaloacetate
B. Citrate
C. Isocitrate
D. Malate
E. Succinate
The milk protein in the stomach in an adult is digested by
A. * Pepsin
B. Rennin
C. HCl
D. Chymotrypsinogen
E. Both A and B
The milk protein in the stomach of the infants is digested by
A. Pepsin
B. Trypsin
C. Chymotrypsin
D. * Rennin
E. All of the above
The milk protein in the stomach of the infants is digested by
A.
B.
C.
D.
E.
1418.
A.
B.
C.
D.
E.
1419.
acid:
A.
B.
C.
D.
E.
1420.
A.
B.
C.
D.
E.
1421.
A.
B.
C.
D.
E.
1422.
A.
B.
C.
D.
E.
1423.
A.
B.
C.
D.
E.
1424.
A.
B.
C.
D.
E.
1425.
as
A.
B.
Pepsin
Trypsin
Chymotrypsin
* Rennin
A and D
The milk protein in the stomach of theinfants is digested by
Pepsin
Trypsin
Chymotrypsin
* Rennin
Both A and D
The negative nitric balance can be caused by the deficit of the following amino
Serine
Tyrosine
* Leucine
Glycine
Alanine
The neutral amino acids for absorption need
TPP
* B6 – PO4
NAD+
NADP+
FAD
The neutral amino acids for absorption need
TPP
* B6 – PO4
NAD+
NADP+
FAD
The only correct statement about chymotrypsin is
It is formed from trypsin
Carboxypeptidase converts trypsin into chymotrypsin
* Its optimum pH is around 7
It hydrolyses peptide bonds involving basic amino acids
Its optimum pH is around 4
The only correct statement about chymotrypsin is
It is formed from trypsin
Carboxypeptidase converts trypsin into chymotrypsin
* Its optimum pH is around 7
It hydrolyses peptide bonds involving basic amino acids
None of the above
The percentage of food nitrogen that is retained in the body represents
Digestibility coefficient
Biological value of proteins
Protein efficiency ratio
* Net protein utilisation
All of these
The percentage of ingested protein/nitrogen absorbed into blood stream is known
Net protein utilisation
Protein efficiency ratio
1426.
1427.
1428.
1429.
1430.
1431.
1432.
1433.
1434.
C. * Digestibility coefficient
D. Biological value of protein
E. All of these
The percentage of nitrogen retained in the body after absorption of diet represents
A. Digestibility coefficient of proteins
B. * Biological value of proteins
C. Protein efficiency ratio
D. Net protein utilisation
E. All of these
The pH of gastric juice become low in
A. Hemolytic anemia
B. * Pernicious anemia
C. Both (A) and (B)
D. Jaundice
E. None of these
The pH of gastric juice become low in
A. Hemolytic anemia
B. * Pernicious anemia
C. Both (A) and (B)
D. Gastritis
E. None of these
The recommended daily allowance (RDA) of proteins for an adult man is
A. * 70 gms
B. 50 gms
C. 40 gms
D. 30 gms
E. 200 gms
The symptom of ammonia intoxication includes
A. * Blurring of vision
B. Constipation
C. Mental confusion
D. Diarrhoea
E. All of these
The symptom of ammonia intoxication includes
A. * Blurring of vision
B. Constipation
C. Mental confusion
D. Diarrhea
E. All of these
The third active process for amino acids transport involves
A. Acidic amino acids
B. Basic amino acids
C. * Neutral amino acids
D. Sulphur containing amino acids
E. All of these
The third active process for amino acids transport involves
A. Acidic amino acids
B. Basic amino acids
C. * Neutral amino acids
D. Sulphur containing amino acids
E. C and D
The transaminase activity needs the coenzyme:
A.
B.
C.
D.
E.
ATP
* B6 – PO4
FAD+
NAD+
TPP
1435.
The transport of amino acids regulated by active processes of different numbers:
A. 1
B. 2
C. * 3
D. 4
E. 10
1436.
The transport of amino acids regulated by active processes of different numbers:
A. 1
B. 2
C. * 3
D. 4
E. None of the above
1437.
The unwanted amino acids abstracted from the tissues are either used up by the
tissue or in the liver converted into
A. Ammonia
B. * Urea
C. Ammonium salts
D. Uric acid
E. All of these
1438.
The useful reagent for detection of amino acids is
A. Molisch reagent
B. Dichlorophenol Indophenol
C. * Ninhydrin
D. Biuret
E. All of these
1439.
The zymogen from trypsinogen of pancreatic juice is converted to active trypsin
by
A. Peisin
B. Enterocrinin
C. * Enterokinase
D. Rennin
E. HCl
1440.
The zymogen from trypsinogen of pancreatic juice is converted to active trypsin
by
A. Peisin
B. Enterocrinin
C. * Enterokinase
D. Rennin
E. B and C
1441.
The ?-ketoacid is decarboxylated by H2O2 forming a carboxylic acid with one
carbon atom less in the absence of the enzyme:
A. * Catalase
B. Decarboxylase
C. Deaminase
D. Phosphatase
E. Both A and B
1442.
To endopeptidases belong all below-mentioned enzymes, except:
A.
B.
C.
D.
E.
1443.
A.
B.
C.
D.
E.
1444.
A.
B.
C.
D.
E.
1445.
A.
B.
C.
D.
E.
1446.
A.
B.
C.
D.
E.
1447.
A.
B.
C.
D.
E.
1448.
is
A.
B.
C.
D.
E.
Pepsin
Elastase
* Carboxypeptidase
Chemotrypsin
Trypsin
Transamination is a
Irreversible process
* Reversible process
Both (A) and (B)
Removal of CO2
None of these
Transcortins are
* Mucoproteins
Glycoproteins
Metalloproteins
Lipoproteins
None of the above
Transmethylation of guanido acetic acid gives
* Creatine phosphate
Creatinine
Choline
n-methyl nicotinamide
All of these
Transmethylation of guanido acetic acid gives
* Creatine phosphate
Creatinine
Choline
n-methyl nicotinamide
None of these
Tryptophan could be considered as precursor of
* Melanotonin
Thyroid hormones
Melanin
Epinephrine
All of these
Vitamin required for the conversion of hydroxyphenylpyruvate to homogentisate
Folacin
Cobalamin
Ascorbic acid
* Niacin
Cholecalciferol
1449.
What biologically active substance is formed in the process of decarboxylation of
5-hydroxytryptophane?
A. Corticosterone
B. Thyroxine
C. * Serotonine
D. Histamine
E. Anserine
1450.
What chemical compound is formed in reaction of amino acids transamination?
A. Ammonia.
B. H2O.
C. * ?-Keto-acid.
D. Pyruvate.
E. None of these
1451.
What contents of free hydrochloric acid is in the gastric juice?
A. 10-20 mmol/l
B. * 20-40 mmol/l
C. 40-60 mmol/l
D. 60-80 mmol/l
E. 80-100 mmol/l
1452.
What disease is proved by increase of AsAT in blood?
A. Parotiditis
B. Gastritis
C. Pancreatitis
D. * Cardiac infarction
E. Pneumonia
1453.
What is the name of the cofactor for AST, ALT, or any other transamination
reaction?
A. NAD+
B. Acetyl CoA
C. * Pyridoxal phosphate (PLP)
D. FADH2
E. NADPH
1454.
When egg albumin is heated till it is coagulated, the secondary and tertiary
structures of the proteins are completely lost resulting in a mixture of randomly arranged
A. Dipeptide chains
B. Tripeptide chains
C. * Polypeptide chains
D. All of these
E. None of these
1455.
Which amino acid is a lipotropic factor?
A. Lysine
B. Leucine
C. Tryptophan
D. * Methionine
E. All of these
1456.
Which amino acid is a lipotropic factor?
A. Lysine
B. Lecuine
C. Tryptophan
D. * Methionine
E. A and D
1457.
Which among the following is a nutritionally essential amino acid for man ?
A. Alanine
B. Glycine
C. Tyrosine
D. * Tryptophan
E. Both A and D
1458.
Which among the following is an essential amino acid?
A. Cysteine
B. * Leucine
C. Tyrosine
D. Aspartic acid
1459.
1460.
1461.
1462.
1463.
1464.
1465.
1466.
1467.
E. Both B and D
Which compounds are formed during the oxidative deamination of amino acids?
A. * Keto acid and ammonia.
B. Saturated fatty acid and ammonia.
C. Unsaturated fatty acid and ammonia.
D. Keto acid and H2O.
E. A and D.
Which enzyme activates the trypsinogen?
A. Chymotrypsin
B. Carboxypeptidase
C. * Enterokinase
D. Trypsin
E. Aminopeptidase
Which enzyme cleaves proteins in the stomach?
A. Trypsin
B. Chymotrypsin
C. Carboxypeptidase
D. Enterokinase
E. * Pepsin
Which enzyme takes part in oxidative deamination of amino acids?
A. Pyridine-linked oxidase.
B. * Pyridine-linked dehydrogenase.
C. Pyridine-linked carboxypeptidase
D. Pyridine-linked transferase.
E. B and D
Which of the amino acid produces a vasodilator on decarboxylation?
A. Glutamin acid
B. * Histidine
C. Ornithine
D. Cysteine
E. C and D
Which of the amino acid produces a vasodilator on decarboxylation?
A. Glutamic acid
B. * Histidine
C. Ornithine
D. Cysteine
E. Alanine
Which of the following is an amino acid that is found in proteins?
A. Adenosine
B. Adenine
C. * Alanine
D. Linoleic acid
E. Creatine
Which of the following is an essential amino acid?
A. Glutamine
B. Proline
C. * Methionine
D. Cysteine
E. Asparagine
Which of the following is an essential amino acid?
A. Glutamine
B. Proline
C. Methionine
D. Cysteine
E. Asparagine
1468.
Which one of the following is an essential amino acid?
A. Arginine
B. Tyrosine
C. * Phenylalanine
D. Proline
E. B and C
1469.
Which pathological component appears in the gastric juice in cancer of the
stomach?
A. * Lactic acid
B. Hydrochloric acid
C. Acetic acid
D. Sulfuric acid
E. Citric acid
1470.
Which pathological component appears in the gastric juice in cancer of the
stomach?
A. * Lactic acid
B. Hydrochloric acid
C. Acetic acid
D. Sulfuric acid
E. Citric acid
1471.
Which vitamins take part in deamination of amino acids?
A. B6
B. B3
C. * B5
D. B1
1472.
With decarboxylation of histidine is formed:
A. Tyramine
B. * Histamine
C. Putrescine
D. Cadaverine
E. Serotonine
1473.
Zymogen is
A. An intracellular enzyme
B. Serum enzyme
C. A complete extracellular enzyme
D. * An inactivated enzyme
1474.
All of t_________ provides one of the N atoms in urea synthesized by the urea
cycle, while ___________ is a product of the urea cycle.
A. NH3 ; aspartate
B. NH3 ; carbamate
C. * Aspartate ; fumarate
D. Fumarate ; aspartate
E. Carbamate ; fumarate
1475.
________ contain(s) nitrogen
A. * Amino acids
B. Nucleotides
C. Creatine phosphate
D. All of the above
E. None of the above
1476.
A.
B.
C.
D.
E.
1477.
A.
B.
C.
D.
E.
1478.
A.
B.
C.
D.
E.
1479.
A.
B.
C.
D.
E.
1480.
A.
B.
C.
D.
E.
1481.
A.
B.
C.
D.
E.
1482.
A.
B.
C.
D.
E.
1483.
A.
B.
C.
D.
E.
1484.
A.
B.
C.
A coenzyme required for the synthesis of glycine from serine is
ATP
Pyridoxal phosphate
* Tetrahydrofolate
NAD
FAD
A compound serving a link between citric acid cycle and urea cycle is
Malate
Citrate
Succinate
* Fumarate
Ornithine
A dietary deficiency of tryptophan and nicotinate leads to
Beri Beri
Xerophthalmia
Anemia
* Pellegra
Rickets
A phosphoprotein present in egg is
Casein
Albumin
Ovoglobulin
Ovovitellin
Ihtulin
A positive nitrogen balance occurs
* In growing infant
Following surgery
In advanced cancer
In kwashiorkar
In old year
Abnormal chain of aminoacids in sickle cell anemia is
?-chain
B-chain
* C?-chain
-chain
-chain
Activity of ceruloplasmin shown in vitro:
Reductase
* Hydrolase
Ligase
Oxidase
Transferases
Alanine can be synthesized from
Glutamate and ?-ketoglutarate
* Pyruvate and glutamate
Pyruvate and ?-ketoglutarate
Asparate and ?-ketoglutarate
None of the above
All amino acids have one asymmetric carbon atom, except
Arginine
Aspargine
* Histidine
1485.
1486.
1487.
1488.
1489.
1490.
1491.
1492.
1493.
D. Glycine
E. Valine
All followings are ketogenic aminoacids, except
A. Leucine
B. Isoleucine
C. * Phenyl alanine
D. Glycine
E. Lysine
All of the following are required for synthesis of alanine except
A. Pyruvate
B. ?-ketoglutarate
C. Glutamate
D. Pyridoxal phosphate
E. * None of the above
All of the following are required for synthesis of glutamine except
A. Glutamate
B. Ammonia
C. * Pyridoxal phosphate
D. ATP
E. None of the above
All of the following statements about aspartate are true except
A. It is non-essential amino acid
B. It is a dicarboxylic amino acid
C. It can be synthesized from pyruvate and glutamate
D. * It can be converted into asparagine
E. None of the above
All the following statements about albinism are correct, except
A. Tyrosine hydroxylase (tyrosinase) is absent or deficient in melanocytes
B. Skin is hypopigmented
C. * It results in mental retardation
D. Eyes are hypopigmented
E. A, B, D are correct
All the following statements about pepsin are correct, except
A. It is smaller than pepsinogen
B. It is formed by the action of HCl on its precursor
C. Its optimum pH is 1.0–2.0
D. * It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
E. Its optimum pH is 10–12
All the following statements about phenylketonuria are correct, except
A. * Phenylalanine cannot be converted into tyrosine
B. Urinary excretion of phenylpyruvate and phenyllactate is increased
C. It can be controlled by giving a lowphenylalanine diet
D. It leads to decreased synthesis of thyroid hormones, catecholamines and melanin
E. It leads to increased synthesis of insulin, catecholamines and homogentosonic
acid
Allosteric inhibitor of glutamate dehydrogenase is
A. ATP
B. ADP
C. AMP
D. * GDP
E. AMP
Allsoteric activator of glutamate dehydrogenase is
A.
B.
C.
D.
E.
1494.
A.
B.
C.
D.
E.
1495.
A.
B.
C.
D.
E.
1496.
A.
B.
C.
D.
E.
1497.
A.
B.
C.
D.
E.
1498.
A.
B.
C.
D.
E.
1499.
A.
B.
C.
D.
E.
1500.
A.
B.
C.
D.
E.
1501.
A.
B.
C.
* ADP
GTP
ADP and GDP
AMP and GMP
ATP
Along with CO2, NH3 and ATP the aminoacid that is needed in urea cycle is
Alanine
Isoleucine
* Aspartate
Glycine
Valine
Amino acids excepting histidine are not good buffering agents in cell because
They exist as zwitter ions
* Their pk and not in the physiological pH of a cell
Only Histidine has pk of its R group at 6.0 unlike the others which have at a
different pH
None of these
All of the above
Amino acids, monosaccharrides, glycerol and fatty acids are:
Transported in the lymph to all the lymph nodes in the body
All hormones
Products of carbohydrate metabolism
Enzymes
* End products of digestion
Ammonia is transported from muscles to liver mainly in the form of
Free ammonia
Glutamine
Asparagine
* Alanine
?-ketoglutarate
An amino acid not containing the usual— COOH group is
Alanine
Tryptophan
Methionine
* Taurine
Serine
An amino acid not involved in urea cycle is
Arginine
* Histidine
Ornithine
Citrulline
Only C and D
An amino acid which contains a disulphide bond is
Lysine
Methionine
Homocysteine
* Cystine
None of the above
An exopeptidase is
Trypsin
Chymotrypsin
Elastase
D. * Peptidase
E. Phospholipase
1502.
An important reaction for the synthesis of amino acid from carbohydrate
intermediates is transamination which requires the cofactor:
A. Thiamin
B. Riboflavin
C. Niacin
D. * Pyridoxal phosphate
E. Pantotenic acid
1503.
An organ which is extremely sensitive to ammonia toxicity is
A. Liver
B. * Brain
C. Kidney
D. Heart
E. Lung
1504.
As a result of amino acids decarboxylation in the organism are formed:
A. Ammonia, urea, creatine
B. * Amines, diamines
C. Polypeptides, uric acid
D. Dipeptides, xanthine
E. Allantion, indican
1505.
Branched chain amino acids are
A. Cysteine and cystine
B. Tyrosine and Tryptophan
C. Glycine and Serine
D. * Valine, Leucine and Isoleucine
E. Serin ans glycine
1506.
By decarboxylation of histidine are formed:
A. Tyramine
B. * Histamine
C. Putrescine
D. Cadaverine
E. Serotonine
1507.
C Splitting polymers into absorbable monomers in the GI tract
A. * Transport of nutrient molecules from the intestine to cells
B. Intracellular change of nutrient molecules into essential intracellular nutrients
C. Secretion of insulin and glucagon
D. Absorption of nutrient molecules into the body
1508.
Carbamoyl phosphate required for urea synthesis is formed in
A. Cytosol
B. * Mitochondria
C. Both (A) and (B)
D. None of these
E. Only A
1509.
Chymotrypsin is specific for peptide bonds containing
A. * Uncharged amino acid residues
B. Acidic amino acids
C. Basic amino acid
D. Small amino acid residues
E. None of the above
1510.
Clinical features of Kwashiorkor include all of the following except
A. Mental retardation
B.
C.
D.
E.
Muscle wasting
Oedema
* Anaemia
A and B
1511.
Coenzyme of amino acids decarboxylases is:
A. Thymidine diphosphate
B. Favin adenine dinucleotide
C. Favin mononucleotide
D. HS-CoA
E. * PALP
1512.
Combine the correct organism with the type of excretion of ammonia it uses.
Draw lines between.
A. Birds; Urea
B. * Humans; Uric acid
C. Fishes; Ammonia (ammonium ion)
D. Birds; Uric acid
E. Fishes; Uric acid
1513.
Consumption of raw eggs can cause deficiency of
A. * Calcium
B. Lipoic acid
C. Biotin
D. Vitamin A
E. Vitamin B2
1514.
Cysteine can be synthesized from methionine and
A. * Serine
B. Homoserine
C. Homocysteine
D. Threonine
E. Cystein
1515.
Cysteine has the formula: a. CH3SH; b. H2N—CH2—COOH c. HS—CH2—
CH(NH2)—COOH d. S—CH2—CH(NH2)—COOH S—CH2—CH(NH2)—COOH
A. d
B. c
C. * b
D. a
E. None of the above
1516.
Cystine is synthesized from
A. * Cysteine
B. Methionine
C. Arginine
D. Leucine
E. Valine
1517.
Cystinuria results from inability to
A. Metabolise cysteine
B. Convert cystine into cysteine
C. Incorporate cysteine into proteins
D. * Reabsorb cystine in renal tubules
E. Only A
1518.
Daily excretion of nitrogen by an adult man is about
A. 15–20 mg
B. 1.5–2 gm
C. 5–10 gm
1519.
1520.
1521.
1522.
1523.
1524.
1525.
1526.
1527.
D. 15–20 gm
E. * 3,5-4 gm
Denitrification involves reduction of nitrate, and the production of _______.
A. N2
B. NO
C. N2O
D. * All of the above
E. More than one of the above, but not all
Digestion of proteins:
A. Consumes water (hydrolysis) and amino acids
B. Consumes water (hydrolysis) and releases amino acids
C. * Releases water (dehydration) and amino acids
D. Releases water (dehydration) and consumes amino acids
E. None of the above
E None of the above
A. Metabolism of consumed foods and vitamins
B. Absorption of many of the digested nutrients
C. * Mixing of the gastric contents to form chyme
D. Secretion of alkaline enzymes
Egg is poor in
A. * Essential amino acids
B. Carbohydrates
C. Avidin
D. Biotin
E. None of the above
Egg is rich in all of the following except
A. Cholesterol
B. Saturated fatty acids
C. * Ascorbic acid
D. Calcium
E. Unsaturated fatty acids
Excess amino acids in the body are broken down to form urea in
A. Kidney
B. * Liver
C. Spleen
D. Pancreas
E. Stomach
For biosynthesis of proteins
A. * Amino acids only are required
B. Amino acids and nucleic acids only are required
C. Amino acid, nucleic acids and ATP only are required
D. Amino acids, nucleic acids, ATP, GTP, enzymes and activators are required
E. All are correct
For vegetarians, pulses are an important source of
A. Carbohydrates
B. * Proteins
C. Fat
D. Iron
E. All of the above
Free ammonia is released during
A. * Oxidative deamination of glutamate
B. Catabolism of purines
1528.
1529.
1530.
1531.
1532.
1533.
1534.
1535.
C. Catabolism of pyrimidines
D. All of these
E. Only C
Functions of the liver
A. Acts as a storehouse for certain vitamins and iron
B. Synthesizes fibrinogen and prothrombin for coagulation
C. * Synthesis of the serum albumin essential for blood colloid osmotic pressure and
fluid balance
D. Regulates blood levels of glucose, ketone bodies and fatty acids
E. Destroys bacteria that enter the blood from the intestine before reaching the
general circulation
Gastrin, which is secreted by stomach cells, functions to:
A. Inhibit the production of hydrochloric acid
B. Increase the secretions of the gastric glands
C. * Change pepsin into pepsinogen
D. Initiate the cephalic phase of digestion
E. Inhibit the secretory activities of the pancreas, liver and small intestine
Glycine can be synthesized from
A. * Serine
B. Choline
C. Betaine
D. All of these
E. Methionine
Glycine is not required for the formation of
A. Taurocholic acid
B. Creatine
C. Purines
D. * Pyrimidines
E. Glutation
Histamine is formed from histidine by
A. Deamination
B. Dehydrogenation
C. * Decarboxylation
D. Carboxylation
E. Oxidation
Histidine is converted to histamine through the process of
A. Transamination
B. * Decarboxylation
C. Oxidative deamination
D. Urea cycle
E. Krebs cycle
How many different amino acids are necessary for our protein production?
A. 15
B. 18
C. * 20
D. 25
E. 10
In carcinoid syndrome the argentaffin tissue of the abdominal cavity overproduce
A. Serotonin
B. Histamine
C. * Tryptamine
D. Tyrosine
E. None of the above
1536.
In humans, NH3 is detoxified in liver as
A. Creatinine
B. Uric acid
C. * Urea
D. Uronic acid
E. Amino acid
1537.
In the following reaction, Alanine acts as a H- H| | H- N– –COO—— H- N– –
COOH- C- C| |CH- CH
A. Acid
B. * Base
C. Zwitter ion
D. None of these
E. Only C are correct
1538.
In the mouth:
A. Food is propelled primarily by peristalsis
B. * The saliva is used to lubricate and dissolve food
C. The front teeth are called incisors
D. All of the above
E. B and C only
1539.
In the synthesis of 1 molecule of urea in the Kreb’s Hanseleit cycle, the number of
ATPs required is
A. 1
B. * 2
C. 3
D. 4
E. 5
1540.
In urea synthesis, the amino acid functioning solely as an enzyme activator:
A. * N-acetyl glutamate
B. Ornithine
C. Citrulline
D. Arginine
E. Serine
1541.
Increased serum alanine during fasting is due to
A. Breakdown of muscle proteins
B. * Decreased utilization of non essential amino acids
C. Leakage of aminoacids to plasma
D. Impaired renal function
E. Only C
1542.
Isoelectric pH of an amino acid is that pH at which it has a
A. Positive charge
B. Negative charge
C. * No charge
D. None of these
E. All of the above
1543.
Kwashiorkor occurs when the diet is severely deficient in
A. Iron
B. Calories
C. * Proteins
D. Essential fatty acids
E. Ca++
1544.
Maple syrup urine diseases is an inborn error of metabolism of
A.
B.
C.
D.
E.
Sulphur-containing amino acids
Aromatic amino acids
* Branched chain amino acids
Dicarboxylic amino acids
None of the above
1545.
Mechanism by which NH3 is removed from the kidneys is
A. Urea formation
B. Uric acid formation
C. * Creatinine formation
D. None of these
E. All of the above
1546.
Methionine is synthesized in human body from
A. Cysteine and homoserine
B. Homocysteine and serine
C. * Cysteine and serine
D. None of these
E. Only A
1547.
Milk is a good source of
A. Proteins, calcium and iron
B. Proteins, calcium and ascorbic acid
C. Proteins, lactose and retinol
D. * Proteins, lactose and essential fatty acids
E. All of the above
1548.
Most of the ammonia released from L- amino acids reflects the coupled action of
transaminase and
A. * L-glutamate dehydrogenase
B. L-amino acid oxidase
C. Histidase
D. Serine dehydratase
E. Only D
1549.
Name the matter in the urine, which is a test of intensivity of protein putrefaction
processes in the intestine:
A. Urates
B. Urea
C. Creatinine
D. * Indican
E. Lactic acid
1550.
Natural L-isomers of amino acids are absorbed from intestine by
A. Passive diffusion
B. Simple diffusion
C. Faciliated diffusion
D. * Active process
E. None of the above
1551.
Naturally occurring amino acids have
A. L-Configuration
B. D-Configuration
C. * DL-Configuration
D. None of these
E. B-Configuration
1552.
NH3 is detoxified in brain chiefly as
A. * Urea
B. Uric acid
C. Creatinine
D. Glutamine
E. Cesteine
1553.
NH3 is removed from brain mainly by
A. Creatinine formation
B. Uric acid production
C. * Urea formation
D. Glutamine formation
E. None of the above
1554.
Non-protein amino acids are
A. * Ornithine
B. ?-alanine
C. ?-amino butyric acid
D. All of these
E. Serine
1555.
Number of amino acids present in the plant, animal and microbial proteins:
A. * 20
B. 80
C. 150
D. 200
E. 101
1556.
One of the following amino acid is solely ketogenic:
A. * Lysine
B. Alanine
C. Valine
D. Glutamate
E. Arginine
1557.
Only one type of digestive juice contains carbohydrate, protein and fat-digesting
enzymes. Which one is it?
A. * Pancreatic juice
B. Saliva
C. Bile
D. Intestinal juice
E. Gastric juice
1558.
Pancreatic juice contains the precursors of all of the following except
A. * Trypsin
B. Chymotrypsin
C. Carboxypeptidase
D. Aminopeptidase
E. Elastase
1559.
Patient has positive nitric balance. The reason of this can be:
A. Starvation
B. Tuberculosis
C. * Pregnancy
D. Malignant neoplasms
E. AIDS
1560.
Patient on a vegetarian diet has negative nitric balance, hyperproteinemia,
affection of colloid-osmotic pressure and water-salt metabolism by normal function of
alimentary canal. This was caused by:
A. * Monotonous protein nutrition
B. Monotonous carbohydrate nutrition
C. Lack of unsaturated fatty acids
D. Lack of phospholipids in food
E. Lack of vitamins in food
1561.
Patient with enterocolitis has affected protein adoption. What mechanism of
amino acids absorption is affected?
A. Pinocytosis
B. Primary active transport
C. Simple diffusion
D. * Secondary sodium-dependent transport
E. Phagocytosis
1562.
Pepsin acts on denatured proteins to produce
A. Proteases and peptones
B. * Polypeptides
C. Peptides
D. Dipeptides
E. Glicerol
1563.
Pepsinogen is converted to active pepsin by
A. * HCl
B. Bile salts
C. Ca++
D. Enterokinase
E. Lipase
1564.
Physiologically active configuration of amino acids:
A. * L
B. D
C. For some amino acids it is either of two
D. Neither L nor D
E. C
1565.
Positive nitrogen balance is seen in
A. Starvation
B. Wasting diseases
C. * Growing age
D. Intestinal malabsorption
E. All of the above
1566.
Proteins that carries Iron into different tissues is
A. Ceruloplasmin
B. * Trans cortin
C. Mucoproteins
D. Glycoproteins
E. Lipoprotein
1567.
Pyridoxal phosphate, what is it?
A. It’s essential since our body can produce it itself
B. It’s essential since our body cannot produce it itself and it needs to be taken up
from the diet
C. It is a receptor molecule
D. * It is a very important co-enzyme in for instance transamination reactions
E. All of the above
1568.
Renin converts casein to paracasein in presence of
A. * Ca++
B. Mg++
C. Na+
D. K+
E. Fe++
1569.
Secretin produced by the mucosa of the duodenum is stimulated by:
A. Distention of the stomach
B. Large quantities of bile
C. A fatty chyme
D. * Acidity of the chyme
E. None of the above
1570.
Sulphur-containing amino acid is
A. Glutathione
B. Chondroitin sulphate
C. * Homocysteine
D. Tryptophan
E. Histidin
1571.
Sulphur-containing amino acid is
A. Glutathione
B. Chondroitin sulphate
C. * Homocysteine
D. Tryptophan
E. Histidin
1572.
The 2 nitrogen atoms in urea are contributed by
A. Ammonia and glutamate
B. Glutamine and glutamate
C. * Ammonia and aspartate
D. Ammonia and alanine
E. Ammonia and Glutamine
1573.
The absorption of intact protein from the gut in the foetal and newborn animals
takes place by
A. Pinocytosis
B. Passive diffusion
C. Simple diffusion
D. * Active transport
E. A and B
1574.
The acceptor of amino group in the processes of transamination is:
A. Pyruvate
B. Oxaloacetate
C. *
D. Fumarate
E. Dioxyacetonephosphate
1575.
The activators of trypsinogen are:
A. Hydrochloric acid
B. * Chymotrypsin
C. Enterokinase
D. Aminopeptidases
E. Carboxypeptidase
1576.
The amino acid containing an indole ring:
A. Tryptophan
B. Arginine
C. Threonine
D. * Phenylalanine
E. Valine
1577.
The amino acid that undergoes oxidative deamination at significant rate is
A. Alanine
B. Aspartate
C. * Glutamate
D. Glutamine
E. Serin
1578.
The amino acid which contains an indole group is
A. Histidine
B. Arginine
C. lycine
D. * Tryptophan
E. Cysteine
1579.
The amino acid which contains an indole group is
A. Histidine
B. Arginine
C. lycine
D. * Tryptophan
E. Cysteine
1580.
The amino acid which has a pK near 4 and thus is negatively charged at pH 7 is
A. * Alanine
B. Glutamic acid
C. Glutamine
D. Aspargine
E. None of the above
1581.
The amino acids in which the R groups have a net positive charge at pH 7.0 are
A. Lysine, Arginine, Histidine
B. Lysine, Aspargine
C. * Histidine, Aspargine
D. Glutamine, Arginine
E. Only D
1582.
The amount of urea in patient's urine is normal. Which of the listed figures are
true in this case?
A. 10-15 g
B. 20-40 g
C. 10-35 g
D. * 25-30 g
E. 50-60 g
1583.
The body protein after eighteen years
A. Remains unchanged
B. Is decomposed only slightly at intervals of one month
C. Is in a constant state of flux
D. * Is used only for energy requirement
E. None of the above
1584.
The bond in proteins that is not hydrolysed under usual conditions of
denaturation:
A. Hydrophobic bond
B. Hydrogen bond
C. Disulphide bond
D. * Peptide bonds
E. Hydrophobic interaction
1585.
The catalytic triad of most serine proteases contains an Asp, His and Ser residue.
Which of the following is true?
A. The Asp residue is used in an acid catalyzed attack on the peptide bond.
B. The His residue is responsible for the substrate specificity of Trypsin.
C. * The Ser residue is used in a nucleophilic attack on the peptide bond.
D. The Asp residue is responsible for the substrate specificity of Trypsin.
E. None of the above.
1586.
The cleavage of trypsinogen to form active trypsin
A. Ocurs in the small intestine.
B. Can be catalyzed by trypsin.
C. Ocurs in the pancreas.
D. Can be catalyzed by chymotrypsin.
E. * The first two choices are both correct.
1587.
The cleavage specificity of trypsin, chymotrypsin, and elastase depend in part on:
A. The proximity of Ser 195 to the specificity pocket.
B. The size, shape, and charge of the specificity pocket.
C. The distance between the oxyanion hole and the specificity pocket.
D. * The presence of a low-barrier hydrogen bond in the specificity pocket.
E. The absence of water in the specificity pocket.
1588.
The compound having the formula H2N—CO—NH—CH2—CH2—CH2—CH—
COOH is NH2
A. * Lysine
B. Glutamine
C. Serine
D. Citrulline
E. Only C
1589.
The compound used by fish for the purpose of disposing of excess nitrogen is
A. * Uric acid
B. Urea
C. Ammonia
D. Aspartate
E. Fumarate
1590.
The concentration of urea in the blood of healthy man is:
A. 10-12 mM/l
B. 12-20 mM/l
C. 1-2 mM/l
D. * 3-8 mM/l
E. 15-18 mM/l
1591.
The concentration of urea is highest in
A. Renal vein
B. * Hepatic portal vein
C. Dorsal aorta
D. Hepatic vein
E. Only C
1592.
The concentration of urea is least in
A. Renal artery
B. * Renal vein
C. Post canal
D. Dorsal aorta
E. Hepatic portal vein
1593.
The defective enzyme in histidinemia is
A. Histidine carboxylase
B. Histidine decarboxylase
C. * Histidase
D. Histidine oxidase
E. None of the above
1594.
The end product of protein digestion in G.I.T. is
A.
B.
C.
D.
E.
1595.
A.
B.
C.
D.
E.
1596.
A.
B.
C.
D.
E.
1597.
A.
B.
C.
D.
E.
1598.
A.
B.
C.
D.
E.
1599.
A.
B.
C.
D.
E.
1600.
A.
B.
C.
D.
E.
1601.
A.
B.
C.
D.
E.
1602.
A.
B.
C.
D.
Dipeptide
Tripeptide
Polypeptide
* Amino acid
Peptide
The enzyme carbamoyl phosphate synthetase requires
* Mg++
Ca++
Na+
K+
F+
The enzyme trypsin is specific for peptide bonds of
Basic amino acids
Acidic amino acids
* Aromatic amino acids
Next to small amino acid residues
Fatty acids
The enzymes of urea synthesis are found in
Mitochondria only
Cytosol only
* Both mitochondria and cytosol
Nucleus
Lysosoms
The following enzyme of urea cycle is present in cytosol:
Argininosuccinic acid synthetase
Argininosuccinase
Arginase
* All of these
Ornithin-carbamoilphosphatetransferase
The following has the highest protein efficiency ratio:
Milk proteins
Egg proteins
* Meat proteins
Fish proteins
All of the above
The main site of urea synthesis in mammals is
* Liver
Skin
Intestine
Kidney
Lung
The main sites for oxidative deamination are
* Liver and kidney
Skin and pancreas
Intestine and mammary gland
Lung and spleen
Duodenum and spleen
The major constituent of the proteins of hair and keratin of skin:
Arginine
* Cysteine
Glycine
Asparagine
1603.
1604.
1605.
1606.
1607.
1608.
1609.
1610.
1611.
E. Glutamic acid
The major end product of protein nitrogen metabolism in man is
A. Glycine
B. Uric acid
C. * Urea
D. NH3
E. Serine
The major site of urea synthesis is
A. Brain
B. Kidneys
C. * Liver
D. Muscles
E. Lung
The most important function of the large intestine is:
A. Absorption of water and electrolytes
B. Secretion of enzymes
C. * Digestion of incompletely digested foods
D. Removal of toxic substances
E. All of the above are equally important
The number of ATP required for urea synthesis is
A. 0
B. 1
C. * 2
D. 3
E. 12
The only correct statement about chymotrypsin is
A. It is formed from trypsin
B. * Carboxypeptidase converts trypsin into chymotrypsin
C. Its optimum pH is around 7
D. It hydrolyses peptide bonds involving basic amino acids
E. All of the above
The optimal pH for the enzyme chymotrypsin is
A. 2.0
B. 4.0
C. 6.0
D. 8.0
E. * 7,0
The optimal pH for the enzyme pepsin is
A. 1.5–2.5
B. * 4.0–5.0
C. 5.2–?6.0
D. 5.8–6.2
E. 6,0 – 8,0
The optimal pH for the enzyme rennin is
A. 2.0
B. 4.0
C. 8.0
D. * 5.0
E. 7,0
The oxidative deamination of the amino acid alanine in muscle produces:
A. * One molecule of pyruvic acid and a molecule of ammonia
B. One molecule of pyruvic acid and a molecule of carbon dioxide
C. One molecule of pyruvic acid and another amino acid
D. One molecule of pyruvic acid and a molecule of water
E. One molecule of pyruvic acid and a molecule of urea
1612.
?The pancreatic enzymes, trypsin, chymotrypsin and elastase all have:
A. The same catalytic triad at their active sites.
B. Similar sequences and tertiary structures.
C. * The same catalytic mechanism.
D. Smilar processing pathways from inactive zymogens.
E. All of the above choices are correct
1613.
The pH of an amino acid depends
A. * Optical rotation
B. Dissociation constant
C. Diffusion coefficient
D. Chain length
E. None of the above
1614.
The pH of an amino acid depends
A. * Optical rotation
B. Dissociation constant
C. Diffusion coefficient
D. Chain length
E. None of the above
1615.
The reservoir for nitrogen is
A. The atmosphere.
B. Rocks.
C. Ammonia.
D. Nitrates.
E. * Amino acids.
1616.
The small intestine is the main site of absorption of:
A. Carbohydrates absorbed as monosacchorides
B. Carbohydrates absorbed as amino acids by active transport
C. Fats absorbed into lacteals of the lymphatic system
D. * Proteins absorbed as small molecules or proteoses
E. A and C only
1617.
The sodium bicarbonate in pancreatic juice helps to raise the pH of chyme. What
substance originally lowered the pH of chyme?
A. Chyle
B. H2CO3
C. * HCL
D. Alkali
E. Base
1618.
The synthesis of urea finishes with:
A. Condencation of citrulline from NH3
B. * Fermentative hydrolysis of arginine to ornithine and urea
C. Synthesis of arginine from citrulline
D. Oxidation to ornithine and urea with participation of O2 and arginine
E. Oxidation of arginine with participation of O2 to ornithine and urea
1619.
The useful reagent for detection of amino acids is
A. Molisch reagent
B. Dichlorophenol Indophenol
C. * Ninhydrin
D. Biuret
E. None of the above
1620.
The useful reagent for detection of amino acids is
A. Molisch reagent
B. Dichlorophenol Indophenol
C. * Ninhydrin
D. Biuret
E. None of the above
1621.
Transfer of the carbamoyl moiety of carbamoyl phosphate to ornithine is catalysed
by a liver mitochondrial enzyme:
A. Carbamoyl phosphate synthetase
B. * Ornithine transcarbamoylase
C. N-acetyl glutamate synthetase
D. N-acetyl glutamate hydrolase
E. Arginase
1622.
Trypsinogen is converted to active trypsin by
A. * Enterokinase
B. Bile salts
C. HCl
D. Mg2+
E. Colipase
1623.
Tyrosine could be considered as precursor of
A. Melanotonin
B. * Thyroid hormones
C. Melanin
D. Epinephrine
E. Insulin
1624.
Urea is transported by
A. * Plasma
B. Blood
C. RBC
D. WBC
E. None af the above
1625.
What amino acid in the process of urea biosynthesis splits to urea and ornithine?
A. Leucine
B. Citrulline
C. * Arginine
D. Valine
E. Proline
1626.
What biologically active substance is formed in the process of decarboxylation of
5-hydroxytryptophane?
A. Corticosterone
B. Thyroxine
C. * Serotonine
D. Histamine
E. Anserine
1627.
What type of covalent bonds link the amino acids in a protein?
A. * Peptide bonds
B. Hydrogen bonds
C. Ionic bonds
D. Glycosidic bonds
E. Ester bonds
1628.
When branched chain amino acids are deaminated in muscle, the ammonia
produced is mostly:
A.
B.
C.
D.
E.
Converted into arginine and released from the muscle
* Converted into alanine and glutamine and released from the muscle
Converted into urea and released from the muscle
Ued to synthesise purines and pyrimidines in the muscle
Oxidised to form nitric oxide
1629.
Which of the following amino acids commonly acts as a nucleophilic group in
enzyme catalysed reaction mechanisms?
A. Serine
B. * Phenylalanine
C. Histidine
D. Valine
E. Tyrosine
1630.
Which of the following contributes nitrogen atoms to both purine and pyrimidine
rings?
A. * Aspartate
B. Carbamoyl phosphate
C. CO2
D. Glutamine
E. Fumarate
1631.
Which of the following is an amino acid that is found in proteins?
A. Adenosine
B. Adenine
C. * Alanine
D. Linoleic acid
E. Creatine
1632.
Which of the following is not a function of the pancreas?
A. Secretes insulin as well as glucagon into pancreatic duct
B. * Secretes alkaline juice which neutralizes chyme while chyme is stored in the
stomach
C. Secretes both endocrine and exocrine substances
D. Secretes lipase which acts on bile-emulsified fats to convert them to fatty acids
and glycerol
E. Secretes amylase which acts on starches to convert them to maltose
1633.
Which of the following is not an amino acid?
A. Glutamic acid
B. Aspartic acid
C. Glutamine
D. * Palmitic acid
E. Leucine
1634.
Which of the following reactions is carried out by species of Nitrobacter?
A. Nitrate _ N2
B. Nitrite _ nitrate
C. Nitrite-->ammonia
D. Nitrate _ nitrite
E. Ammonia _ nitrite
1635.
Which of the following takes place in the mouth?
A. Food is fashioned into a bolus
B. * Carbohydrate digestion begins
C. Food becomes partially liquified
D. All of the above
E. A and B only
1636.
Which of the followings gives a positive test for Ninhydrin?
A.
B.
C.
D.
E.
Reducing sugars
Triglycerides
* Alpha aminoacids
Esterified Fats
Vitamins
1637.
Which of the molecule(s) is/are the most common donators of amino groups
during transaminations?
A. Tyrosine
B. * Glutamate
C. Alanine
D. Glutamin
E. A and C
1638.
Which of these is false about “gastric juice?”
A. * Is highly acidic because of its HCL content
B. Contains the intrinsic factor for absorption of vitamin B12
C. Is controlled in part by a hormone called gastrin
D. Becomes neutralized in the duodenum by the action of sodium bicarbonate from
the pancreas
E. None of the above
1639.
Which one of the following is an essential amino acid?
A. Arginine
B. Tyrosine
C. * Phenylalanine
D. Proline
E. Ornitine
1640.
With which of the listed cycles is connected the cycle of urea formation?
A. PFC
B. * Tricarboxylic acid cycle
C. Gluconeogenesis
D. Glycolysis
E. Lipogenesis hese
Real life situation questions
1. A competitive inhibitor of an enzyme
A. Increases Km without affecting Vmax
B. Decreases Km without affecting Vmax
C. * Increases Vmax without affecting Km
D. Decreases Vmax without affecting Km
E. All of above
2. A competitive inhibitor of an enzyme is usually:
A. A highly reactive compound
B. A metal ion such as Hg2+ or Pb2+
C. * Structurally similar to the substrate
D. Water insoluble
E. A poison
3. A holoenzyme refers to the form of the enzyme__________________.
A. * That has the cofactor attached
B. That does not have the cofactor attached
C. That is normally inactive
D. None of the above
E. That has only prosthetic group
4. A key role of the hydroxyl group at position 6 in the purine ring in the formation of a
transition state by the enzyme adenosine deaminase is obtained by comparing a _______
inhibitor and a _______ inhibitor.
A. Competitive; noncompetitive
B. Transition state analog; normal substrate
C. Noncompetitive; transition state analog
D. * Competitive; transition state analog
E. All of the above
5. A molecule that has the same shape as the substrate of an enzyme would tend to
A. speed metabolism by guiding the enzyme to its substrate
B. speed metabolism because it would also be a catalyst
C. * speed metabolism by acting as a cofactor for the enzyme
D. save the cell energy by substituting for the substrate
E. slow metabolism by blocking the enzyme’s active site
6. A molecule that has the same shape as the substrate of an enzyme would tend to
A. * Speed metabolism by guiding the enzyme to its substrate
B. Speed metabolism because it would also be a catalyst
C. Speed metabolism by acting as a cofactor for the enzyme
D. Save the cell energy by substituting for the substrate
E. Slow metabolism by blocking the enzyme’s active site
7. A person having deficiency of lactase cannot digest
A. Proteins
B. * Milk
C. Starch
D. Fats
E. Potatos
8. A pseudo-first order reaction____________________.
A. Is a two substrate reaction whose rate depends on the concentration of both
substrates
B. * Is a single substrate reaction whose rate depends on the concentration of that
substrate
C. Is two substrate reaction whose rate depends on the concentration of only one of
the substrate
D. Is two substrate reaction whose rate is independent of either substrate
E. Is a complex substrate reaction whose rate depends on the concentration of that
substrate
9. A reaction is designated as exergonic rather than endergonic when ___________.
A. Activation energy exceeds net energy release
B. Activation energy is necessary
C. No kinetic energy is released
D. * The potential energy of the products is less than the potential energy of the
reactants
E. It absorbs more energy
10. A(n) ______ does not bind to the active site of an enzyme
A. Substrate
B. Competitive inhibitor
C. * Allosteric effector
D. A and b
E. All of the above
11. Abzymes are
A. Immuno globulins
B. Isozymes
C. * Allosteric enzymes
D. Catalytic antibodies
E. Vitamins
12. According to the second law of thermodynamics, which of the following is true?
A. The total amount of energy in the universe is constant.
B. Energy conversions increase the order in the universe.
C. * The ordering of one system depends on the disordering of another.
D. The entropy of the universe is constantly decreasing.
E. All reactions produce some heat.
13. Acyl-group-transfer reactions often involve which coenzyme?
A. * Coenzyme A
B. NAD+
C. Cytochrome c
D. All of the above
E. None of the above
14. Allosteric centers serve as:
A. * The place of influence on the enzyme different regulator factors
B. The place relation of enzyme with substrate
C. Catalytic area
D. Contact area
E. The area seperetion of the spatially united amino acid residues
15. Allosteric enzymes _____________.
A. Usually have quaternary structure.
B. Do not behave according to Michaelis-Menton kinetics.
C. * Bind allosteric modulators at sites not associated with substrate binding.
D. Often have separate catalytic and regulator domains.
E. All of the above.
16. Allosteric enzymes______________.
A. * Follow Michaelis-Menton kinetics
B. Show hyperbolic plots when plotting [S] versus Vo
C. Are monomeric proteins
D. None of the above
E. Are oligomeric proteins
17. Among the following which is the Michaelis menten equation
A. V = Km + Vmax / (S)
B. V = Vmax ( S) / ( S) + Km
C. V = V max + (S) / (S)Km
D. V = V max (S) / Km
E. * V = V max Km/S
18. Among the following, which is the wrong statement regarding to competitive inhibition
A. * The inhibitor binds to active site of an enzyme
B. There is negligible inhibition at very high substrate concentration
C. There is an increase in Km
D. The enzyme is irreversibly inhibited by inhibitor
E. The inhibitor binds to allosteric site of an enzyme
19. An allosteric activator that affects Km but not Vmax does so by_____________.
A. Altering enzyme conformation to promote substrate binding
B. Altering enzyme conformation to increase Kcat
C. * Altering enzyme conformation to prevent binding of a competitive inhibitor
D. Altering enzyme conformation to prevent E+P
E. None of the above
20. An allosteric modulator influences enzyme activity by
A. Competing for the catalytic site with the substrate
B. * Binding to a site on the enzyme molecule distinct from the catalytic site
C. Changing the nature of the product formed
D. Covalently modifying enzyme
E. All of above
21. An enzyme is a special kind of catalyst that works to
A. * Speed up a specific biochemical reaction.
B. Slow down a chemical reaction
C. Break down chemical elements.
D. Maintain the correct temperature for a reaction
E. All answers are incorrect
22. An enzyme is specific. This means
A. It has a certain amino acid sequence
B. * It is found only in a certain place
C. It functions only under certain environmental conditions
D. It speeds up a particular chemical reaction
E. It occurs in only one type of cell
23. An enzyme without its required co-factor prosthetic group is referred to as
the____________________.
A. Cenzyme
B. Apoenzyme
C. * Holoenzyme
D. Izoensymes
E. None of the above
24. An inhibitor binds to a site other than the active site of the enzyme. Which statement
below correlates with this observation?
A. It must be a competitive inhibitor.
B. The inhibition must be irreversible.
C. * It could be noncompetitive or uncompetitive inhibition.
D. It could be irreversible, competitive, noncompetitive or uncompetitive. The data
do not relate to the type of inhibition.
E. None of above
25. An ion commonly found in metalloenzymes and which can undergo reversible oxidation
and reduction is
A. Ca++
B. Mg++
C. S=
D. * Fe++
E. All of the above
26. An uncompetitive inhibitor binds to _____.
A. E
B. * ES
C. P
D. A and b
E. A and c
27. An uncompetitive inhibitor of an enzyme catalyzed reaction
A. * Binds to the Michaelis complex (ES)
B. Decreases Vmax.
C. Is without effect at saturating substrate concentration
D. Can actually increase reaction velocity in rare cases
E. The first and second choices are both correct
28. At the beginning of an enzyme-catalyzed reaction the _________ is negligible.
A. Formation of ES
B. * Formation of E + P
C. Conversion of ES to E + S
D. Disappearance of ES
E. Formation of ES*FES**
29. Avidin, a protein found in egg whites binds tightly to which cofactor?
A. Pyridoxal phosphate
B. * Biotin
C. thiamin pyrophophosphate
D. Lipoamide
E. NAD(P)H
30. Because coenzymes are specific for the chemical groups that they accept and donate, they
are referred to as
A. Cofactors
B. Reactive centers
C. Activator ions
D. * Group-transfer reagents
E. All of the above
31. Both Vmax and Km values are altered in
A. Competitive inhibition
B. Noncompetitive inhibition
C. Uncompetitive inhibition
D. * All of these
E. Reversible
32. By enzymes with relative specificity can come project:
A. * Lipasa, proteases
B. Urease
C. Arginase, sucrase
D. Suktsinatdehydrogenase
E. Alkogol dehydrogenase
33. Cleland notations are used to graphically depict _______________________.
A. Allosteric enzyme kinetics
B. The binding order of substrates and the release order of products in a
multisubstrate reaction
C. Inhibition kinetics
D. * Michaelis Menton kinetics
E. None of the above
34. Coenzymes which must return to their original form after each catalysis are called
A. Prosthetic groups
B. Cosubstrates
C. Metabolite coenzymes
D. Vitamin coenzymes
E. * All of the above
35. Cysteine and serine residues can function in ___________ when present in the active site
of an enzyme.
A. Anion binding
B. Cation binding
C. Proton transfer
D. * Acyl group binding
E. All of the above
36. During feedback inhibition, the allosteric site is often the __________ enzyme in the
pathway.
A. Last
B. Least abundant
C. Most abundant
D. * First
E. Second
37. During the procedure using the turnip extract demonstrating the affect of inhibitors, what
was the enzyme studied?
A. * Peroxidase
B. Catalase
C. Catechol oxidase
D. Hydrogen peroxide
E. Oxidoreductase
38. Enzyme cofactors that bind covalently at the active site of an enzyme are referred to as
_________.
A. Cosubstrates
B. * Prosthetic groups
C. Apoenzymes
D. Vitamins
E. Isoenzymes
39. Enzymes
A. Enhance reaction rates
B. Are affected by pH
C. Act on specific substrates
D. Are affected by temperature
E. * All of the above
40. Enzymes fast up the velocity of a biochemical reaction by
A. * Increasing activation energy
B. Decreasing kinetic energy
C. Removing the functional group
D. Decreasing activation energy
E. All of the above
41. Enzymes increase the velocity of a reaction by___________________.
A. * Increasing the ground state energy of the substrate by forming the ES complex
B. Stabilizing the formation of the transition state
C. Altering the equilibrium of the reaction
D. A and b
E. All of the above
42. Enzymes lower the activation energy for biochemical reactions. They do this by
_______.
A. * Creating energy for use in the reactions they catalyze.
B. Forming a substrate-enzyme complex
C. Releasing energy which ultimately lowers the activation energy
D. Diffusion of Na and K through the Na-K pump
E. Always having a higher energy than the substrates
43. Enzymes that are activated by proteolytic cleavage are referred to as __________.
A. Covalently modified enzymes
B. Enzyme complexes
C. * Zymogens
D. Polymerized
E. Free radicals
44. Enzymes typically have _______ affinity for the substrate than for the transition state.
A. Lower
B. * Higher
C. The same
D. None of the above
E. All of the above
45. Exactly how do inhibitors affect the reaction rate of enzymes?
A. The extra energy would cause violent movement and collisions until the bonds in
the molecule broke, causing the shape to change.
B. The high concentration of hydrogen ions (H+) would break the bonds in the
molecule, causing the shape to change.
C. The high concentration of hydroxide ions (OH-) would break the bonds in the
molecule, causing the shape to change.
D. * Because the inhibitor molecules are structurally similar to the substrate
molecules, they slow down the chemical reaction.
E. The high concentration of hydrogen peroxide (H2O2) would break the bonds in
the molecule, causing the shape to change
46. Exactly how would an extremely low pH (less than 2.0) denature an enzyme?
A. The extra energy would cause violent movement and collisions until the bonds in
the molecule broke, causing the shape to change.
B. * The high concentration of hydrogen ions (H+) would break the bonds in the
molecule, causing the shape to change.
C. The high concentration of hydroxide ions (OH-) would break the bonds in the
molecule, causing the shape to change.
D. Because pH molecules are structurally similar to the substrate molecules, they
inhibit the chemical reaction.
E. All of above
47. Glucose + ATP > Glucose -6-phosphate + ADP. This reaction is catalysed by which of
the following enzyme classes
A. Oxidoreductase
B. * Transferase
C. Hydrolase
D. Lyase
E. Isomerases
48. Heterolytic carbon-carbon bond cleavage can result in the formation of_____.
A. Carbocation
B. * Radical species
C. Carbanion
D. A and b
E. A and c
49. How many active centers can have enzymes?
A. 1
B. 3
C. 2
D. * Depends on the amount of subunits of enzyme
E. 10
50. If a protein is reversibly denatured, which structural level can you be sure has remained
intact?
A. * Primary only
B. Secondary only
C. Tertiary only
D. Quaternary only
E. How sure do I have to be -?
51. If the absolute concentration of enzyme is unknown, which of the following values can
not be determined experimentally?
A. Km
B. kcat
C. * Vmax
D. None of the above
E. All of the above
52. If the substrate concentration in an enzyme catalyzed reaction is equal to 0.5 Km, the
initial reaction velocity will be
A. 0.25 Vmax
B. 0.33 Vmax
C. 0.50 Vmax
D. * 0.75 Vmax
E. 0. 15 Vmax
53. If the tertiary structure of an enzyme is changed _____.
A. Its substrate may not fit properly in the active site
B. It will be missing one of its polypeptides
C. * The helical coil will be stretched out
D. The product of the reaction will be a different molecule
E. Its substrate will bond covalently with the wrong part of the molecule
54. In a first order chemical reaction, the velocity of the reaction is proportionate to the
_____, while in a zero order reaction, the velocity of the reaction is proportionate to
_____.
A. Amount of enzyme; concentration of substrate
B. * Concentration of substrate; amount of enzyme
C. Concentration of substrate; the speed of the reaction
D. The speed of the reaction; concentration of substrate
E. All of the above
55. In an enzyme reaction involving one enzyme and one substrate, the rate of the reaction
depends on
A. Substrate concentration
B. Enzyme concentration
C. * Both substrate and enzyme concentrations
D. The enzyme concentration at first and the substrate concentration later on
E. Speed of reaction
56. In describing enzyme feature, enzymes:
A. Are composed primarily of polypeptides, which are polymers of amino acids
B. Can bind prosthetic groups such as metal ions that participate in enzyme reactions
C. Have defined structures.
D. * Bind their substrates at active sites
E. All statements are true
57. In describing the reaction rate for a chemical reaction, which of the following statements
about reaction rate is NOT true?
A. Reaction rate is the speed at which the reaction proceeds toward equilibrium.
B. * Reaction rate is governed by the energy barrier between reactions and products
C. Enzymes can accelerate the rate of a reaction
D. Reaction rates are not sensitive to temperature.
E. None of these
58. In formation of temporal complex between an enzyme and substrate important role
belongs chemical bonds, except:
A. Disulfide
B. Ion
C. * Peptid
D. Hydrogen bonds
E. Hydrophobic interaction
59. In understanding activation energy, activation energy is
A. * Energy that must be added to get a reaction started, which is recovered as the
reaction proceeds
B. Difference in energy between reactants and products
C. Energy that is lost as heat.
D. Free energy
E. Equal to the entropy times the absolute temperature
60. In which of the following do both examples illustrate kinetic energy?
A. * Positions of electrons in an atoma ball rolling down hill
B. Heatarrangement of atoms in a molecule
C. A rock resting on the edge of a cliffheat
D. A ball rolling down a hillheat
E. Lightarrangement of atoms in a molecule
61. In which of the following do both examples illustrate kinetic energy?
A. Positions of electrons in an atoma ball rolling down hill
B. Heatarrangement of atoms in a molecule
C. * A rock resting on the edge of a cliffheat
D. A ball rolling down a hillheat
E. Lightarrangement of atoms in a molecule
62. is known as _________ inhibition.
A. * Competitive
B. Uncompetitive
C. Uncompetitive
D. Feedback
E. Allosteric
63. Isoenzymes are generally separated by
A. Ion exchange chromatography
B. Gel filtration chromatography
C. Paper chromatography
D. * Electrophoresis
E. Selective adsorbtion
64. Km is _______.
A. The substrate concentration at ? Vmax.
B. = (k-1 + kcat)/k1
C. Related to an enzymes affinity for a specific substrate.
D. * The Michaelis Constant
E. All of the above
65. Km values are not altered by which type of inhibitor
A. * Competitive inhibitors
B. Non competitive inhibitors
C. Uncompetitive inhibitors
D. Allosteric inhibitor
E. All of these
66. Lactate dehydrogenase is a
A. Coenzyme
B. * Isoenzyme
C. Zymogen
D. Abzyme
E. Prostetic group
67. Michaelis constant Km is
A. Dependent on enzyme concentration
B. Independent of Ph
C. * Equal to substrate concentration that gives half Vmax
D. Numerically equal to half Vmax
E. Dependent on substrate concentration
68. Minerals and metals are often used in or as
A. Enzymes and coenzymes
B. * Coenzymes and cofactors
C. Cofactors and prosthetic groups
D. Coenzymes and prosthetic group
E. Prizes in the subcellular Olympics
69. Molybdenum is present in
A. Carboxypeptidase
B. Dinitrogenase
C. Pyruvate dehydrogenase
D. Pyruvate carboxylases
E. * Xantinoxidase
70. Most enzymes are composed of.
A. Lipids
B. Carbohydrates
C. * Proteins
D. Phosphates
E. Vitamins
71. Most enzymes are composed of.
A. Lipids
B. Carbohydrates
C. * Proteins
D. Phosphates
E. Vitamins
72. Name of enzyme which include zinc?
A. * Alkohol dehydrogenase
B. Cytochromoxidase
C. Xantinoksidase
D. Pyruvate dehydrogenase
E. Lactate dehydrogenase
73. Nicotinamide is ____________.
A. A co-substrate
B. A metabolite coenzyme
C. * A vitamin
D. A prosthetic group
E. None of the above
74. Noncompetitive inhibitor binds with
A. Active site
B. Allosteric site
C. Enzyme substrate complex
D. * Substrate
E. Product of reaction
75. Pyridoxal phosphate is involved in which type of reaction?
A. Oxidation of pyruvate
B. * Production of new amino acids by transamination
C. Phosphate-transfer to produce ATP from ADP
D. The regeneration of methionine from homocysteine
E. None of the above
76. Reaction order describes which of the following.
A. The order that substrates bind to the enzyme.
B. The order of reactions in a biosynthetic pathway
C. * How the velocity of a reaction is dependent on the concentration of specific
reactants.
D. All of the above
E. A and c
77. Role of coenzymes can active part vitaminesimillar substens. What matters does not act
part as coenzyme:
A. Ubiquinone
B. Lipoic acid
C. Carnitin
D. * Orotic acid
E. Pangamic acid
78. Some enzymes involved in the hydrolysis of ATP cannot function without help of sodium
ions. Sodium in this case functions as
A. A substrate
B. * A cofactor
C. An active site
D. A noncompetitive inhibitor
E. A vitamin
79. Some enzymes involved in the hydrolysis of ATP cannot function without help of sodium
ions. Sodium in this case functions as
A. A substrate
B. * A cofactor
C. An active site
D. A noncompetitive inhibitor
E. A vitamin
80. Substrate binding site on the enzyme is
A. * Active site
B. Allosteric site
C. Prostetic group
D. Cofactor
E. All of above
81. Temperature optimum of enzymes - is:
A. * Temperature which speed of enzymatic reaction is maximal
B. Temperature which is denaturation of enzymes
C. A size speed of reaction is at the temperature of 48-560С
D. The best conditions of bringing together are between an enzyme and substrate
E. Temperature which metabolic processes are inhibits
82. The active site of an enzyme
A. Remains rigid and does not change shape
B. Is found at the center of globular enzymes
C. Is complementary to the rest of the molecule
D. * Contains amino acids without sidechains
E. None of the above choices are correct
83. The activity of a zymogen is activated by____________.
A. Covalent modifications
B. Allosteric regulation
C. Association/disassociation of subunits
D. * Proteolytic modification
E. None of the above
84. The amino acid ________ can function in proton transfer when present in the enzyme
active site.
A. Glutamate
B. Aspartate
C. * Histidine
D. Lysine
E. All of the above
85. The apparent Km of an enzyme changes when the enzyme is treated with a_____.
A. Competitive inhibitor.
B. * Uncompetitive inhibitor.
C. Noncompetitive inhibitor
D. A and b.
E. B and c.
86. The coenzyme biotin is involved in the transferring of the following groups
A. Amino group
B. * CO2
C. One carbon group
D. Acyl group
E. Amino acid residues
87. The coenzyme present in isocitrate dehydrogenase
A. * NAD+
B. NADP+
C. FAD
D. TPP
E. Biotin
88. The coenzyme present in transaminase
A. NAD+
B. TPP
C. Coenzyme A
D. * Pyridoxal phosphate
E. Biotin
89. The enzyme Creatine kinase levels are increased in the blood of patients with
A. Prostate cancer
B. * Hepatitis
C. Heart attack
D. Osteoporosis
E. Muscle atonia
90. The enzyme involved in bone formation
A. * Acid phosphatase
B. Urease
C. Alkaline phosphatase
D. Calcitonin
E. Catalase
91. The enzyme kinase requires
A. * Mg
B. Mn
C. K
D. Mo
E. Сu
92. The enzyme which transfer groups between atoms within a molecule are
A. Recemases
B. Mutases
C. * Transferases
D. Oxido-reductases
E. All of these
93. The enzymes are inherent all physical and chemical properties of proteins, except:
A. High molecular mass
B. Breaking up to amino acid during a hydrolysis
C. Formation of colloid solutions
D. Antigen properties
E. * Stable is to influence of high temperatures and salts of heavy metals
94. The equilibrium constant for the conversion of the disaccharide sucrose to the simple
sugars glucose and fructose is 140,000. What can you conclude about the reaction:
sucrose + H2Ooglucose + fructose?
A. It is a closed system
B. It never reaches equilibrium
C. It is spontaneous, starting with sucrose
D. The equilibrium constant increases when the starting concentration of sucrose is
increased
E. * At equilibrium, the concentration of sucrose is much higher than the
concentrations of glucose and fructose.
95. The equilibrium constant for the ionization of acetic acid, is 0.00002. What can you
conclude about this reaction?
A. It is a closed system
B. * At equilibrium, the concentration of CH3COOH is much higher than the
concentrations of CH3COO- + H+.
C. It never reaches equilibrium.
D. It is spontaneous, starting with CH3COOH.
E. The equilibrium constant increases when the starting concentration of CH3COOH
is increased
96. The hydrophobic cleft in globular proteins which bind substrate molecules is called
A. The substrate pocket
B. The modulator site
C. The active site
D. The activity site
E. * The oligomeric site
97. The inactive precursor of an active enzyme is called
A. Zymogen
B. Ribozyme
C. Isozyme
D. * Abzyme
E. Nucleozyme
98. The inhibition of succinate dehydrogenase by malonate is an example for
A. * Competitive inhibition
B. Non competitive inhibition
C. Uncompetitive inhibition
D. Feedback or end product inhibition
E. None of these
99. The initial velocity assumption for Michaelis-Menton kinetic assumes that ______.
A. * The reaction is always running at Vmax.
B. The rate of E + P -> ES is negligible.
C. A large amount of product has formed.
D. K-2 is large.
E. None of the above.
100.
The initial velocity assumption of the Michaelis-Menton equation states that
__________.
A. * The rate of ES formation is equal to the rate of ES turnover
B. A large amount of product is formed
C. The rate of the P T ES reaction is negligible
D. a and b
E. b and c
101.
The ions of what metal contain porphirine coenzymes?
A. Na
B. * Fe
C. Zn
D. Mo
E. Mn
102.
The low value of Km indicates
A. High enzyme activity
B. High substrate affinity of enzyme
C. No effect on reaction
D. * Low affinity of enzyme with substrate
E. All of these
103.
The mechanism of enzyme action is _____.
A. To create an energy barrier between substrates
B. To lower the energy of the activation of a reaction
C. * To change the direction of thermodynamic equilibrium
D. To change endergonic into exergonic reactions
E. To allow substrates to move more freely in solution
104.
The non protein compound that acts as enzyme is
A. * DNA
B. RNA
C. Carbohydrate
D. Fat
E. Vitamins
105.
The noncompetitive inhibitor
A. Increases Vmax and Km
B. * Decreases Vmax
C. Increases Km without affecting Vmax
D. Decreases Km and Vmax
E. Increases Km
106.
The product(s) of lactate dehydrogenase under anaerobic conditions is (are)
A. Pyruvic acid
B. NAD+
C. NADH
D. A and b
E. * A and c
107.
The relationship between an enzyme and a reactant molecule can best be
described as:
A. A temporary association
B. An association stabilized by a covalent bond
C. * One in which the enzyme is changed permanently
D. A permanent mutual alteration of structure
E. Noncomplementary binding
108.
The role of zinc in the mechanisms of carbonic anhydrase is to
A. Maintain the configuration of the holoenzyme
B. Bind to three histidine residues
C. Produce a nucleophilic attack on the substrate
D. * Promote ionization of bound water
E. Produce an electrophilic attack on the substrate
109.
The rules are for each half-reaction:
A. Balance all elements except hydrogen and oxygen.
B. Balance oxygen by adding water (H2O(l)).
C. Balance hydrogen by adding H+(aq) ion
D. * Balance charge by adding electrons
E. Increase speed of reaction
110.
The specific activity of an enzyme is
A. The amount of enzyme that produces one mole of product per second under
standard conditions
B. The activity of an enzyme in relation to a standard preparation of the enzyme
C. The number of enzyme units per milligram of enzyme protein
D. * The activity of an enzyme in the presence of its preferred substrate
E. All of above
111.
The term given to the number of substrate molecules an enzyme can process per
second –
A. Reaction rate
B. * Michaelis constant
C. Optimal rate
D. Turnover rate
E. The substrate processing number
112.
The transition state of a catalyzed reaction (EX‡) is
A. * A highly-populated intermediate on the reaction pathway
B. Higher in energy than that of an uncatalyzed reaction
C. Lower in energy than that of an uncatalyzed reaction
D. Lower in energy than the reaction substrate
E. Bound very weakly to the catalyst
113.
The typical saturation curve for an enzyme catalyzed reaction is sigmoidal. This
indicates that the enzyme is
A. * A regulatory enzyme
B. A nonregularoty enzyme
C. Both
D. None
E. All of above
114.
The uncompetitive inhibitor binds with
A. Active site
B. Allosteric site
C. * Enzyme substrate complex
D. Substrate
E. Product of reaction
115.
Trypsin is a
A. * Exopeptidase
B. Endopeptidases
C. Carboxy peptidase
D. Phosphotransferase
E. Phosphopeptidase
116.
Unlike typical catalyzed reactions in organic chemistry enzyme reactions are
A. Usually stereospecific
B. Reaction specific
C. Essentially 100% efficient
D. Modulated to change activity levels.
E. * All of the above.
117.
Vmax ______________________.
A. Describes the velocity of reaction when substrate is bound to ? of the available
substrate binding sites on an enzyme
B. * Describes the velocity of reaction when all of the available substrate binding
sites on an enzyme are occupied by substrate
C. Is a rate constant for the reaction where the ES complex is converted to the E +
D. Is the value equal to one over the x intercept of a Lineweaver Burk plot.
E. B and d
118.
What component is not included in the structure of holoenzymes?
A. Apoenzyme
B. Coenzyme
C. Cofactor
D. Prostetic group
E. * Izoenzyme
119.
What distinguishes reversible inhibitors from irreversible inhibitors?
A. Reversible inhibitors are not covalently bound to enzymes but irreversible
inhibitors are.
B. There is an equilibrium between bound and unbound reversible inhibitor. There
usually is little back reaction for the binding of an irreversible inhibitor.
C. Reversible inhibitors are easier to purify from solutions of enzymes than
irreversible inhibitors.
D. * All of the above.
E. a and b only.
120.
What does appear common for enzymes with relative specificity?
A. * Action on the identical type of bonds of certain group of substrates
B. Ability to convert one substrate
C. Ability to influence on D - isomers
D. Influence on D- isomers, but does not influence on L- isomers
E. Action on a few types of bonds of certain group of substrates
121.
What feature is not commonly for all izoenzymes?
A. Action on the one substrate
B. Catalysis of identical reactions
C. Finding in different tissuers
D. * Electrophoretic mobility
E. Izoenzymes is typical for most enzymes, that in the structure have a few subunits
122.
What is the area of an enzyme called where the chemical reactions occur?
A. The Cytoplasm
B. * The Active Site
C. The Catalyst
D. The Nucleus
E. A substrate
123.
What method was the presence in the first time set by izoenzymes?
A. Dialysis
B. * Elektroforezis in the starched gael
C. Chromatography
D. Centrifugation
E. Rengen analysis
124.
What structure of proteins molecule is responsible for formation of active centre
and for his catalytic action?
A. Primary
B. * Tertiary
C. Secondary
D. Quaternary
E. None from following
125.
When considering the features of an exergonic reaction, exergonic reactions:
A. * Release energy
B. Are spontaneous reactions
C. Have an equilibrium constant greater than 1
D. Can be coupled to energonic reactions
E. All statements are true.
126.
When you plot [S] versus initial velocity for an allosteric enzyme, what type of
plot arises?
A. * Hyperbolic
B. Sigmoidal
C. Linear
D. Discontinuous
E. Exponential
127.
Which aminoacids residues does not enter in the composition of active center of
enzyme?
A. Serine
B. Cystein
C. Histidin
D. Thyrosin
E. * Arginine
128.
Which coenzyme is covalently bound to the enzyme active site?
A. NAD+/NADH
B. * Lipoamide
C. Coenzyme A
D. None of the above
E. Biotin
129.
Which coenzyme is likely involved in the reaction shown below?
A. * TPP
B. Biotin
C. Coenzyme A
D. FMN
E. NAD
130.
Which coenzyme links to a lysine residue in a protein's active site?
A. Biotin
B. Lipoic acid (lipoamide)
C. Pyridoxal phosphate
D. Biotin and pyridoxal phosphate only
E. * All three; biotin, lipoic acid and pyridoxal phosphate
131.
Which commonly involve some sort of mineral or metal?
A. Ligands and binding sites
B. Cofactors and prosthetic groups
C. * Coenzymes and cofactors
D. Ligands and prosthetic groups
E. Nasty scraping sounds
132.
Which enzymes do not enter in the complement of porphirine coenzymes?
A. Cytochrome b, с
B. Catalase
C. Peroxidase
D. * Phosphatase
E. Cytochrome а1, а
133.
Which of the following best describes the ability of an enzyme to convert the ES
complex to E + P?
A. * Vmax
B. Km
C. Kcat
D. Kcat/Km
E. All of the above
134.
Which of the following coenzymes functions in acyl transfer reactions?
A. NADPH
B. * Coenzyme A
C. Biotin
D. A and b
E. B and c
135.
Which of the following coenzymes participates in enzymatic mechanisms by
producing a free radical intermediate?
A. NADPH
B. Ubiquinone
C. Methylcobalamin
D. Biotin
E. * Lipoamide
136.
Which of the following is a property of a catalyst?
A. A catalyst can alter the equilibrium of a chemical reaction.
B. A catalyst is changed to a different form at the end of a reaction.
C. * A catalyst can increase the rate of a chemical reaction.
D. a and c
E. all of the above
137.
Which of the following is best used to determine how well a specific substrate is
used by a specific enzyme?
A. Km
B. * kcat
C. Vmax
D. kcat/ Km
E. ? Vmax
138.
Which of the following is true of enzymes that are regulated by allosteric
regulation?
A. * They are usually multimeric enzymes
B. A hyperobolic curve results from the plotting of Vo vs [S]
C. They behave according to Michaelis-Menton kinetics
D. A and b
E. B and c
139.
Which of the following kinetic parameters best describes the ability of a specific
substrate to bind to a specific enzyme?
A. Vmax
B. Km
C. Kcat
D. Kcat/Km
E. * All of the above
140.
Which of the following statements is FALSE?
A. Enzymes make reactions 103 to 1017 times faster.
B. Enzymes lower the amount of energy needed for a reaction.
C. * Enzymes are unchanged during a reaction.
D. Enzymes speed up the attainment of a reaction equilibrium.
E. Enzymes are proteins.
141.
Which of the following types of reactions will result in a hyperbolic plot when [S]
is plotted versus initial velocity?
A. Allosterically regulated reactions
B. Multi-step reactions
C. * Michaelis Menton reactions
D. A and c
E. All of the above
142.
?Which of the statements regarding enzymes is false?
A. Enzymes are proteins that function as catalysts
B. Enzymes are specific
C. * Enzymes provide activation energy for reactions
D. Enzyme activity can be regulated
E. Enzymes may be used many times for a specific reaction
143.
Which of these phrases best describes how enzymes affect chemical reactions?
A. Lower the activation energy
B. Raise the activation energy
C. * Supply activation energy
D. Remove activation energy
E. Could it have something to do with activation energy.?
144.
Which of these statements about enzyme inhibitors is true?
A. * A competitive inhibitor binds to the enzyme outside the active site.
B. The action of competitive inhibitors may be reversible or irreversible.
C. A noncompetitive inhibitor does not change the shape of the active site.
D. When the product of an enzyme or an enzyme sequence acts as its inhibitor, this
is known as positive feedback
145.
146.
147.
148.
149.
150.
151.
152.
E. Antibiotics and pesticides generally do not act on enzymes, but rather affect the
genetic code of their victims
Which of these statements about enzyme inhibitors is true?
A. * A competitive inhibitor binds to the enzyme outside the active site
B. The action of competitive inhibitors may be reversible or irreversible
C. A noncompetitive inhibitor does not change the shape of the active site
D. When the product of an enzyme or an enzyme sequence acts as its inhibitor, this
is known as positive feedback.
E. Antibiotics and pesticides generally do not act on enzymes, but rather affect the
genetic code of their victims.
Which one of the following is an example of the second law of thermodynamics?
A. The aerobic respiration of glucose generates heat.
B. * All types of cellular respiration produce ATP.
C. CO2 is exhaled as a by-product of aerobic respiration.
D. Photosynthesis enables plants to create energy from sunlight.
E. Energy is stored during the Calvin cycle.
Which statement about enzyme catalyzed reactions is NOT true?
A. Enzymes form complexes with their substrates
B. Eenzymes lower the activation energy for chemical reactions.
C. Eenzymes change the Keq for chemical reactions.
D. * Many enzymes change shape slightly when substrate binds.
E. Reactions occur at the "active site" of enzymes, where a precise 3D orientation of
amino acids is an important feature of catalysis
Which statement about enzyme catalyzed reactions is NOT true?
A. Enzymes form complexes with their substrates
B. Enzymes lower the activation energy for chemical reactions
C. Enzymes change the K eq for chemical reactions
D. Many enzymes change shapes slightly when substrate binds
E. * Reactions occur at the "active site" of enzymes, where a precise 3D orientation
of amino acids is an important feature of catalysis
Which statement regarding enzyme function is true?
A. * Higher temperatures allow greater contact between enzymes and substrates;
therefore, the higher the temperature the better the enzyme will function.
B. Enzymes cannot function at a pH lower than 6.
C. Most coenzymes are inorganic substances such as ions of iron or potassium.
D. Excessive salt ions can cause an enzyme to denature.
E. All of the above.
Which statement regarding enzyme function is true?
A. Higher temperatures allow greater contact between enzymes and substrates;
therefore, the higher the temperature the better the enzyme will function.
B. Enzymes cannot function at a pH lower than 6.
C. Most coenzymes are inorganic substances such as ions of iron or potassium.
D. Excessive salt ions can cause an enzyme to denature.
E. * All of the above.
Which type of regulation occurs in the slowest time frame?
A. Regulation through covalent modification
B. Allosteric regulation
C. New synthesis of enzyme through gene induction
D. * Feedback regulation
E. None of the above
Which type of specificity of enzymes does not existence?
A. Relative
B.
C.
D.
E.
Absolute
* Conformation
Space specificity
Stereospecificity
153.
Which vitamins does not appear as coenzymes?
A. B1
B. B2
C. B5
D. * С
E. B12
154.
Which would most likely not have much stereospecificity?
A. * Antibodies
B. Receptors
C. Enzymes
D. Codons
E. People who buy their components at Wal-Mart
155.
Why does heating interfere with the activity of an enzyme?
A. It kills the enzyme
B. It changes the enzyme’s shape
C. It decreases the energy of substrate molecules
D. * It causes the enzyme to break up
E. It decreases the chance that the enzyme will meet a substrate molecule
156.
Zinc is present in which of the following enzymes
A. Cytochrome oxidase
B. Arginase
C. Hexokinase
D. * Alcoholdehydrogenase
E. Catalase
157.
A 37 years old man was delivered to the hospital with symptoms of sharp
pancreatitis: vomiting, diarrhea, bradicardia, hypotension, weakness, dehydration of
organism. What preparation should be used for the treatment?
A. Ephedrine
B. * Kontrikal
C. Platifilin
D. No-spa
E. Etaperazin
158.
A 45 years old patient suffers from pain in lumbar department of the back and its
limited mobility. It is takes place darkening of urine with air. What inherited disease has
the patient?
A. Phenylketonuria
B. Galactosemia
C. * Alkaptonuria
D. Cystinosis
E. Syndrome of Fankoni
159.
A 45 years old patient suffers from pain in lumbar department of the back and its
limited mobility. It is takes place darkening of urine with air. What inherited disease has
the patient?
A. Phenylketonuria
B. Galactosemia
C. * Alkaptonuria
D. Cystinosis
E. Syndrome of Fankoni
160.
A 46 years old woman appealed to the doctor with complaints about pain in the
epigastrium after the fatty meal. Doctor suspected acute pancreatitis. Content of which
from the transferred substances in blood increased at this pathology?
A. Glucose
B. Aspartate amino transferase
C. Alanine amino transferase
D. * Amylase
E. Calcium
161.
A 47-years-old man was delivered to the hospital with the diagnosis –
myocardium infarction. What factions of LDH will prevail in the blood serum during the
first two days of disease?
A. LDH3
B. LDH2
C. * LDH1
D. LDH4
E. LDH5
162.
A 60-years-old man appealed to the doctor with complains of pain in a thorax. In
the blood serum were established increase of such enzymes activity: MB isoforms of
creatin phospho kinase, aspartate amino transpherase. About development of pathological
process in what organ or tissue do these changes testify?
A. In lungs
B. * In cardiac muscle
C. In skeletal muscles
D. In the liver
E. In smooth muscles
163.
A blood test was done in a biochemical laboratory with the diagnostic purpose for
a patient with the early stage of muscular dystrophy. Increase of activity of what enzyme
can be observed in this case?
A. Alanine aminotransferase
B. * Creatin kinase
C. Collagenase
D. Hyaluronidase
E. Glutaminase
164.
A child was delivered to a reanimation with such symptoms: vomit, diarrhea,
abnormal physical and mental development, cataract. Laboratory test showed
galactosemia. The deficiency of what enzyme does take place?
A. Galactokinase
B. UDP glucose-4-epimerase
C. * Hexose-1-phosphate-uridiltransferase
D. UDP- glucose –pyrophosphorilase
E. Glucose-6-phosphate dehydrogenase.
165.
A new-born child has diarrhea, vomiting and cataract. Disorder of synthesis of
what enzyme causes this disease?
A. * Galactose – 1 – phosphate uridyl transpherase
B. Glucose - 6 phosphatase
C. Hexokinase
D. Glycogen synthase
E. Glucose phosphate isomerase
166.
A new-born child has diarrhea, vomiting and cataract. Disorder of synthesis of
what enzyme caused this disease?
A. * Galactose – 1 – phosphate uridyl transpherase
B. Glucose - 6 phosphatase
C. Hexokinase
D. Glycogen synthase
E. Glucose phosphate isomerase
167.
A newborn suffers from the fatty degeneration of liver, takes place a galactosuria
and amino aciduria, increased level of total bilirubin in blood. What matter is it necessary
to exclude from the diet of child?
A. * Lactose
B. Fatty acids
C. Phenylalanine
D. Cholesterol
E. Saccharose
168.
A patient complains about acute stomach-ache, nausea, vomitting. Diastase
activity is 800 grammes/l hour What diagnosis is the most possible?
A. Acute cholecystitis
B. * Acute pancreatitis
C. Ulcer of stomach
D. Acute appendicitis
E. Enterocolitis
169.
A patient complains about acute stomach-ache, nausea, vomit. Diastase activity is
800 grammes/l•hour What diagnosis is the most possible?
A. Acute cholecystitis
B. * Acute pancreatitis
C. Ulcer of stomach
D. Acute appendicitis
E. Enterocolitis
170.
A patient complains about pain on the left side in breast, weakness and
tachycardia. What from the transferred enzymes is it necessary to define in blood for
confirmation of diagnosis of heart attack of myocardium?
A. * AsAT, CPK MB, LDH-1
B. AlAT, aldolase, LDH-4
C. Amylase, alkaline фосфатаза, ALAT
D. Acidic phosphatase, LDH-5, LDH-4
E. fetoprotein, aldolase, CK
171.
A patient has disorder of liver functions. Which from the below mentioned
biochemical indexes in blood is used for the estimation of the liver state?
A. * AlAT
B. LDH1
C. Creatin phosphokinase
D. Aldolase
E. Lipase
172.
A patient has metabolic acidosis. How will it change activity of intracellular
enzymes?
A. Activity of intracellular enzymes do not change substantially.
B. Activity of mitochondrial enzymes increased, activity of lysosomal enzymes
inhibited, which is accompanied the decline of catalytic processes
C. * Activity of mitochondrial enzymes is low, activity of lysosomal enzymes, which
will result in strengthening of catalytic processes, is increased
D. Total inhibition of all of tissue enzymes
E. Total activating of all of tissue enzymes
173.
A patient has metabolic acidosis. How will it change activity of intracellular
enzymes?
A. Activity of intracellular enzymes does not change substantially
B. Activity of mitochondrial enzymes increases, activity of lysosomal enzymes
inhibits, which is accompanied the decline of catalytic processes
C. * Activity of mitochondrial enzymes is low, activity of lysosomal enzymes, which
will result in strengthening of catalytic processes, is increased
D. Total inhibition of all of tissue enzymes
E. Total activating of all of tissue enzymes
174.
A patient is found to be deficient in the enzyme galactose 1-phosphate
uridylyltransferase. Specifically due to this deficiency what might a doctor recommend?
A. avoid all strenuous exercise
B. eat a fat-free diet
C. increase intake of vitamin C
D. * avoid ingestion of milk and milk products
E. all of the above.
175.
A patient was delivered to a hospital. Possible diagnosis - acute pancreatitis. The
increase of activity of what enzyme can prove this disease?
A. Creatin kinase
B. Pepsin
C. Gastrixin
D. * Amylase
E. Aspartate transaminase
176.
A specific test on the damage of kidneys tissues for the proof of diagnosis inflammatory process in kidneys of the patient was conducted. This test is determination
in urine:
A. Concentrations of creatin
B. Activity of creatin phosphokinase MB
C. Presence of lactose
D. * Activity of transamidinase
E. Activity of pepsin
177.
A two years old child was delivered to the hospital with symptoms of mental and
physical underdevelopment, which suffers from the frequent vomiting after meal. In urine
found out phenyl-pyruvic acid. Disorder of which substances metabolism is this
pathology?
A. Phosphorus-calcium metabolism
B. Water-salt metabolism
C. * Metabolism of amino acids
D. Carbohydrates metabolism
E. Lipids metabolism
178.
A two years old child was delivered to the hospital with symptoms of mental and
physical underdevelopment, which suffers from the frequent vomiting after meal. In urine
found out phenyl-pyruvic acid. Disorder of which substances metabolism is this
pathology?
A. Phosphorus-calcium metabolism
B. Water-salt metabolism
C. * Metabolism of amino acids
D. Carbohydrates metabolism
E. Lipids metabolism
179.
Acute pancreatitis of the patient was diagnosed. Determination of which from the
below mentioned enzymes in blood can be a diagnostic criteria?
A. LDH
B. Aldolase
C. * Amylases
D. Creatin kinase
E. Alanine amino peptidase
180.
Acute pancreatitis was diagnosed after biochemical analyses. In order to avoid
autolysis of pancreas it is necessary to apply such preparations:
A. Complex of pancreatic enzymes
B. Insulin
C. * Inhibitors of proteolytic enzymes
D. Antibiotics
E. Sulfanilamides
181.
An acute pancreatitis and parotitis are diagnosed. How will it influence on the
activity of amylase in urine?
A. * High activity of amylase is in urine.
B. Low activity of amylase is in urine.
C. No any of amylase in urine.
D. No any changes.
E. All answers are correct.
182.
An acute pancreatitis and parotitis are diagnosed. How will it influence on the
activity of amylase in urine?
A. * High activity of amylase is in urine
B. Low activity of amylase is in urine
C. No any of amylase in urine
D. No any changes
E. All answers are correct.
183.
At an inspection In blood of the patient was found increase of enzymes activity:
creatin kinase, AsAT and LDH1, 2. What diagnosis is it possible in this case?
A. Muscular dystrophy
B. * Infarction of myocardium
C. Cirrhosis of liver
D. Disorders of CNS
E. Pancreatitis
184.
At the inspection of patient was diagnosed alkaptonuria. The deficiency of what
enzyme causes this pathology?
A. * Oxidase of homogentisic acid
B. Phenylalanine hydroxylase
C. Thyrosinase
D. Thyroxin hydroxylase
E. Mono amino oxidase
185.
At the inspection of patient was diagnosed alkaptonuria. The deficiency of what
enzyme causes this pathology?
A. * Oxidase of homogentisic acid
B. Phenylalanine hydroxylase
C. Thyrosinase
D. Thyroxin hydroxylase
E. Mono amino oxidase
186.
At the inspection of patient was found an increase of LDH activity in blood. It is
possible at the diseases of heart, liver, kidneys. What additional biochemical test should
be done for proper diagnostics?
A. Determination of sugar is in blood
B. * Determination of isoforms of LDH
C. Determination of ketone bodies level in blood
D. Determination of cholesterol level in blood
E. Determination of amylase in blood
187.
At treatment of bleeding wounds with a 3% hydrogen peroxide there forms a foam
due to decomposition of hydrogen peroxide with enzyme of blood. Choose this enzyme:
A. Monoaminooxidase
B. Carboanhydrase
C. Cytochromoxidase
D. * Catalase
E. Lactate dehydrogenase
188.
At treatment of bleeding wounds with a 3% hydrogen peroxide there forms a foam
due to decomposition of hydrogen peroxide with enzyme of blood. Choose this enzyme:
A. Monoaminooxidase
B. Carboanhydrase
C. Cytochromoxidase
D. * Catalase
E. Lactate dehydrogenase
189.
Cardiac muscle contains which of the following CK isoenzyme?
A. BB only
B. MM and BB only
C. MM, BB and MB
D. * MM and MB only
E. None of the above
190.
Diastase can be used for the hydrolysis can be used for the hydrolysis of
A. Sucrose
B. * Starch
C. Cellulose
D. Maltose
E. None of the above
191.
Enzymes of amnion liquid of 28 years old pregnant women weredetermined.
Insufficient activity of glucuronidase was detected. What pathological process is
possible?
A. Glycogenosis
B. * Mucopolysacharidosis
C. Aglycogenosis
D. Collagenosis
E. Lipidosis
192.
estimation will have the best predictive value?
A. Serum AST
B. Serum CK
C. Serum ALT
D. * Serum LDH
E. All of the above
193.
Festering wound was washed a with a hydrogen peroxide, but foam did not
appear. The possible reason of it is:
A. * Inherent absence of catalase
B. Too match of the rot in a wound
C. Small wound
D. A lack of iron in an organism
E. Lack of peroxydase
194.
For 18 years old patient with acute toxic hepatitis in the blood serum will be
enhanceable level:
A. * Alaninaminotransferase
B. Creatinkinase
C. Alkaline phosphatase
D. D-amilase
E. Lactate dehydrogenase-1 (LDH1)
195.
For a child which borned 2 days ago, observe the yellowing colour of skin and
mucus shells. Reason of such state can be a lack of enzyme:
A. * UDP-glyucuroniltransferase
B. Sulphontransferase
C. Hemshyntetase
D. Hemoxigenase
E. Biliverdinreductase
196.
For cleaning of festering wound and their rapid healing used immobilized trypsin
on bandaging material. What it advantage as for the native enzyme?
A. * Long term of action
B. Higher activity
C. Higher specificity of action
D. Higher sensitivity to the temperature
E. Higher sensitivity to the changes of рН
197.
For cleaning of festering wound pharmaceutical enzymes preparations are used.
Specify what matter will be effective for cleaning from necrotizing tissues and wounds
healing :
A. Washing with glucose oxidase
B. * Applications with Trypsin
C. Washing with a hydrogen peroxide
D. Imposition of sterile bandages
E. Imposition of bandages with NaCl
198.
For diagnostic of acute inflammatory process in kidneys was conducted a specific
test - determination in urine of such substance:
A. Content of lactose
B. Activity of creatinkinase
C. Concentrations of creatin
D. Activity of pepsin
E. * Activity of alanine amino peptidase
199.
For dissolving of scars, compressions, hematomas, the easier transport of
medications in tissues such enzyme is used:
A. Trypsin
B. Ribonuclease
C. * Hyaluronidase
D. Plasmin
E. Pepsin
200.
For the patient with respiratory infection sulphanylamide preparation
(sulphodimetoxin) was recommended. What mechanism of action of this preparation:
A. * Competitive inhibition of enzymes of folic acid formation from Para-amino
benzoic acid of microorganisms
B. Inhibition of translation of bacterial proteins.
C. Noncompetitive inhibition of viral cytochrome oxydase.
D. Inhibition of transcription initiation
E. Irreversible inhibition of viruses replication.
201.
For treatment of dermatitises, wounds and ulcers which heal badly are used
coenzyme preparations of flavin mononucleotide and flavinate. The active forms of
which vitamin are they?
A. B1
B. * B2
C. B5
D. B3
E. C
202.
For treatment of dermatitises, wounds and ulcers which heal badly used
coenzymes preparations of flavin mononucleotide and flavinate. The active forms of
what vitamin are they?
A. * B2
B. B1
C. B5
D. B3
E. C
203.
For treatment of the patient with acute pancreatitis a doctor prescribed a trasilol.
For what purpose used this preparation?
A. * To avoid of autolysis of pancreas
B. For the improvement of fats digestion
C. For the improvement of proteins digestion
D. For the increase of insulin secretion
E. All above are correct
204.
From the human blood serum were selected and discovered properties of five
isoenzyme forms of lactate dehydrogenase. What property of isoenzyme does prove that
the selected forms are the same enzyme?
A. Same molecular mass
B. * Catalyze the same reaction
C. Same physical and chemical properties
D. Tissue localisation
E. Same electrophoretic mobility
205.
Hairs, skin and eyes of a patient do not have a pigment. A diagnosis – albinism
was set. The deficiency of what enzyme does take place?
A. * Tyrosinase
B. Arginase
C. Carbanhydrase
D. Histidin decarboxylase
E. Aldolase
206.
In a stomach of new-born takes place transformation of soluble of milk proteins caseins into insoluble protein - paracasein with participation of calcium ions and enzyme.
What enzyme does take part in this process?
A. * Rennin
B. Pepsin
C. Gastrin
D. Secretin
E. Lipase
207.
In an organism was found the lack of iron. It will cause the decrease of such
enzyme activity:
A. Glutation peroxidase
B. Carboanhydrase
C. Carboxypeptidase
D. Ceruloplasmin
E. * Catalase
208.
In an organism was found the lack of copper. It will cause the decrease of such
enzyme activity:
A. Cytochrome b
B. Glucose oxidase
C. Catalase
D. * Cytochrome oxsidase
E. Glutation peroxidase
209.
In blood and urine of a patient it was takes place increase value of pyruvic and
ketoglutaric acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
210.
In blood and urine of a patient it was takes place increase value of pyruvic and ?ketoglutaric acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
211.
In blood of a patient were found out the decline of activity of amino transferases
and decarboxylases of amino acids. Which coenzyme preparation may be recommended
for this patient?
A. Thiamin pyrophosphate
B. FAD
C. * Pyridoxal phosphate
D. NAD
E. Ubiqinon
212.
In blood of patient found out the increase of activity of LDH1, LDH2, AsAT,
creatin phosphokinase - MB. In what organ disorders of biochemical processes takes
place?
A. Pancreas
B. Skeletal muscles
C. Kidneys
D. Liver
E. * Heart
213.
In bloodof the patient concentration of acetaldehyde is increased, and causes
disgust of an alcohol. What preparation - the inhibitor of aldehyde dehydrogenase is used
in medical practice for the prophylaxis of alcoholism?
A. Ethanol.
B. * Teturam.
C. Trasilol
D. Aldehyde
E. Methanol
214.
In medical practice for treatment of festering wound enzymes preparations are
used. Which from the below mentioned enzymes is used in such cases?
A. * Trypsin
B. Alkaline phosphatase
C. Acidic phosphatase
D. Amylase
E. Arginase
215.
In poison of some snakes there is an enzyme which in a human organism can
result in formation of substances with a hemolytic action. Choose it.
A. * Phospho lipase A2
B. Lipase A1
C. Lipase C
D. Phospho lipase D
E. Phospho lipase B
216.
increase in which of the LDH isoenzyme fraction?
A. LDH-1
B. LDH-1 and LDH-2
C. * LDH-3 and LDH-4
D. LDH-2 and LDH-3
E. LDH-5
217.
It was determinate high activity of amylase in a patient’s saliva . How properly
interpret this analysis?
A. * ParotitisIt is possible.
B. Pathology of liver.
C. This analysis testifies disorders of gastrointestinal tract.
D. It is possible at nephropathies
E. This analysis testifies disorders of carbohydrate metabolism in an organism.
218.
It was determinate high activity of amylase in urine of a patient. How properly
interpret this analysis?
A. * It is possible acute pancreatitis, parotitis.
B. Pathology of liver.
C. This analysis testifies disorders of gastrointestinal tract.
D. It is possible at nephropathies
E. This analysis testifies disorders of carbohydrate metabolism in an organism.
219.
It was determine high activity of amylase in urine of a patient. How properly
interprete this analysis?
A. * It is possible acute pancreatitis, parotitis.
B. Pathology of liver.
C. This analysis testifies disorders of gastrointestinal tract.
D. It is possible at nephropathies
E. This analysis testifies disorders of carbohydrate metabolism in an organism.
220.
It was established that at parodontitis the secretion of kallikrein is increased.
Choose, what does increase inflammatory reaction in an oral cavity as result the of this
enzyme action?
A. Trasilol
B. * Kinins
C. Secretory immunoproteins
D. Lysozyme
E. Factor of nerves growth
221.
New antibiotics are synthesized with fermentative transformations of natural
antibiotics. What from the below named forms of enzymes are widely used in
pharmaceutical industry?
A. * Immobilized enzymes
B. Native enzymes
C. Denaturized enzymes
D. Complex of enzyme with a coenzyme
E. Complex of enzyme with an activator
222.
On which day following acute myocardial infarction the estimation of serum AST
willbe of greatest significance?
A. First day
B. * Second day
C. Third day
D. Fourth day
E. None of the above
223.
Organism suffers from hypovitaminosis of B5. How will it change the function of
oxidoreductases?
A. It will inhibit synthesis and functions of cytochroms
B. It will inhibit synthesis and functions of FMN and FAD – dependent
dehydrogenases
C. It causes improper synthesis and functions of TPP, which is the coenzyme of
pyruvate dehydrogenase.
D. It causes inhibition of synthesis and functions of aminotransferases.
E. * It causes inhibition of synthesis and functions of NAD and NADP – dependent
oxidoreductases (dehydrogenases)
224.
Parotitis of the patient was diagnosed. Determination of which from the below
mentioned enzymes in blood can be a diagnostic criteria?
A. LDH
B. Aldolase
C. * Amylases
D. Creatin kinase
E. Alanine amino peptidase
225.
released in plasma?
A. Kidney, R.B.C and Liver
B. * Heart, Kidney and R.B.C
C. Heart, Kidney and Liver
D. Heart, Lungs and Brain
E. All of the above
226.
Salivary amylase is an enzyme in humans that breaks down starch. The optimum
pH for this reaction is 6.7. The rate of this reaction would not be affected by
A. * Maintaining the pH of the reaction at 6.7
B. Substrate concentration
C. Enzyme concentration
D. Decreasing the temperature of the reaction by 5oC
E. Maintaining the pH of the reaction at 7.7
227.
Teturam which is the inhibitor of aldehyde dehydrogenase used in medical
practice for the prophylaxis of alcoholism. An increase in blood of what metabolite
causes disgust of an alcohol?
A. malonic aldehyde
B. Ethanol
C. * Acetaldehyde
D. Proponic aldehyde
E. Methanol
228.
The analysis demonstrated a 10 times increase of diastase activity. The danger of
autolysis of a patient’s pancreas caused with activating of enzyme:
A. Amylase
B. Pepsin
C. * Trypsin
D. Lipase
E. Nuclease
229.
The analysis demonstrated a 10 times increase of diastase activity. The danger of
autolysis of a patient’s pancreas caused with activating of enzyme:
A. Amylase
B. Pepsin
C. * Trypsin
D. Lipase
E. Nuclease
230.
The functional state of liver, effectiveness of treatment and prognosis of disease
development, estimate by such biochemical indexes of blood and urine, except:
A. AlAT
B. Gamma-glutamintranspeptidase
C. Alkaline phosphatase
D. Contents of albumins and globulins
E. * Diastase
231.
?The inherited genetic defects result in violation of synthesis of some enzymes in
the human organism. The defect of which enzyme results in disorders of splitting of
lactose:
A. * Lactase
B. Maltase
C. Sucrase
D. Amylase
E. Peptidase
232.
The patient with cyanide poisoning was delivered to clinic. What mast be
immediately used for the improvement of his state?
A. Glucose
B. Ascorbic acid
C. * Cytochromoxidase
D. Vitamin B1
E. Nicotine amide
233.
The рН of children’s gastric juice is of 4,0-5,0. Name the enzyme of gastric juice
which is active in this conditions.
A. * Rennin
B. Pepsin
C. Trypsin
D. Elastase
E. Chymotrypsin
234.
Trypsin
A. * Arginase
B. Catalase
C. Alkaline phosphatase
D. Acidic phosphatase
235.
Viral hepatitis of a 5 years old child is suspected. Which from below mentioned
indexes is it necessary to define for confirmation of diagnosis?
A. LDH2
B. LDH1
C. AsAT
D. * AlAT
E. Creatin kinase
236.
Vomiting, diarrhea after consuming milk, enlargement of the liver, jaundice,
cirrhosis,cataracts, retardation of the mental development, elevated blood-galactose level,
absence of the galactose 1-phosphate uridyl transferase in red blood cells are the
symptoms of:
A. lactose intolerance
B. hypolactasia
C. * galactosemia
D. all of the above
E. diabetes mellitus
237.
With ageing in cartilaginous decreases intensity of proteoglycans formation that
leads to diminishing of degree of their hydratation and loss of tissues turgor. Activity of
what enzymes of lysosomes does increase?
A. Deaminase, decarboxylase
B. Isomerase, dehydrogenases
C. Protease, lipase
D. Oxidoreductases, phosphstase
E. * Cathepsins, glycosidase
238.
With urine of newborn was done a reaction with FeCI3 and a positive reaction
(dark color) got. What disease is possible?
A. Galactosemia
B. Tirosinosis
C. * Phenylketonuria
D. Alkaptonuria
E. Aminoaciduria.
239.
With urine of newborn was done a reaction with FeCI3 and a positive reaction
(dark color) got. What disease is possible?
A. Galactosemia
B. Tirosinosis
C. * Phenylketonuria
D. Alkaptonuria
E. Aminoaciduria
240.
A reaction can occur spontaneously only if G, the change in free energy of
products and reactants, is:
A. positive;
B. * negative;
C. 0;
D. all reactions can occur spontaneously.
E. all of the above.
241.
All of the following compounds are intermediates of TCA cycle except
A. Malate
B. * Pyruvate
C. Oxaloacetate
D. Fumarate
E. ?-Ketoglutarate
242.
An aneplerotic reaction which sustains the availability of oxaloacetate is the
carboxylation of
A. Glutamate
B. * Pyruvate
C. Citrate
D. Succinate
E. All of the above
243.
If all the enzymes, intermediates and cofactors of the citric acid cycle as well as
an excess of the starting substrate acetyl-CoA are present and functional in an organelle
free solution at the appropriate pH, which of the following factors of the citric acid cycle
would prove to be rate limiting?
A. Molecular oxygen
B. Half life of enzyme
C. Turnover of intermediates
D. * Reduction of cofactors
E. All of theese
244.
In TCA cycle, oxalosuccinate is converted to ?-ketoglutarate by the enzyme:
A.
B.
C.
D.
E.
Fumarase
* Isocitrate dehydrogenase
Aconitase
Succinase
?-ketoglutarate dehydrogenase
245.
Most of the metabolic pathways are either anabolic or catabolic. Which of the
following pathways is considered as “amphibolic” in nature?
A. Glycogenesis
B. Glycolytic pathway
C. Lipolysis
D. * TCA cycle
E. All of these
246.
Out of 24 mols of ATP formed in TCA cycle, 2 molecules of ATP can be formed
at “substrate level” by which of the following reaction ?
A. Citric acid>?Isocitric acid
B. Isocitrate>?Oxaloacetate
C. Succinic acid>?Fumarate
D. * Succinyl>?Succinic acid
E. Both A and D
247.
Pyruvate dehydrogenase contains all except
A. * Biotin
B. NAD
C. FAD
D. CoA
E. Lipoic acid
248.
The enzyme ?-ketoglutarate dehydrogenase in the citric acid cycle requires
A. * Lipoate
B. Folate
C. Pyridoxine
D. Inositol
E. NADP
249.
The reaction catalysed by ?-ketoglutarate dehydrogenase in the citric acid cycle
requires
A. * NAD
B. NADP
C. ADP
D. ATP
E. PLP
250.
A distinct set of metabolic reactions is called a reaction ________________.
A. Network
B. Cycle
C. * Pathway
D. Mechanism
E. A and B
251.
A specific inhibitor for succinate dehydrogenase is
A. Arsinite
B. * Melouate
C. Citrate
D. Cyanide
252.
A specific inhibitor for succinate dehydrogenase is
A. Arsinite
B. * Malouate
C. Citrate
D. Cyanide
E. All of these
253.
Acetyl CoA _________ pyruvate dehydrogenase complex and NADH
__________ it.
A. activates; activates
B. activates; inhibits
C. * inhibits; inhibits
D. inhibits; activates
E. nome of the above
254.
Acetyl CoA _________ pyruvate dehydrogenase complex and NADH
__________ it.
A. activates; activates
B. activates; inhibits
C. * inhibits; inhibits
D. inhibits; activates
E. nome of the above
255.
Aerobic oxidation of pyruvate to CO2 and H2O results in formation of molecules
ATP:
A. 38 ATP
B. 12 ATP
C. 3 ATP
D. * 15 ATP
E. 2 ATP
256.
After passing through the citric acid cycle, one mole of pyruvate will result in the
formation of ______ moles of carbon dioxide and _________ mole(s) of ATP (or GTP).
A. 2; 2
B. 2; 1
C. 3; 2
D. * 3; 1
E. 1; 3
257.
All enzymes and coenzymes of the pyruvate dehydrogenase complex are located
in:
A. cytoplasm;
B. * matrix of mitochondria;
C. lysosomes;
D. partially in cytoplasm, partially in mitochondrial matrix.
E. all of the above
258.
All of the following are allosteric enzymes except
A. Citrate synthetase
B. ?-Ketoglutarate dehdrogenase
C. * Succinate thiokinase
D. Succinate dehydrogenase
E. Both B and C
259.
All of the following are intermediates of citric acid cycle except
A. Oxalosuccinate
B. Oxaloacetate
C. * Pyruvate
D. Fumarate
E. ?-Ketoglutarate
260.
All of the following intermediates of citric acid cycle can be formed from amino
acids except
A.
B.
C.
D.
E.
?-Ketoglutarate
Fumarate
* Malate
Oxaloacetate
B and C
261.
Allosteric effector of enzymes of Krebs cycle which stimulate their oxidation is:
A. Succinate
B. * NAD+
C. NADH2
D. ATP
E. FADH2
262.
Allosteric effector of enzymes of Krebs cycle which stimulate their oxidation is:
A. Succinate
B. * NAD+
C. NADH2
D. ATP
E. FADH2
263.
An allosteric enzyme responsible for controlling the rate of T.C.A cycle is
A. Malate dehydrogenase
B. * Isocitrate dehydrogenase
C. Fumarase
D. Aconitase
E. All of the above
264.
An allosteric enzyme responsible for controlling the rate of T.C.A cycle is
A. Malate dehydrogenase
B. * Isocitrate dehydrogenase
C. Fumarase
D. Aconitase
E. Both A and B
265.
An amphibolic pathway among the following is
A. HMP shunt
B. Glycolysis
C. * Citirc acid cycle
D. Gluconeogenesis
E. All of these
266.
An aneplerotic reaction which sustains the availability of oxaloacetate is the
carboxylation of
A. Glutamate
B. * Pyruvate
C. Citrate
D. Succinate
E. Lactate
267.
An enzyme of the citric acid cycle also found outside the mitochondria is
A. Isocitrate dehydrogenase
B. Citrate synthetase
C. * ?-Ketoglutarate dehydrogenase
D. Malate dehydrogenase
E. All of the above
268.
Anabolic and catabolic reactions in eukaryotes can occur simultaneously in cells.
This is possible because _______.
A. they all occur in the cytosol
B. the anabolic and catabolic pathways do not share any intermediate metabolites
C. * of the compartmentation of metabolites for the reactions of the opposing
pathways
D. all catabolic reactions are exergonic and all anabolic reactions are endergonic
E. they all occur in the mitochondria
269.
Carbons from acetyl CoA are transferred to the citric acid cycle. Which is the first
round of the citric acid cycle that could possibly release a carbon atom originating from
this acetyl CoA?
A. first round
B. * second round
C. third round
D. fourth round
E. fifth round
270.
Catabolism is a form of metabolism in which molecules are converted into
A. * Simple end product, energy
B. Large start product
C. Peptides, protein
D. Food, storage
E. All of the above
271.
Catabolism is characterized by _______________ of three major routs toward a
final common pathway.
A. divergence;
B. * convergence;
C. splitting;
D. none of the above.
E. all of the above.
272.
Central intermediate product of all of metabolism is:
A. * Acetyl-CoA
B. Succinyl-CoA
C. Oxaloacetate
D. Pyruvate
E. Citrate
273.
Citrate has a positive allosteric effect on which one of the following enzymes?
A. Pyruvate kinase
B. * Acetyl CoA carboxylase
C. Phosphofructokinase
D. Fatty acid synthetase
E. Enolase
274.
Citrate is converted to isocitrate by aconitase which contains
A. Ca++
B. * Fe++
C. Zn++
D. Mg++
E. Both A and B
275.
Citrate is converted to isocitrate by aconitase which contains
A. Ca++
B. * Fe++
C. Zn++
D. Mg++
E. All of the above
276.
Cofactors of dehydrogenases are all, except one:
A. NAD+
B. * c-AMP
C. NADP+
D. FMN
E. FAD
277.
Consider the synthesis of a biopolymer in which the addition of successive
monomers occurs by the same kind of reaction(s). The synthesis of the polymer is a
________ pathway.
A. Linear
B. Cyclic
C. * Spiral
D. Branched
E. A and B
278.
During succinyl CoA synthetesis generates
A. An energy deficient, unstable phosphoenzyme intermediate
B. An energy rich, unstable phosphoenzyme intermediate
C. * An energy rich, stable phopsphoenzyme intermediate
D. An energy deficient, stable phosphoenzyme intermediate
E. All of the above
279.
Each of the following catalyzed reactions of the citric acid cycle appears to be
metabolically irreversible except:
A. Citrate synthase
B. * Fumarase
C. Isocitrate dehydrogenase
D. Alpha ketoglutarate dehydrogenase complex
E. None of the above
280.
Each of the following leads to a biosynthetic pathway except:
A. Alpha ketoglutarate
B. Succinyl CoA
C. Oxaloacetate
D. Citrate
E. * None of the above
281.
Energy in biological systems is primarily
A. Electrical
B. * Chemical
C. Radiant
D. Mechanical
E. A and D
282.
Energy is carried from catabolic to anabolic reactions in the form of
A. ADP
B. * High-energy ATP bonds
C. Coenzymes
D. Inorganic phosphate
E. Oxygen
283.
Energy requiring metabolic pathways that yield complex molecules from simpler
precursors are:
A. Amphibolic.
B. * Anabolic.
C. Autotrophic.
D. Catabolic.
E. Heterotrophic.
284.
Fluoroacetate inhibits the reaction of citric acid cycle:
A. Isocitrate ?-Ketoglutarate
B. Fumarate -Malate
285.
286.
287.
288.
289.
290.
291.
292.
C. * Citrate -cis-aconitate
D. Succinate –fumarate
E. All of these
For one turn of Krebs cycle forms ATP (molecules):
A. 38 ATP
B. * 12 ATP
C. 15 ATP
D. 1 ATP
E. 15 ATP
Formation of succinyl-CoA from ?-Ketoglutarate is inhibited by
A. Fluoroacetate
B. * Arsenite
C. Fluoride
D. Iodoacetate
E. All of these
In citric acid cycle, NAD is reduced in
A. One reactions
B. Two reactions
C. * Three reactions
D. Four reactions
E. Five reactions
In eukaryotes the enzymes of the citric acid cycle are found in the _________.
A. cytosol
B. * mitochondria
C. nucleus
D. endoplasmic reticulum
E. both A and B
In eukaryotes the enzymes of the citric acid cycle are found in the _________.
A. cytosol
B. * mitochondria
C. nucleus
D. endoplasmic reticulum
E. all of these
Isocitrate dehydrogenase is allosterically inhibited by
A. Oxalosuccinate
B. ?-Ketoglutarate
C. * ATP
D. NADH
E. Both B and C
Malonate
A. Is a structural analogy of succinate
B. Binds to the substrate binding site of the succinate dehydrogenase complex but
does not react
C. Undergoes an oxidation reaction
D. * Both a and b
E. All of the above
Malonate is an inhibitor of
A. Malate dehydrogenase
B. ?-ketoglutarate dehydrogenase
C. * Succinate dehydrogenase
D. Isocitrate dehydrogenase
E. Both C and D
293.
Most of the metabolic pathways are either anabolic or catabolic. Which of the
following pathways is considered as “amphibolic” in nature?
A. Glycogenesis
B. Glycolytic pathway
C. Lipolysis
D. * TCA cycle
294.
NAD-dependent malate dehydrogenase
A. Catalyzes the oxidation of malate to regenerate oxaloacetate
B. Catalyzes the conversion of fumarase to malate
C. Catalyzes a reaction which results in the formation of an NADH molecule
D. All of the above
E. * a and c only
295.
One molecule of glucose gives ______molecules of CO2 in TCA cycle.
A. * 6
B. 3
C. 1
D. 2
E. 12
296.
Oxidative decarboxylation of pyruvate requires
A. NADP+
B. Cytichromes
C. pyridoxal phosphate
D. * COASH
E. All of the above
297.
Oxidative decarboxylation of pyruvate requires
A. NADP+
B. Cytochromes
C. pyridoxal phosphate
D. * CoASH
E. Pyridoxine
298.
Oxidative degradation of acetyl coenzyme A (CoA) in the citric acid cycle gives a
net yield of which of the following chemicals?
A. Flavin adenine dinucleotide (FADF)
B. Nicotinamide adenine dinucleotide (NADN)
C. Adenosine triphosphate (ATP)
D. Guanosine diphosphate (GDP)
E. * Carbon dioxide (CO2)
299.
Please match the following reaction Malate dehydrogenase to its respective
energy yielding products shown in answers A through E.
A. * NADH
B. QH2
C. GTP or ATP
D. ADP
E. NAD
300.
Please match the following reaction Succinate dehydrogenase complex to its
respective energy yielding products shown in answers A through E.
A. NADH
B. * QH2
C. GTP or ATP
D. ADP
E. NAD
301.
Please match the following reaction Succinyl CoA synthetase to its respective
energy yielding products shown in answers A through E.
A. NADH
B. QH2
C. * GTP or ATP
D. ADP
E. NAD
302.
Please match the following reaction Alpha ketoglutarate dehydrogenases complex
to its respective energy yielding products shown in answers A through E.
A. * NADH
B. QH2
C. GTP or ATP
D. ADP
E. NAD
303.
Please match the following reaction Isocitrate dehydrogenase to its respective
energy yielding products shown in answers A through E.
A. * NADH
B. QH2
C. GTP or ATP
D. ADP
E. NAD
304.
Product of a pathway controls the rate of its own synthesis by inhibiting an early
step. Such way of enzyme regulation is called:
A. * feedback inhibition;
B. feed-forward activation;
C. autoregulation;
D. none of the above.
E. feedback activation
305.
Product of a pathway controls the rate of its own synthesis by inhibiting an early
step. Such way of enzyme regulation is called:
A. * feedback inhibition;
B. feed-forward activation;
C. autoregulation;
D. none of the above.
E. feedback activation
306.
Prosthetic group of cytochrome is:
A. FAD
B. Ubiqinon
C. Biotin
D. * Iron porphyryn complex
E. Cooper contain porphyryn complex
307.
Pyruvate can be form from all substrates, except one:
A. Lactate
B. Glycerol
C. Glucose
D. * Fatty acids
E. Glycogen
308.
Pyruvate dehydrogenase complex and ?-ketoglutarate dehydrogenase complex
require the following for their oxidative decarboxylation:
A. COASH and Lipoic acid
B. NAD+ and FAD
C. COASH and TPP
D. * COASH, TPP,NAD+,FAD, Lipoate
E. COASH, TPP, FAD, Lipoate
309.
Substrates of the respiratory chain are all, except one:
A. Isocitrate
B. Malate
C. * Oxaloacetate
D. Succinate
E. E-кеtoglutarate
310.
Substrates of the respiratory chain are all, except one:
A. Isocitrate
B. Malate
C. * Oxaloacetate
D. Succinate
E. E-кеtoglutarate
311.
Substrates of the respiratory chain are all, except one:
A. Isocitrate
B. Malate
C. C-кеtoglutarate
D. Succinate
E. * Lactate
312.
The activity of pyruvate carboxylase is dependent upon the positive allosteric
effector
A. Succinate
B. AMP
C. Isocitrate
D. Citrate
E. * Acetyl CoA
313.
The carrier of the citric acid cycle is
A. Succinate
B. Fumarate
C. Malate
D. * Oxaloacetate
E. All of these
314.
The carrier of the citric acid cycle is
A. Succinate
B. Fumarate
C. Malate
D. * Oxaloacetate
E. All of the above
315.
The citric acid cycle is inhibited by which of the following?
A. * Fluoroacetate
B. Fluorouracil
C. Aerobic conditions
D. Arsenic
E. Malic acid
316.
The citric acid cycle is the _________________________________________.
A. * final common pathway for the catabolism of fuel molecules — carbohydrates,
fatty acids and amino acids;
B. the anabolic pathway in which macromolecules are synthesized from monomers;
C. the biochemical pathway in which glucose is oxidized to acetyl CoA;
D. the biochemical pathway in which glucose is synthesized from noncarbohydrate
components.
E. final common pathway for the catabolism of carbohydrates;
317.
The citric acid cycle oxidizes pyruvate and some of the pathway intermediates are
starting materials for many biosynthetic pathways. This means the citric acid cycle is a/an
______________.
A. amplifying pathway
B. strictly catabolic pathway
C. anaerobic pathway
D. * amphibolic pathway
E. both A and D
318.
The citric acid cycle oxidizes pyruvate and some of the pathway intermediates are
starting materials for many biosynthetic pathways. This means the citric acid cycle is a/an
______________.
A. amplifying pathway
B. strictly catabolic pathway
C. anaerobic pathway
D. * amphibolic pathway
319.
The cycle of tricarboxilic acids begins with the reaction of substrates:
A. Pyruvate and acetyl CoA
B. Citric acid and acetyl CoA
C. * Oxaloacetate and acetyl CoA
D. Succinate and isocitrate
E. Isocitrate and oxaloacetate
320.
The decarboxylation of pyruvate produces
A. NADH
B. Acetyl
C. CO2
D. ATP
E. * A, b, and c
321.
The degradation of which class of biochemicals does not significantly contribute
to the release of energy to cells?
A. * Nucleic acids
B. Proteins
C. Lipids
D. Carbohydrates
E. B and C
322.
The degradative Processess are categorized under the heading of
A. Anabolism
B. * Catabolism
C. Metabolism
D. All of these
E. None of the above
323.
The entry point into the citric acid cycle for isoleucine, valine, and the product of
odd-chain fatty acids is
A. Fumarate
B. Pyruvate
C. * Oxaloacetate
D. Citrate
E. Succinyl CoA
324.
The enzyme pyruvate translocase is located ______________.
A. in the cytosol
B. * in the inner mitochondrial membrane
C. in the mitochondrial matrix
D. in the endoplasmic reticulum
325.
The enzymes of the citric acid cycle are located in
A. * Mitochondrial matrix
B. Extramitochondrial soluble fraction of the cell
C. Nucleus
D. Endoplasmic reticulum
E. Mitochondrial membrane
326.
The enzymes of the Krebs cycle are located in the
A. * Cytoplasm
B. Inter-membrane space of mitochondria
C. Vesicles of the ER
D. Outer membrane of the mitochondria
E. Matrix of the mitochondria
327.
The example of generation of a high energy phosphate at the substrate level in the
citric acid cycle is the reaction:
A. Isocitrate >?-Ketoglutarate
B. Succinate > fumarate
C. Malate > oxaloacetate
D. * Succinyl CoA > Succinate
E. Both A and D
328.
The flow of material through a reaction pathway usually depends on
________________.
A. * Control at several steps in the pathway
B. Control of the first step of the pathway
C. Covalent modification of the enzyme that catalyzes the reaction
D. Feed-forward activation
E. Control of the second step of the pathway
329.
The flow of material through a reaction pathway usually depends on
________________.
A. * Control at several steps in the pathway
B. Control of the first step of the pathway
C. Covalent modification of the enzyme that catalyzes the reaction
D. Feed-forward activation
E. Control of the second step of the pathway
330.
The following co-enzyme is needed for the oxidative decarboxylation of
ketoacids:
A. NADP+
B. TPP
C. Folate coenzyme
D. Biotin coenzyme
E. None of these
331.
The following coenzyme is needed for the oxidative decarboxylation of ketoacids:
A. NADP+
B. * TPP
C. Folate coenzyme
D. Biotin coenzyme
E. Both B and C
332.
The function of protein kinase is:
A. synthesis of ATP from two ADP molecules;
B. catalysis of the oxidation-reduction reactions;
C. * phosphorylation of proteins (enzymes);
D. dephosphorylation of proteins (enzymes).
E. none of the above.
333.
The initial step of the citric acid cycle is
A. Conversion of pyruvate to acetyl-CoA
B. * Condensation of acetyl-CoA with oxaloacetate
C. Conversion of citrate to isocitrate
D. Formation of ??-ketoglutarate catalysed by isocitrate dehydrogenase
E. Both A and B
334.
The list of cofactors which are able in the process of fermentative reactions to
carry electrons and protons is below resulted, except of one cofactor which carries
chemical groups only. Choose it:
A. NAD
B. * Pyridoxal phosphate
C. FAD
D. Ubiqinon (coenzyme Q)
E. Hem coenzymes
335.
The number of molecules of ATP produced by the total oxidation of acetyl CoA
in TCA cycle is
A. 6
B. 8
C. 10
D. * 12
E. 15
336.
The oxidation of acetyl CoA in citric acid cycle to CO2 and water is the
_________ stage of catabolism and this is ___________ stage.
A. first, specific;
B. second, nonspecific;
C. third, specific;
D. * third, nonspecific.
E. second, specific.
337.
The process by which a cell is built up from the simple nutrients obtained from its
environment is called _____.
A. * Anabolism
B. Biosynthesis
C. Catabolism.
D. All of the above
E. More than one of the above, but not all
338.
The reaction Pyruvate + CO2 + ATP + H2O ( Oxaloacetate + ADP + Pi is the
example of ____________ reactions that ____________citric acid cycle intermediates.
A. anaplerotic; replenish;
B. catabolic; remove;
C. anabolic; remove;
D. * anaplerotic; remove.
E. all of the above
339.
The reaction of Kreb’s cycle which does not require cofactor of vitamin B group
is
A. * Citrate > isocitrate
B. ??-Ketoglutarate > succinate
C. Malate > oxaloacetate
D. Succinate > fumarate
E. Both A and D
340.
The reaction succinyl CoA to succinate requires
A. CDP
B.
C.
D.
E.
* ADP
GDP
NADP+
TPP
341.
The reaction succinyl COA to succinate requires
A. CDP
B. * ADP
C. GDP
D. NADP+
E. All of the above
342.
The second stage of aerobic oxidation of glucose in a cell is oxidative
decarboxilation of pyruvate. Name the main product of this proces.
A. * Acetyl CoA
B. Succinate
C. Pyruvate
D. Citrate
E. Oxaloacetate
343.
The second stage of aerobic oxidation of glucose in a cell is oxidative
decarboxilation of pyruvate. Name the main product of this proces.
A. Acetyl CoA
B. * Succinate
C. Pyruvate
D. Citrate
E. Oxaloacetate
344.
The step at which acetyl CoA enters the citric acid cycle is classified as a
___________ reaction.
A. * condensation
B. substrate-level phosphorylation
C. decarboxylation
D. dehydrogenation
E. oxidative phosphorylation
345.
The step at which ATP releases in the citric acid cycle is classified as a
___________ reaction.
A. condensation
B. * substrate-level phosphorylation
C. decarboxylation
D. dehydrogenation
E. oxidative phosphorylation
346.
The step at which CO2 releases in the citric acid cycle is classified as a
___________ reaction.
A. condensation
B. substrate-level phosphorylation
C. * decarboxylation
D. dehydrogenation
E. oxidative phosphorylation
347.
The substance which may be considered to play a catalytic role in citric acid cycle
is
A. * Oxaloacetate
B. Isocitrate
C. Malate
D. Fumarate
E. Succinyl CoA
348.
A.
B.
C.
D.
E.
349.
A.
B.
C.
D.
E.
350.
A.
B.
C.
D.
E.
The succinate dehydrogenase complex catalyzes
The formation of a single hydrogen bond in the oxidation of succinate to fumarate
* The formation of a double bond in the oxidation of succinate to fumarate
Both a and b
The formation of a macroergic bond
None of the above
The TCA cycle:
Is found in the cytosol
* Is controlled by calcium ion, the ADP/ATP ratio, and the NADH concentration
Is also called the Cori cycle
Consumes most of the CO2 produced by ribosomes
Produces most of the water made in humans
The temperature of human body supported due to all of processes, except one:
Katabolism of proteinsns, lipids, carbohydrates (specific stage)
Glycolysis
Katabolism (general stage)
TCA and oxidative phosphorylating
* Gluconeogenesis
The transfer of free energy from catabolic pathways to anabolic pathways is best
351.
called
A. Feedback regulation.
B. Bioenergetics.
C. Cooperativity.
D. * Energy coupling.
E. Entropy.
352.
There are ____ enzymes in the pyruvate dehydrogenase complex and ____
coenzymes: _______________________________________________.
A. 5; 5: TPP, lipoamide, HS-CoA, FAD+, NAD+
B. * 3; 5: TPP, lipoamide, HS-CoA, FAD+, NAD+
C. 3; 5: PLP, lipoamide, HS-CoA, FAD+, NADP+
D. 4; 5: PLP, lipoamide, HS-CoA, FAD+, NADP+
E. 5; 5: PLP, lipoamide, HS-CoA, FAD+, NADP+
353.
There are 4 main functions of Krebs cycle, except:
A. Oxidation of acetic acid into СО2 і Н2О
B. Donator of hydrogen atoms for respiratory chain
C. * Oxidation of lactate into pyruvate
D. Formation of ATP
E. Supplying substrates for heme synthesis
354.
There are 4 main functions of Krebs cycle, except:
A. Oxidation of acetic acid into СО2 і Н2О
B. * Donator of hydrogen atoms for respiratory chain
C. Oxidation of lactate into pyruvate
D. Formation of ATP
E. Supplying substrates for heme synthesis
355.
There are such three enzymes in pyruvate dehydrogenase complex:
A. Pyruvate carboxylase, lactate dehydrogenase, citrate synthase
B. * Pyruvate dehydrogenase, dihydrolipoyl acetyl transferase, dihydrolipoyl
dehydrogenase.
C. Ketoglutarate dehydrogenase, acetyltransferase, aconitase
D. NАDН2- dehydrogenase
E. Succinate dehydrogenase, aldehyde dehydrogenase.
356.
Tricarboxylic acid cycle to be continuous requires the regeneration of
A.
B.
C.
D.
E.
Pyruvic acid
* oxaloacetic acid
?-oxoglutaric acid
Malic acid
Fatty acids
357.
Tricarboxylic acid cycle to be continuous requires the regeneration of
A. Pyruvic acid
B. * oxaloacetic acid
C. ?-oxoglutaric acid
D. Malic acid
E. Fumaric acid
358.
Unlike NADH and NADPH, FAD and FADH
A. Donate one electron at a time
B. Donate one or two electrons at a time
C. Do not become positively charged
D. a and c
E. * b and c
359.
Where in a cell the tricarboxylic acid cycle takes place?
A. Within the inner compartment of the mitochondrion.
B. * In cytoplasm.
C. In nucleus.
D. In ribosomes.
E. All of these
360.
Which 5-carbon intermediate of the citric acid cycle is converted to a 4-carbon
molecule with the release of carbon dioxide?
A. fumarase
B. * а-ketoglutarate
C. succinate
D. isocitrate
E. citrate
361.
Which carbon atom(s) of pyruvate is(are) first converted to carbon dioxide by
pyruvate dehydrogenase complex?
A. * the carboxylate carbon (#1)
B. the carbonyl carbon (#2)
C. the methyl carbon (#3)
D. both carbons #1 and #3 in equal amounts
E. all of the above
362.
Which cofactor is not used by the pyruvate dehydrogenase complex?
A. lipoamide
B. thiamine pyrophosphate
C. FAD
D. * QH2
E. HS-CoA
363.
Which cofactor is not used by the pyruvate dehydrogenase complex?
A. lipoamide
B. thiamine pyrophosphate
C. FAD
D. * NAD
E. PLP
364.
Which enzyme catalyzes a metabolically irreversible reaction?
A. aconitase
B. * isocitrate dehydrogenase
C. fumarase
D. malate dehydrogenase
E. All of the above
365.
Which enzyme catalyzes a reaction that releases carbon dioxide?
A. a-ketoglutarate dehydrogenase complex
B. pyruvate dehydrogenase
C. * malate dehydrogenase
D. aconitase
E. both A and B
366.
Which enzyme catalyzes the citrate synthesis?
A. aldolase
B. * citrate synthase
C. citrate isomerase
D. aconitase
E. citrate dehydrogenase
367.
Which enzyme catalyzes the conversion of citrate to isocitrate?
A. aldolase
B. citrate synthase
C. citrate isomerase
D. * aconitase
E. epimerase
368.
Which enzyme does not catalyze a reaction that releases carbon dioxide?
A. A-ketoglutarate dehydrogenase complex
B. pyruvate dehydrogenase
C. * malate dehydrogenase
D. isocitrate dehydrogenases
E. both A and C
369.
Which enzyme does not catalyze a reaction that releases carbon dioxide?
A. a-ketoglutarate dehydrogenase complex
B. pyruvate dehydrogenase
C. * malate dehydrogenase
D. isocitrate dehydrogenases
E. All of these
370.
Which enzyme is the same in both pyruvate dehydrogenase complex and aketoglutarate complex?
A. * dihydrolipoamide dehydrogenase
B. aconitase
C. pyruvate decarboxylase
D. The two complexes have no components that are similar
E. Both A and B
371.
Which enzyme is the same in both pyruvate dehydrogenase complex and аketoglutarate complex?
A. * dihydrolipoamide dehydrogenase
B. aconitase
C. pyruvate decarboxylase
D. The two complexes have no components that are similar.
E. Dihydrolipoamide kinase
372.
Which intermediate of the citric acid cycle has a plane of symmetry?
A. * succinate
B. citrate
C. succinyl CoA
D. а-ketoglutarate
E. all of these
373.
Which is not a component of the Alfa ketoglutarate dehydrogenase complex?
A. dihydrolipoamide dehydrogenase
B. Alfa ketoglutarate dehydrogenase
C. * pyruvate dehydrogenase
D. dihydrolipoamide acetyltransferase
E. All of the above
374.
Which is not a component of the pyruvate dehydrogenase complex?
A. dihydrolipoamide dehydrogenase
B. * isocitrate dehydrogenase
C. pyruvate dehydrogenase
D. dihydrolipoamide acetyltransferase
E. both B and D
375.
Which is not a component of the pyruvate dehydrogenase complex?
A. dihydrolipoamide dehydrogenase
B. * Alfa ketoglutarate dehydrogenase
C. pyruvate dehydrogenase
D. dihydrolipoamide acetyltransferase
E. All of the above
376.
Which is not produced by the citric acid cycle?
A. NADH
B. * FMN
C. CO2
D. FADH2
E. none of the above
377.
Which is usually the slowest way to regulate a reaction in a metabolic pathway?
A. Allosteric modulation
B. Covalent modification
C. * Changing the enzyme concentration
D. All of the above are usually equally as fast
E. Competitive inhibitor
378.
Which is usually the slowest way to regulate a reaction in a metabolic pathway?
A. Allosteric modulation
B. Covalent modification
C. * Changing the enzyme concentration
D. All of the above are usually equally as fast
E. Competitive inhibitor
379.
Which of the following allosterically activates mammalian isocitrate
dehydrogenase?
A. ADP
B. NADH
C. Calcium
D. All of the above
E. * a and c only
380.
Which of the following are components of the succinate dehydrogenase complex?
A. FAD prosthetic group
B. Iron-sulfur clusters
C. Malonate
D. All of the above
E. * a and b only
381.
Which of the following describe(s) some aspect of metabolism?
A. Breakdown of macromolecules
B.
C.
D.
E.
Synthesis of macromolecules
Control of enzyme activity
* A and B only
A, B, and C
382.
Which of the following is (are) true for anabolic pathways?
A. They do not depend on enzymes.
B. They are highly regulated sequences of chemical reactions.
C. * They consume energy to build up polymers from monomers.
D. They release energy as they degrade polymers to monomers.
E. Both B and C
383.
Which of the following is (are) true for anabolic pathways?
A. Catabolism involves the breakdown of energy-poor substrates into monomers.
Anabolism creates energy rich substrates from these monomers. Metabolism is
the sum of both of these processes
B. Catabolism is the breakdown of nutrients, anabolism is the generation of ATP.
Metabolism is the sum of both of these processes.
C. * Catabolism uses energy to breakdown nutrients into intermediates for
biosynthesis. Anabolism uses the intermediates for biosynthesis. Metabolism is
the sum of both of these processes.
D. Catabolism involves the multi-step breakdown of energy-rich nutrients into
smaller compounds; during this process energy is released. Anabolism uses the
energy released and the smaller compounds as intermediates for biosynthesis.
Metabolism is the sum of both of these processes
E. Anabolism involves the multi-step breakdown of energy-rich nutrients into
smaller compounds; during this process energy is released. Catabolism uses the
energy released and the smaller compounds as intermediates for biosynthesis.
Metabolism is the sum of both of these processes
F. They do not depend on enzymes.
G. They are highly regulated sequences of chemical reactions.
H. They consume energy to build up polymers from monomers.
I. They release energy as they degrade polymers to monomers.
J. Both B and C
384.
Which of the following is not a fate of a citric acid cycle intermediate?
A. Alpha ketoglutarate reversibly converting to glutamate
B. The biosynthesis of porphyrins from succinyl CoA's interaction with glycine
C. Oxabacetate as a carbohydrate precursor
D. * Acetyl CoA as fatty acids precursor
E. None of the above
385.
Which of the following is/are true statements about the succinate dehydrogenase
reactions?
A. * It is stereospecific
B. Only the cis-isomer of the product is formed
C. It is not stereospecific
D. Both b and c
E. Both a and b
386.
Which of the following metabolite integrates glucose and fatty acid metabolism?
A. * Acetyl CoA
B. Pyruvate
C. Citrate
D. Lactate
E. Fumarate
387.
Which of the following statements is false?
A.
B.
C.
D.
E.
Phosphofructokinase is the rate limiting enzyme in glycolysis
Phosphorylase activity is higher in Type II fibres than in Type I fibres
Endurance training increases the amount of TCA cycle enzymes in muscle
* Oxygen is consumed in the TCA cycle
The heart can oxidise lactate
388.
Which of the following statements is TRUE concerning catabolic pathways?
A. They build up complex molecules such as protein from simpler compounds.
B. They combine molecules into more complex and energy-rich molecules.
C. They are spontaneous and do not need enzyme catalysis.
D. They involve endergonic reactions that break complex molecules into simpler
ones.
E. * They are usually coupled with anabolic pathways to which they supply energy
in the form of ATP.
389.
Which of the following statements regarding T.C.A cycle is true?
A. It is an anaerobic process
B. It occurs in cytosol
C. It contains no intermediates for Gluconeogenesis
D. * It is amphibolic in nature
E. A and B
390.
Which of the following statements regarding T.C.A cycle is true?
A. It is an anaerobic process
B. It occurs in cytosol
C. It contains no intermediates for Gluconeogenesis
D. * It is amphibolic in nature
E. Both A and D
391.
Which of the following statements regarding the four "dehydrogenases" of the
TCA cycle is INCORRECT?
A. These are enzymes which remove electrons in the form of hydrogen from various
structures and transfer them to others
B. At least one catalyzes the "rate-limiting steps" of the TCA cycle
C. * GTP is generated from one of them via substrate level phosphorylation
D. NAD+ and FAD are the electron-accepting coenzymes for these enzymes
E. At least one catalyzes a reversible reactions
392.
Which statement does not explain why many biochemical processes are carried
out via multi-step pathways rather than by single-step reactions (or only a few steps)?
A. Multi-step pathways allow for more control points to regulate biochemical
processes.
B. * The end products of most pathways can usually be produced only by the
pathway reactions that nature has evolved.
C. Sharing of intermediates between pathways is facilitated this way.
D. There is greater control over the amounts of energy that are consumed or released
at any one time.
E. None of the above
393.
Which statement is false about most metabolic pathways?
A. * Most pathways are reversible under physiological conditions.
B. Pathways serve to increase the efficiency of energy transfers.
C. The rates of pathway reactions vary to respond to changing conditions.
D. The enzymes that catalyze reactions in metabolic pathways generally catalyze
only a single step.
E. Most pathways are irreversible under physiological conditions.
394.
Which statement is false about most metabolic pathways?
A. * Most pathways are reversible under physiological conditions.
B. Pathways serve to increase the efficiency of energy transfers.
C. The rates of pathway reactions vary to respond to changing conditions.
D. The enzymes that catalyze reactions in metabolic pathways generally catalyze
only a single step.
E. Most pathways are irreversible under physiological conditions.
395.
Which statement is not true about catabolic pathways?
A. They have a net release of energy.
B. * They have a net consumption of ATP.
C. They liberate smaller molecules from larger ones.
D. They include the citric acid cycle.
E. None of the above.
396.
Which statement is not true about catabolic pathways?
A. They have a net release of energy.
B. They have a net consumption of ATP.
C. They liberate smaller molecules from larger ones.
D. They include the citric acid cycl
E. A and C only
397.
Which step in the citric acid cycle is a rearrangement reaction?
A. succinyl CoA to succinate
B. fumarate to L-malate
C. * citrate to isocitrate
D. glucose 1,6-bisphosphate to fructose 1,6-bisphosphate
E. none of the above
398.
Which term most precisely describes the cellular process of breaking down large
molecules into smaller ones?
A. Dehydration
B. Catalysis
C. Anabolism
D. * Catabolism
E. Metabolism
399.
Which term most precisely describes the general process of breaking down large
molecules into smaller ones?
A. Anabolism
B. Catalysis
C. * Catabolism
D. Dehydration
E. Metabolism
400.
Why is ATP an important molecule in metabolism?
A. * It provides energy coupling between exergonic and endergonic reactions.
B. Its hydrolysis provides an input of free energy for exergonic reactions.
C. Its terminal phosphate group contains a strong covalent bond that when
hydrolyzed releases free energy.
D. A and B only
E. A, B and C
401.
Within the inner matrix of the mitochondrion are:
A. * The enzymes of the tricarboxylic acid cycle (Krebs’ cycle)
B. The components of the electron transport chain
C. Glycogen molecules
D. The enzymes of gluconeogenesis
E. The enzymes creatine kinase and carnitine acyl transferase 1
402.
Within the inner matrix of the mitochondrion are:
A. * The enzymes of the tricarboxylic acid cycle (Krebs’ cycle)
B.
C.
D.
E.
The components of the electron transport chain
Glycogen molecules
The enzymes of gluconeogenesis
The enzymes creatine kinase and carnitine acyl transferase 1
403.
The notion that ATP is generated by a proton gradient existing across a membrane
is called
A. Proton motion
B. Lactate reduction.
C. Cytochromic flow.
D. * Chemiosmotic theory.
E. Pyruvat decarboxilation
404.
?A biological redox potential of reaction always involves:
A. * А loss of electrons
B. A gain of electrons
C. A reducing agent
D. An oxidizing agent
E. All of the above
405.
A reaction that is facilitated by FADH2 is most likely a(n)
A. Oxidation
B. * Reduction
C. Hydrolysis
D. Isomerization
E. None of the above.
406.
All of the following molecules are directly involved in the electron transport chain
except
A. Coenzyme Q
B. O2
C. * Pyruvate
D. FADH2
E. Cytochrome c
407.
All of the following situations are consistent with active transport EXCEPT
A. The conversion of ATP to ADP accompanies the movement of molecules.
B. The rate of oxygen consumption by the cell increases when molecules move
C. Molecules move in or out of a cell against the osmotic gradient
D. Cells accumulate diffusible molecules in greater quantity than was found outside
the cell.
E. * The rate of movement of molecules across the cell membrane increases i an
anaerobic environment.
408.
An increase in the level of cellular ATP is likely to occur under which of the
following conditions?
A. * Increased activity of catabolic pathways
B. Decreased activity of anabolic pathways
C. Allosteric inhibition of anabolic pathways
D. A and B only
E. A, B, and C
409.
Antibiotic antimycin blocks electron transport in the span from:
A. NADH to Fe-S proteins
B. Cytochrom c to aa3
C. * NADH to ubiquinone
D. Cytochrome b to c
E. NADH to cytochrome b
410.
Compare the pH of the mitochondrial matrix and inner membrane space.
A.
B.
C.
D.
The pH is lower in the matrix.
The pH in both regions is the same.
* The pH is lower in the inner membrane space.
The comparison of pH varies from moment to moment depending on energy
needs of the cell.
E. A and B only
411.
Cyanide is a poison that blocks the passage of electons along the electron
transport chain. Which of the following is a metabolic effect of this poison?
A. The pH of the intermembrane space becomes much lower than normal
B. Electrons are passed directly to oxygen, causing cells to explode
C. Alcohol would build up in the cells
D. NADH supplies would be exhasted, and ATP synthesis would cease.
E. * No proton gradient would be produced, and ATP synthesis would cease.
412.
Cyanide, oligomycin, and 2,4-dinitrophenol (DNP) are inhibitors of mitochondrial
aerobic phosphorylation. Which of the following statements correctly describes the mode
of action of the three inhibitors?
A. Cyanide and 2,4-dinitrophenol inhibit the respiratory chain, and oligomycin
inhibits the synthesis of ATP.
B. * Cyanide inhibits the respiratory chain, whereas oligomycin and 2,4dinitrophenol inhibit the synthesis of ATP.
C. Cyanide, oligomycin, and 2,4-dinitrophenol compete with O2 for cytochrome
oxidase (Complex IV).
D. Oligomycin and cyanide inhibit synthesis of ATP; 2,4-dinitrophenol inhibits the
respiratory chain.
E. Oligomycin inhibits the respiratory chain, whereas cyanide and 2,4-dinitrophenol
prevent the synthesis of ATP.
413.
Cytochromes a and a3 together are called :
A. Succinare dehydrogenase
B. Transaminase
C. Acorbatoxidase
D. * Cytochrome c oxidase
E. None of the above
414.
During aerobic respiration, electrons travel downhill from
A. Food-->Krebs Cycle-->ATP--> NAD+
B. * Food-->NADH-->electron transport chain-->oxygen
C. Glucose-->ATP-->oxygen
D. Glucose-->ATP-->electron transport chain-->NADH
E. Food-->glycolysis-->Krebs Cycle-->NADH-->ATP
415.
During ATP synthesis, the three identical b subunits of the F1 complex
A. * Have similar affinities for ADP and ATP
B. Have different affinities for ADP but not for ATP
C. Have different affinities for ATP but not for ADP
D. Have different affinities for ATP and for ADP
E. Do not bind ADP until a proton dissociates
416.
During cell respiration, most ATP is formed as a direct result of the net movement
of
A. Sodium ions diffusion across a membrane
B. Electrons flowing against a gradient
C. Electrons flowing througth a channel
D. * Protons flowing througth a channel
E. Protons flowing against a gradient
417.
During respiration, the substrate is
A.
B.
C.
D.
E.
418.
A.
B.
C.
D.
E.
Reduced
Hydrogenated
Carbonated
* Oxidised
A and D
FMN - prosthetic group of:
Lactatdehydrogenase
* NADH- dehydrogenase
Alcoholdehydrogenase
Creatincinase
Aminotranspherase
For very high force contractions lasting 1-2 seconds, the initial energy source is
419.
from:
A. Glycolysis
B. Creatine phosphorylation
C. Phosphocreatine stores
D. * ATP stores
E. None of the above
420.
How many ways of ATP formation are in the organism?
A. 1
B. * 2
C. 10
D. 3
E. 5
421.
In a fermentation metabolism, the organism produces ATP by
A. More than one of the above
B. * Generation of a proton motive force by transfer of electrons to oxygen.
C. Oxidizing NADH to form the proton motive force.
D. Substrate level phosphorylation.
E. None of the above
422.
In general, the higher the intensity of exercise, the greater the proportional
contribution of:
A. Aerobic energy production
B. * Anaerobic energy production
C. The TCA cycle (Krebs’ cycle) to the production of ATP
D. The electron transfer chain to the production of ATP
E. Fat oxidation
423.
In the chemiosmotic mechanism:
A. * ATP produciton is linked to the proton gradient established by the electron
transport chain.
B. The difference in pH between the intermembrane space and the cytosol drives the
formation of ATP.
C. The flow of H+ through ATP synthases from the matrix to the intermembrane
space drives the phosphorylation of ADP.
D. The energy released by the reduction and subsequent oxidation of components of
the electron transport chain is transferred as a phosphate to ADP.
E. The produciton of water in the matrix by the reduciton of oxygen leads to a net
flow of water out of a mitochondrion.
424.
Living organisms increase in complexity as they grow, resulting in a decrease in
the entropy of an organism. How does this relate to the second law of thermodynamics?
A. * Life obeys the second law of thermodynamics because the decrease in entropy
as the organism grows is balanced by an increase in the entropy of the universe.
B. As a consequence of growing, organisms create more disorder in their
environment than the decrease in entropy associated with their growth
C. Living organisms are able to transform energy into entropy.
D. Living organisms do not obey the second law of thermodynamics, which states
that entropy must increase with time.
E. Living organisms do not follow the laws of thermodynamics.
425.
NADI-reagent include:
A. H2SO4 and ?-naphtol
B. * Para-phenilendiamine and B-naphtol
C. 2,4 - dinitrophenol and C-naphtol
D. Starch and para-phenilendiamine
E. None of the above
426.
Pyridine-linked dehydrogenases require as coenzymes:
A. FAD, FMN
B. * NAD, NADP
C. TPP, TDP
D. Coenzym A
E. THFA
427.
Reactants capable of interacting to form products in a chemical reaction must first
overcome a thermodynamic barrier known as the reaction's
A. Entropy.
B. Activation energy.
C. Endothermic level.
D. * Free-energy content.
E. Heat content.
428.
Several inhibitors block electron transport in the span between NADH and
ubiquinone, except:
A. Rotenone
B. Amytal
C. Piericidin
D. * Valinomicin
E. None of the above
429.
Substrates for respiratory chain are formed in:
A. Cytoplasm
B. Glycolysis
C. * Krebs cycle
D. Endoplasmic reticulum
E. Gluconeogenesis
430.
The _______ is a unit of chemical energy
A. Grams
B. Volts
C. * Joules/mol
D. Kilocalorie
E. More than one of the above
431.
The 1-st reaction of substrate-level phosphorylation takes place in the
mitochondria matrix and is located in:
A. * Respiratory chain
B. Decarboxilation of pyruvat
C. Gluconeogenesis
D. Krebs cycle
E. Oxidation of fatty acids
432.
The amount of energy required to bring all molecules to a reactive state prior to a
chemical reaction is called the reaction's _____________.
A. Van der Waal's energy
B. Go'
C. Free energy of formation
D. * Activation energy
E. More than one of the above is correct
433.
The antibiotic oligomycin serves as:
A. Activator of respiratiry chain
B. The ingibitor of Krebs cycle
C. * The inhibitor of oxidative phosphorylation
D. The ingibitor of substrate-level phosphorylation
E. None of the above
434.
The ATP produced during fermentation is generated by which of the following?
A. The electron transport chain
B. * Substrate-level phosphorilation
C. Krebs cycle
D. Chemiosmosis
E. Citric acid cycle
435.
The cytochromes are localized in the:
A. Cytosol
B. Nucleus
C. * Inner mitochondrial membrane
D. Ribosoms
E. Matrix of mitochondria
436.
The direct energy source that drives ATP synthesis during respiratory oxidative
phosphorylation is
A. Oxidation of glucose to CO2 and water
B. The thermodynamically favorable flow of electrons from NADH to the
mitochondrial electron transport carriers
C. The final transfer of electrons to oxygen
D. * The difference in H+ concentration on opposite sides of the inner mitochondrial
membrane
E. Thermodynamically favorable transfer of phosphate molecules (from glycolysis
and Krebs cycle intermediates) to ADP
437.
The electrons released by FADH2 during its oxidation to FAD by the electron
transport system finally end up as part of this molecule:
A. Glucose
B. * Water
C. Carbon dioxide
D. ATP
E. CO
438.
The immediate energy source that drives ATP synthesis by ATP synthase during
oxidative phosphorylation is :
A. The flow of electrons down the electron transport chain.
B. * The H+ concentration gradient across the inner mitochondrial membrane.
C. The oxidation of glucose and other organic compounds.
D. The transfer of phosphate to ADP.
E. The affinity of oxygen for electrons.
439.
the inner mitochondrial membrane.
A. The concentration of reduced coenzymes outside the mitochondrial
B. The energy difference between reduced carbon atoms and oxidized
C. * The concentration difference of hydrogen ions between the two sides of
D. The hydrolylsis of ATP to form ADP and Pi.
E. More than one of the above.
440.
The iron-sulfur proteins appear to function as electron carriers by undergoing
reversible :
A. Cu (I) to Cu (II) transitions
B. Na (I) to Na (II) transitions
C. Mg (I) to Mg (II) transitions
D. * Fe(II)-Fe(III) transitions.
E. None of the above
441.
The major reason that glycolysis is not as energy productive as respiration is that:
A. * NAD+ is regenerated by alcohol or lactate production, without the high-energy
electrons passing through the electron transport chain.
B. It is the pathway common to fermentation and respiration.
C. It does not take place in a specialized membrane bound organelle.
D. Pyruvate still contains much of the energy from glucose.
E. Substrate level phosphorylation is not as energy efficient as oxidative
phosphorylation.
442.
The metabolic function of fermentation is to:
A. Oxidize NADH to NAD+ so that glycolysis can continue in the absense of
oxygen.
B. Reduce NADH so that more ATP can be produced by the electron transport chain
C. Produce lactate during aerobic exercises
D. Oxidize pyruvate, thus releasing more energy.
E. * Make beer
443.
The metal ion that acts as an electron carrier in the cytochromes in the electron
transport chain is
A. Magnesium
B. Chromium
C. * Iron
D. Cobalt
E. Hydrogen
444.
The most common substrate of respiration is _________.
A. Amino acids
B. Fats
C. * Glucose
D. Sucrose
E. Vitamins
445.
The prototype of ionophores is the antibiotic:
A. Oligomicin
B. * Valinomycin
C. Antimicin
D. Piericidin
E. None of the above
446.
The terminal cytochrome of mitochondrial respiration include tightly bound:
A. Na
B. P
C. * Cu
D. CI
E. Mg
447.
There are four types of electron-transferring enzymes, except:
A. Pyridine-linked dehydrogenases
B.
C.
D.
E.
Flavin-linked dehydrogenases
Iron-sulfur proteins
* Retinol-isomerase
Cytochromes
448.
Ways of ATP formation in the organism:
A. Hydrolysis of simple proteins and separation of amino acid
B. Salting-out and denaturation of proteins
C. * Oxidative phosphorylation and substrate-level phosphorylation.
D. Decarboxilation of pyruvat and gluconeogenesis
E. All of above
449.
What is the change in free energy of a system at chemical equilibrium?
A. * No net change
B. Slightly increasing
C. Slightly decreasing
D. Greatly increasing
E. Greatly decreasing
450.
Where is ATP formed during oxidative phosphorylation ?
A. In the mitochondria
B. In the cytoplasm
C. In the respiratory chain
D. On the cytochromes
E. * On the ATP-synthase, which is located in the mitochondrial matrix and
penetrate inner membrane
451.
Which of the following class of vitamins are found in NAD, FAD, and FMN?
A. Water soluble
B. Coenzymes
C. * B vitamins
D. Antioxidants
E. More than one of the above.
452.
Which of the following coenzymes would have to be continually present in the
cell in order for the oxidative reactions of glycolysis to continue?
A. FADH2
B. * NADH
C. ATP
D. NAD+
E. All of the above
453.
Which of the following describe(s) some aspect of metabolism?
A. Breakdown of macromolecules
B. Synthesis of macromolecules
C. Control of enzyme activity
D. * A and B only
E. A, B, and C
454.
Which of the following forms of energy is least available to accomplish cellular
work?
A. Electrical energy
B. * Mechanical energy
C. Light energy
D. Thermal energy (heat)
E. Potential energy
455.
Which of the following is (are) true for anabolic pathways?
A. They do not depend on enzymes.
B. They are highly regulated sequences of chemical reactions.
C. * They consume energy to build up polymers from monomers.
D. They release energy as they degrade polymers to monomers.
E. Both B and C
456.
Which of the following is not a significant biological oxidizing agent?
A. Fe3+
B. NAD+
C. FAD
D. Ubiquinone (a.k.a. CoQ)
E. * O2
457.
Which of the following produces ATP, reduced coenzymes as high energy
molecules and CO2 as its major chemical waste product.
A. Electron transport
B. Glycolysis
C. beta – oxidation or fatty acids
D. * Citric acid cycle
E. Oxidative phosphorylation
458.
Which of the following reaction is incorrectly paired with its location?
A. * ATP synthesis>inner membrane of the mitochondrion, matrix, and cytosol.
B. Fermentation>cell cytosol
C. Glycolysis>cell cytosol
D. Substrate-level phosphorylation>cytosol and matrix
E. Citric acid cycle>cristae of mitochondrion
459.
Which of the following statements is true about the role of O2 in electron
transport?
A. * As the final electron acceptor, O2 gets reduced and becomes a part of a water
molecule.
B. As the final electron donator, O2 gets oxidized and becomes a part of an ATP
molecule.
C. As the final electron acceptor, O2 gets reduced and becomes a part of an ATP
molecule.
D. As the final electron donator , O2 gets oxidized and becomes a part of a NADH
molecule.
E. None of the above.
460.
Which process of cell respiration is most closely associated with intracellular
membranes?
A. Fermentation
B. The Krebs cycle
C. Glycolysis
D. Substrate-level phosphorilation
E. * Oxidative phosphorilation
461.
Which term most precisely describes the cellular process of breaking down large
molecules into smaller ones?
A. Dehydration
B. Catalysis
C. Anabolism
D. * Catabolism
E. Metabolism
462.
Why is ATP an important molecule in metabolism?
A. * It provides energy coupling between exergonic and endergonic reactions.
B. Its hydrolysis provides an input of free energy for exergonic reactions.
C. Its terminal phosphate group contains a strong covalent bond that when
hydrolyzed releases free energy.
D. A and B only
E. A, B and C
463.
A 2-years-old child has symptoms of galactosemia. Among them the following is
marked:
A. Dermatitis
B. Dementia
C. Keratomalacia
D. * Cataract
E. Xerophtalmia
464.
A 46 years old woman appealed to the doctor with complaints about pain in the
epigastrium after the fatty meal. Doctor suspected acute pancreatitis. Content of which
from the transferred substances in blood increased at this pathology?
A. Glucose
B. Aspartate amino transferase
C. Alanine amino transferase
D. * Amylase
E. Calcium
465.
A child after the mixed meal which contains sucrose suffered from vomiting and
cramps. After the exception of sugar from a diet, these symptoms disappeared. Probably,
that patient suffers from:
A. Galactosemia
B. Undigestion of lactose
C. Essential pentoseuria
D. Glycogenosis
E. * Undigestion of fructose
466.
A child was delivered to a reanimation with such symptoms: vomit, diarrhea,
abnormal physical and mental development, cataract. Laboratory test showed
galactosemia. The deficiency of what enzyme does take place?
A. Galactokinase
B. UDP glucose-4-epimerase
C. * Hexose-1-phosphate-uridiltransferase
D. UDP- glucose –pyrophosphorilase
E. Glucose-6-phosphate dehydrogenase.
467.
A deficiency in thiamin causes the disease beriberi. Which might you expect to
have a higher than normal blood concentration in an individual with this condition?
A. isocitrate
B. * pyruvate
C. oxaloacetate
D. acetyl CoA
E. malate
468.
A new-born child has diarrhea, vomiting and cataract. Disorder of synthesis of
what enzyme causes this disease?
A. * Galactose – 1 – phosphate uridyl transpherase
B. Glucose - 6 phosphatase
C. Hexokinase
D. Glycogen synthase
E. Glucose phosphate isomerase
469.
A new-born child has diarrhea, vomiting and cataract. Disorder of synthesis of
what enzyme caused this disease?
A. * Galactose – 1 – phosphate uridyl transpherase
B. Glucose - 6 phosphatase
C. Hexokinase
D. Glycogen synthase
E. Glucose phosphate isomerase
470.
A newborn suffers from the fatty degeneration of liver, takes place a galactosuria
and amino aciduria, increased level of total bilirubin in blood. What matter is it necessary
to exclude from the diet of child?
A. * Lactose
B. Fatty acids
C. Phenylalanine
D. Cholesterol
E. Saccharose
471.
A patient complains about acute stomach-ache, nausea, vomit. Diastase activity is
800 grammes/l• hour What diagnosis is the most possible?
A. Acute cholecystitis
B. * Acute pancreatitis
C. Ulcer of stomach
D. Acute appendicitis
E. Enterocolitis
472.
A patient has metabolic acidosis. How will it change activity of intracellular
enzymes?
A. Activity of intracellular enzymes do not change substantially.
B. Activity of mitochondrial enzymes increased, activity of lysosomal enzymes
inhibited, which is accompanied the decline of catalytic processes.
C. * Activity of mitochondrial enzymes is low, activity of lysosomal enzymes, which
will result in strengthening of catalytic processes, is increased.
D. Total inhibition of all of tissue enzymes.
E. Total activating of all of tissue enzymes.
473.
A patient has metabolic acidosis. How will it change activity of intracellular
enzymes?
A. Activity of intracellular enzymes does not change substantially.
B. Activity of mitochondrial enzymes increases, activity of lysosomal enzymes
inhibits, which is accompanied the decline of catalytic processes.
C. * Activity of mitochondrial enzymes is low, activity of lysosomal enzymes, which
will result in strengthening of catalytic processes, is increased.
D. Total inhibition of all of tissue enzymes.
E. Total activating of all of tissue enzymes.
474.
A patient is found to be deficient in the enzyme galactose 1-phosphate
uridylyltransferase. Specifically due to this deficiency what might a doctor recommend?
A. avoid all strenuous exercise
B. eat a fat-free diet
C. increase intake of vitamin C
D. * avoid ingestion of milk and milk products
E. increase intake of milk
475.
A patient is found to be deficient in the enzyme galactose 1-phosphate
uridylyltransferase. Specifically due to this deficiency what might a doctor recommend?
A. avoid all strenuous exercise
B. eat a fat-free diet
C. increase intake of vitamin C
D. * avoid ingestion of milk and milk products
E. all of the above.
476.
A patient was diagnosed with beri-beri disease. Activity of which enzyme is
inhibited in an organism of the patient?
A. Fumarase
B.
C.
D.
E.
Citrate synthase
Malate dehydrogenase
Succinate dehydrogenase
* Pyruvate dehydrogenase
477.
A patient with pellagra (a result of vitamin of PP luck) has low activity of the
followings enzymes of glycolysis:
A. Glucokinase and enolase
B. * Glyceraldehyde 3-Phosphate dehydrogenase and lactate dehydrogenase
C. Aldolase and pyruvatekinase
D. Lactate dehydrogenase and hexokinase
E. Pyruvate dehydrogenase and aldolase
478.
After hard physical work during rest there are stimulation some metabolic ways of
carbohydrates, except:
A. Glycogenes
B. Gluconeogenesis from lactat
C. Gluconeogenesis from glycerin
D. * Glycolysis, Krebs cycle
E. Gluconeogenesis from amino acids
479.
As a result of worker's exhausting muscle activity the strongly decreased buffer
capacity of blood occurs. Accumulation of which substance in the blood explains this
event?
A. 3-phosphoglycerate
B. pyruvate
C. 1,3-biphosphoglycerate
D. * lactate
E. E-ketoglutarate
480.
At entering in organism big amount of toxic substances glucose-6-phosphate in a
liver including in:
A. Glycolysis
B. Glycogenogenesis
C. Glycolysis, Krebs cycle
D. * Pentosophosphate cycle
E. Gluconeogenesis
481.
At the short starvation after the consumption of carbohydrate meal, hexoses in a
liver transform into glucose-6-phosphate, which can be used in all pathways, except:
A. * Gluconeogenesis
B. Pentosophosphate cycle
C. Synthesis of glycogen
D. Glycolysis
E. Synthesis of fatty acids
482.
By the ambulane car a patient was delivered to the hospital, who became
unconscious in the street. Biochemical blood analysis showed: ketone bodies
concentration 6,8 mmol/l, urea concentration 7,5 mmol/l, increased concentration of Cprotein, amount of calcium 2,2 mmol/l, blood glucose 2,5 mmol/l. What is the possible
reason for getting unconscious?
A. * hypoglycemia
B. ammonia formation malfunction
C. hypocalcemia
D. acetonemia
E. hyperthyroidism
483.
Concentration of pyruvic acid and lactic acid in blood of a patient with
sympthoms of beri beriis is increased due to deficiency of the vitamin:
A.
B.
C.
D.
E.
* Thiamin
Riboflavin
Niacin
Pantothenic acid
Ascorbic acid
484.
During wet beriberi, peripheral vessels dilate and heart muscles loose their
contractility. Some people think this is a result of a failure of the TCA cycle. Evidence
for this is an increase in the
A. Rate of production of succinate
B. Rate of production of NADH
C. * Concentration of alpha-ketoglutarate and pyruvate
D. Production of ATP
E. Production of FADH2
485.
For diagnosis of patients with an innate and early cataract, it is necessary to
inspect them on a presence of:
A. Fructosemia
B. Hyperuricemia
C. Pentosemia
D. Hyperlactemia
E. * Galactosemia
486.
If a patient with the deficiency of lactase uses milk and milk products, such
symptom can be observed as:
A. An increase of concentration of glucose is in blood
B. Appearance of galactose in urine
C. An increase of concentration of galactose in blood
D. * Diarrhea
E. Dermatitis
487.
In blood and urine of a patient it was takes place increase value of pyruvic and ?ketoglutaric acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
488.
In blood and urine of a patient it was takes place increase value of pyruvic and
ketoglutaric acids. The deficiency of which coenzyme causes these changes?
A. Pyridoxal phosphate
B. * Thiamin pyrophosphate
C. Flavin mononucleotide
D. Biotin
E. Ubiqinon
489.
In some Diabetic patients, glucose increases disproportionately and is
unresponsive to an insulin challenge; under these conditions, how would one's liver
normally respond?
A. Phosphorylating glucose for entry into the glycolytic pathway
B. Saturating glucokinase with glucose
C. Phosphorylating glucose for entry into the glycogen synthesis pathways
D. a and b only
E. * a and c only
490.
In the organism of patient with inherited galactosemia accumulate galactose-1phosphate, a free galactose and a such alcohol - toxic product of its reduction as:
A. Glycerol
B.
C.
D.
E.
* Dulcitol
Inositol
Retinol
Ethanol
491.
Patient has sympthoms of beri beri (lack of B1). B1 formes coenzyme TPP which
is involved in:
A. * Oxidative decarboxylation
B. Hydroxylation
C. Transamination
D. Carboxylation
E. Oxidation
492.
Patient has sympthoms of beri beri. Both Wernicke’s disease and beri beri can be
reversed by administrating:
A. Retinol
B. * Thiamin
C. Pyridoxine
D. Vitamin B12
E. Cholecalciferol
493.
Patient with atherosclerosis suffers from severe ischemic heart disease. Which
process will prevail in the cardiac muscle?
A. * anaerobic glucose decomposition
B. ketone bodies synthesis
C. glycerin oxidation
D. aerobic glucose decomposition
E. ketone bodies oxidation
494.
Patients which suffer from inherited undigestion of fructose must not use such
disaccharide as:
A. Cellobiose
B. Lactose
C. Maltose
D. * Sucrose
E. All of the above
495.
People, who for a long time were in the condition of hypodynamia after intensive
physical activity have strong muscle pain. What is the most probable reason of this
condition?
A. * increased concentration of lactic acid in the muscles
B. increased decomposition of muscle proteins
C. concentration of creatine in the muscles
D. increased muscle stimulation
E. increase of ADP in the muscles
496.
Teturam which is the inhibitor of aldehyde dehydrogenase used in medical
practice for the prophylaxis of alcoholism. An increase in blood of what metabolite
causes disgust of an alcohol?
A. malonic aldehyde
B. Ethanol
C. * Acetaldehyde
D. Proponic aldehyde
E. Methanol
497.
The accumulation of pyruvate in blood, decrease of activity of red blood cells
transketolase takes place of a 36 years patient, which suffers with chronic alcoholism.
Insufficiency of coenzyme form of which vitamin causes such changes?
A. * Thiamine diphosphate
B.
C.
D.
E.
Carboxybiotin
Metylcobalamin
Phosphopyridoxal
Tetrahydrofolate
498.
The inherited genetic defects result in violation of synthesis of some enzymes in
the human organism. The defect of which enzyme results in disorders of splitting of
lactose:
A. * Lactase
B. Maltase
C. Sucrase
D. Amylase
E. Peptidase
499.
The patient complains for undue fatiguability after working day, constant thirst. A
doctor suspected diabetes mellitus. Choose the blood plasma glucose concentration,
which proves the diagnosis:
A. * 8,5 mmol/l
B. 2 mmol/l
C. 4,5 mmol/l
D. 5 mmol/l
E. 3,3 mmol/l
500.
The patient has inhibited oxidative pyruvate decarboxylation. How many ATP
molecules less the organism will receive at the oxidation of a single glucose molecule?
A. * 30 ATP molecules per each glucose molecule
B. 36 ATP molecules per each glucose molecule
C. 2 ATP molecules per each glucose molecule
D. there will be no ATP deficiency because less synthesis is compensated by
intensive fat decomposition
E. 12 ATP molecules per each glucose molecule
501.
The rate at which pyruvate from glycolysis is used by the TCA cycle to produce
energy is regulated by pyruvate dehydrogenase. During muscle contraction, this enzyme
is
A. Inhibited by increases in the calcium concentration.
B. Activated by increased in acetyl CoA
C. Activated by increases in NADH
D. * Activated by increases in ADP
E. Inhibited by increases in AMP
502.
? Vomiting, diarrhea after consuming milk, enlargement of the liver, jaundice,
cirrhosis,cataracts, retardation of the mental development, elevated blood-galactose level,
absence of the galactose 1-phosphate uridyl transferase in red blood cells are the
symptoms of:
A. lactose intolerance
B. hypolactasia
C. * galactosemia
D. all of the above
E. diabetes mellitus
503.
Vomiting, diarrhea after consuming milk, enlargement of the liver, jaundice,
cirrhosis,cataracts, retardation of the mental development, elevated blood-galactose level,
absence of the galactose 1-phosphate uridyl transferase in red blood cells are the
symptoms of:
A. lactose intolerance;
B. hypolactasia;
C. * galactosemia;
D. all of the above.
E. diabetes mellitus
504.
Which metabolic ways transformation of glucose-6-phosphate will prevail in a
liver at the condition activation of biosynthetic processes?
A. Gluconeogenesis
B. Glycolisis
C. Transformation of glucose-6-phosphate on free glucose and phosphate
D. * Pentosophosphate cycle
E. Glycogenesis
505.
Yeast will normally convert pyruvate to ethanol. Why is this better for the yeast
than a conversion to lactate?
A. Conversion to ethanol releases more NAD+ per mole than the conversion to
lactate.
B. The carbon atoms are more oxidized in ethanol than in lactate.
C. * Ethanol is neutral, but lactate production is accompanied by a sharp decrease in
pH.
D. Ethanol production is not better. Yeast normally produces ethanol and lactate in
equilmolar amounts.
E. All of the above
506.
42 years old man for dinner ate a big portion of spaghetti, a piece of cake, had a
glass of sweet tea. What hepatocyte enzyme activity is activated mostly ?
A. * Hexokinase
B. Glucose-6-phosphatase
C. Glucose-6-phosphatdehydrogenase
D. Glycogen phosphorylase
E. E-galactosidase
507.
8 month old child has vomiting and diarrhea after having fruit juice. There is an
increased level of fructose in the blood. This is conneceted with the lack of the enzyme:
A. * Fructokinase
B. Ketose-1-phosphate aldolase
C. Isomerase
D. Triosephosphate isomerase
E. Phosphorylase
508.
A 62 yaears old woman with diabetes mellitus has cataract (lenticular opacity) by
. What is the reason?
A. Ketogenesis
B. Lipolysis
C. Protein proteolysis
D. * Protein glycosylation
E. . Gluconeogenesis
509.
A doctor was visited by a patient with complains on constant thirst.
Hyperglycemia, polyuria and increased amount of 17-ketosteroid in the blood were
found. What disease is the most possible?
A. Insulin-dependent diabetes
B. * Steroid diabetes
C. Myxedema
D. I type glycogenolysis
E. Addison's disease
510.
A key element in the regulation of glycogen metabolism is the phosphorylation by
protein kinase A of phosphorylase kinase which ______ (activates, inactivates) and the
phosphorylation of glycogen synthase which _______ (activates, inactivates).
A. Activates; activates
B. * Activates; inactivates
C. Inactivates; inactivates
D. Inactivates; activates
511.
A patient has developed general adiposity and atherosclerosis as a result of
everyday usage of:
A. * 600 g carbohydrates
B. 150 g protein
C. 50 g vegetable oil
D. 100 g fats
E. 10 mg vitamin A
512.
A patient is found to be deficient in the enzyme galactose 1-phosphate
uridylyltransferase. Specifically due to this deficiency what might a doctor recommend?
A. Avoid all strenuous exercise
B. Eat a fat-free diet
C. Increase intake of vitamin C
D. * Avoid ingestion of milk and milk products
E. Increase intake of vitamin B1
513.
A woman of 58 years is hard condition. Consciousness is blear, skin is dry, eyes
are sunken, cyanosis, the smell of rotting apples from the mouth. Blood glucose - 15,1
mmol/l, urine glucose 3,5%. What is the most real reason for such condition?
A. Uremic coma
B. Hypovalemic coma
C. Anaphylactic shock
D. * Hyperglycemic coma
E. Hypoglycemic coma
514.
According to the classic glucose-fatty acid cycle, which two metabolites are
predicted to increase in skeletal muscle when fat becomes the major substrate oxidized?
A. ADP, AMP
B. * Acetyl CoA, citrate
C. Pyruvate dehydrogenase, phosphofructokinase
D. Glycogen, triglyceride
E. All of the above
515.
All are true for ?-amylase EXCEPT:
A. Catalyzes hydrolysis of ? (1 4) linkages in starch.
B. Is an important component of saliva and pancreatic juice.
C. * Catalyzes hydrolysis of ? (1 6) linkages in amylopectin.
D. Catalyzes hydrolysis of ? (1 4) linkages in glycogen.
E. Activity is reduced in highly branched regions of polysaccharides and stops four
residues from any branch point.
516.
All enzymes of gluconeogenesis are located in:
A. * Cytoplasm
B. Matrix of mitochondria
C. Inner membrane of mitochondria
D. None of the above.
E. Nucleus
517.
An enzyme used in both glycolysis and gluconeogenesis is:
A. * 3-phosphoglycerate kinase.
B. Glucose 6-phosphatase.
C. Hexokinase.
D. Phosphofructokinase-1.
E. Pyruvate kinase.
518.
At the subcellular level, where do the reactions of gluconeogenesis occur?
A.
B.
C.
D.
E.
Al in the cytosol
Al in the mitochondria
In the cytosol and the endoplasmic reticulum
* In the cytosol and the mitochondra
In the plasma membrane
519.
Biochemical blood analysis of a 1-year old child showed hypoglycemia. After
injection of epinephrine hyperglycemia did not appear. During clinical inspection were
observed growth inhibition, spasms, increase of liver and kidney. Lack or excess of
which enzyme causes such pathology?
A. Lack of muscle phosphorylase
B. * Excess of glucose-6-phosphatase
C. Lack of liver phosphorylase
D. Excess of muscle phosphorylase
E. Lack of glucokinase
520.
Biochemical blood analysis of a 32 years old patient, who starved for 3 days,
showed that the amount of glucose is normal. What process provides the normal glucose
level in the blood of a healthy man after 3-4 days of starvation?
A. * Gluconeogenesis
B. Glycolysis
C. Pentose-phosphate pathway
D. Krebs cycle
E. Glycogen synthesis
521.
Bypassed reactions in gluconeogenesis are:
A. * Conversion of pyruvate to phosphoenolpyruvate; conversion of fructose 1,6bisphosphate to fructose 6-phosphate; conversion of glucose 6-phosphate to
glucose;
B. Conversion of pyruvate to phosphoenolpyruvate; conversion 2-phosphoglicerate
to 3-phosphoglicerate; conversion of fructose 6-phosphate to glucose 6phosphate;
C. Conversion of 2-phosphoglicerate to 3-phosphoglicerate; conversion of fructose
6-phosphate to glucose 6-phosphate; conversion of glucose 6-phosphate to
glucose;
D. Conversion of 3-phosphoglicerate to 1,3-biphosphoglycerate; conversion of
fructose 1,6-bisphosphate to fructose 6-phosphate; conversion of glucose 6phosphate to glucose.
E. None of the above
522.
Concerning some general principles of glucose metabolism:
A. * Gluconeogenesis is stimulated when plasma glucose is low.
B. Gluconeogenesis is the formation of glucose from glycogen.
C. Glycogenesis is stimulated when cellular ATP reserves are low.
D. Glucose may be synthesized from fatty acids.
E. Glucose may be synthesized from vitamins.
523.
During fasting, what role does gluconeogenesis play?
A. Aids in the release of glucose from stored glycogen in the liver.
B. * Uses protein (amino acids) to restore blood glucose levels.
C. Produces products that slow the oxidation of pyruvate.
D. Helps transport glucose across the blood-brain barrier to maintain brain glucose
levels.
E. None of the above
524.
During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate
dehydrogenase reaction in skeletal muscle must be reoxidized to NAD+ if glycolysis is to
continue. The most important reaction involved in the reoxidation of NADH is:
A.
B.
C.
D.
E.
Dihydroxyacetone phosphate > glycerol 3-phosphate
Glucose 6-phosphate > fructose 6-phosphate
Isocitrate > ?-ketoglutarate
Oxaloacetate > malate
* Pyruvate > lactate
525.
Each following line is a statement about Glycolysis.
A. n enzyme which catalyses a reaction consuming ATP
B. * n enzyme which catalyses a reaction generating ATP.
C. n enzyme which has an allosteric ATP site
D. An enzyme which catalyses a reaction fixing Pi.
E. An enzyme which catalyses a reaction generating NADH.
526.
Each of the following is a statement about energy metabolism. If it can be applied
to carbohydrates:
A. Can provide energy to flowering plants.
B. Can provide energy to some germinating seeds.
C. * Is the usual source of energy for brain.
D. Is the usual source of energy for skeletal muscle.
E. Can provide energy to skeletal muscle.
527.
Each of the following is the name of an enzyme found in the cytosol of
hepatocytes, which are capable of both glycolysis and gluconeogenesis.
A. Ppyruvate kinase
B. * Fructose 1,6-bisphosphatase
C. Phosphoenolpyruvate carboxykinase
D. Hexokinase
E. Phosphofructokinase 1
528.
For each molecule of glucose converted to pyruvate in the glycolytic pathway ___
molecules of ATP are used initially (Stage I) and ____ molecules of ATP are produced
(Stage II) for an overall yield of ___ molecules of ATP/glucose. The "ATP math" is:
A. * -2 + 4 = 2
B. -1 + 4 = 3
C. -2 + 5 = 3
D. -1 + 2 = 1
E. 2 + 2 = 4
529.
?For long-term storage, glucose is converted to ______ , while for short-term
storage, glucose is converted to
A. Fat, glycogen
B. * Glycogen, ketone bodies
C. Fat, pyruvic acid
D. Glycogen, protein
E. Pyruvic acid, fat
530.
For oxaloacetate to be used as a precursor in gluconeogenesis, it must first be
transported across the inner mitochondrial membrane in the form of:
A. * Malate.
B. Oxaloacetate.
C. Aspartate
D. Citrate
E. Both A and C are correct.
531.
Fructose 2,6-bisphosphate (F-2,6-BP) is a:
A. Activator of phosphofructokinase 1;
B. Inhibitor of phosphofructokinase 1;
C. Activator of hexokinase;
D. * Activator of pyruvate-kinase.
E. All of the above.
532.
Galactosemia is a genetic error of metabolism associated with:
A. Deficiency of galactokinase.
B. Deficiency of UDP-glucose.
C. * Deficiency of UDP-glucose: galactose 1-phosphate uridylyltransferase.
D. Excessive ingestion of galactose.
E. Inability to digest lactose.
533.
Gluconeogenesis is
A. The result of ?-amylase activity
B. The formation of glycogen
C. The formation of starches
D. * The formation of glucose from noncarbohydrates
E. The formation of glucose from other carbohydrates
534.
Gluconeogenesis shares some, but not all, enzymes with the glycolytic pathway. It
would appear to be more efficient if both pathways used all of the same enzymes since
the pathways are essentially the reverses of each other. Why don't both pathways use all
of the same enzymes?
A. The reactions where enzymes differ occur in different parts of the cell for
glycolysis versus gluconeogenesis.
B. Enzymes can catalyze a reaction only in one direction, so naturally the two
pathways have some enzymes that differ.
C. In tissues where gluconeogenesis occurs, the glycolytic enzymes are present at
extremely low concentrations.
D. * Three of the reaction steps in gluconeogenesis would have prohibitively large,
positive free energies if they used glycolytic enzymes for their catalysis.
E. Only A
535.
Gluconeogenesis uses the same enzymatic reaction of glycolysis except for
A. Pyruvate kinase
B. * 4 irreversible reactions in glycolysis
C. 3 irreversible reactions in glycolysis
D. 2 irreversible reactions in glycolysis
E. 1 irreversible reactions in glycolysis
536.
Glucose 1-phosphate formed by glycogenolysis is converted to glucose 6
phosphate by phosphoglucomutase because
A. Glucose 6-phosphate is more stable
B. Glucose 6-phosphate is converted to free glucose
C. * Glucose 6-phosphate is an intermediate in several pathways, including
glycolysis
D. Glucose 6-phosphate can be transported to the liver
E. All of the above
537.
Glucose can be produced by gluconeogenesis by all the sources below except:
A. Glycerol
B. Amino acids
C. * Fatty acids
D. Lactate
E. Pyruvat
538.
Glucose labeled with 14C in C-1 and C-6 gives rise in glycolysis to pyruvate
labeled in:
A. A and C.
B. All three carbons.
C. Its carbonyl carbon.
D. Its carboxyl carbon.
E. Its methyl carbon.
539.
Glucose-6-phosphate dehydrogenase deficiency is the ______________ which is
characterized by ___________________________________.
A. Genetically determined disease; the absence of receptors to LDL on cells and
prominent atherosclerosis;
B. Diet-induced disease; the deficit of thiamin in the organism and neurological and
cardiac symptoms;
C. * Genetically determined disease; the low level of reduced glutathione in
erythrocytes and increased susceptibility of erythrocytes to hemolysis;
D. Disease induced by environmental factors; the high level of oxidized glutathione
in the red blood cell and increased resistance of erythrocytes to hemolysis.
E. None of the above.
540.
Glycogen phosphorylase is ________ (more, less) active when phosphorylated
and it is __________ (activated, inhibited) by glucose 6-phosphate.
A. More; activated
B. Less; activated
C. * More; inhibited
D. Less; inhibited
E. None of the above
541.
Glycogen synthesis takes place in the following oragans:
A. Brain and muscles
B. * Liver and muscles
C. Liver and kidney
D. Liver and pancreas
E. All of the above
542.
Glycolysis is defined as:
A. Aerobic process in which glucose is transformed to CO2 and H2O;
B. Anaerobic process in which glucose is transformed to pyruvate;
C. Anaerobic process in which glucose is converted to pentoses and NADPH is
produced;
D. Aerobic process in which glucose is converted to glycogen.
E. * Anaerobic process in which glucose is transformed to lactate;
543.
Glycolysis is the name given to a metabolic pathway occurring in many different
cell types. It consists of 11 enzymatic steps that convert glucose to lactic acid. Glycolysis
is an example of:
A. Aerobic metabolism.
B. Anabolic metabolism.
C. A net reductive process.
D. * Fermentation.
E. Oxidative phosphorylation.
544.
I type glycogenosis (hepatorenal glycogenosis) is connected with the deficit of
glucose-6-phosphatase in the liver, kidney and intestines mucous tunic. Which of the
mentioned symptoms is not characteristic for this disease?
A. Hyperglycemia
B. Hypoglycemia
C. * Hyperazotemia
D. Lipemia
E. Ketonuria
545.
If glucose labeled with 14C at C-1 (the aldehyde carbon) were metabolized in the
liver, the first radioactive pyruvate formed would be labeled in:
A. All three carbons.
B. Both A and C.
C. Its carbonyl carbon.
D. Its carboxyl carbon.
E. * Its methyl carbon.
546.
If glucose labeled with 14C in C-1 were fed to yeast carrying out the ethanol
fermentation, where would the 14C label be in the products?
A. In C-1 of ethanol and CO2
B. In C-1 of ethanol only
C. * In C-2 (methyl group) of ethanol only
D. In C-2 of ethanol and CO2
E. In CO2 only
547.
In an anaerobic muscle preparation, lactate formed from glucose labeled in C-3
and C-4 would be labeled in:
A. All three carbon atoms
B. Only the carbon atom carrying the OH
C. * Only the carboxyl carbon atom
D. Only the methyl carbon atom
E. The methyl and carboxyl carbon atoms
548.
In glycolysis, fructose 1,6-bisphosphate is converted to two products with a
standard free-energy change (?G'°) of 23.8 kJ/mol. Under what conditions (encountered
in a normal cell) will the free-energy change (?G) be negative, enabling the reaction to
proceed to the right?
A. If the concentrations of the two products are high relative to that of fructose 1,6bisphosphate.
B. The reaction will not go to the right spontaneously under any conditions because
the ?G'° is positive.
C. Under standard conditions, enough energy is released to drive the reaction to the
right.
D. * When there is a high concentration of fructose 1,6-bisphosphate relative to the
concentration of products.
E. When there is a high concentration of products relative to the concentration of
fructose 1,6-bisphosphate.
549.
In humans, gluconeogenesis:
A. * Can result in the conversion of protein into blood glucose.
B. Helps to reduce blood glucose after a carbohydrate-rich meal.
C. Is activated by the hormone insulin
D. Is essential in the conversion of fatty acids to glucose.
E. Requires the enzyme hexokinase.
550.
In some Diabetic patients, glucose increases disproportionately and is
unresponsive to an insulin challenge; under these conditions, how would one's liver
normally respond?
A. Phosphorylating glucose for entry into the glycolytic pathway
B. Saturating glucokinase with glucose
C. Phosphorylating glucose for entry into the glycogen synthesis pathways
D. A and b only
E. * A and c only
551.
In the alcoholic fermentation of glucose by yeast, thiamine pyrophosphate is a
coenzyme required by:
A. Aldolase.
B. Hexokinase.
C. Lactate dehydrogenase.
D. * Pyruvate decarboxylase.
E. Transaldolase.
552.
In the blood of the patient the amount of glucose on the empty stomach is 5,6
mmol/l, after an hour after sugary loading – 13,8 mmol/l, after two hours – 9,2 mmol/l.
Such figures are typical for:
A. Healthy man
B. Patient with thyrotoxicosis
C. * Patient with hidden form of diabetes mellitus
D. Patient with Cushing's syndrome
E. Patient with acromegaly
553.
In the Cori cycle, gluconeogenesis occurs in _____ and glycolysis in ______.
A. * Liver; muscle
B. Liver; liver
C. Muscle; muscle
D. Muscle; liver
E. Heart; brain
554.
Inorganic fluoride inhibits enolase. In an anaerobic system that is metabolizing
glucose as a substrate, which of the following compounds would you expect to increase
in concentration following the addition of fluoride?
A. * 2-phosphoglycerate
B. Glucose
C. Glyoxylate
D. Phosphoenolpyruvate
E. Pyruvate
555.
Lactate is formed from pyruvate in an _____ organism in ______ conditions.
A. Yeast; aerobic;
B. Animal; aerobic;
C. Fungi; aerobic;
D. * Animal; anaerobic.
E. Yeast; aerobic.
556.
More ATP is formed from glucose in glycogen than from free glucose, even free
glucose released from glycogen because
A. Limit dextrin contains additional molecules
B. The debranching enzyme releases free glucose
C. * The glucose is already phosphorylated after glycogen phosphorylase action
D. The glucose bypasses glycolysis
E. All of the above
557.
Nervous tissue depends upon glucose for its primary source of energy. However,
these molecules can be used as an alternative source of energy by nervous tissue:
A. * Ketones
B. Steroids
C. Fatty acids
D. Amino acids
E. All of the above
558.
Pentoses, which are formed in pentose-phosphate cycle are used for the following
processes, except:
A. * Glycogen synthesis
B. Coenzyme synthesis
C. Nucleic acid synthesis
D. ATP synthesis
E. Cyclic adenosine monophosphate synthesis
559.
PFK-2 and fructose 2,6-bisphosphatase are two names for the same enzyme. The
name PFK-2 is used for the enzyme's catalysis of the phosphorylation of fructose 6phosphate to fructose 2,6-bisphosphate. The name fructose 2,6-bisphosphatase is used for
its catalysis of the reverse reaction. What is unique about this enzyme that makes it
logical to use both names?
A. It is one of very few enzymes that can catalyze both the forward and reverse
reactions.
B. The enzyme is a monomer when catalyzing the phosphorylation reaction and a
dimer when catalyzing the reverse reaction.
C. The forward and reverse reactions occur in different compartments within the
cell, so a different name is used for each activity.
D. * The enzyme is bifunctional. The forward and reverse reactions are catalyzed by
different sites on the same enzyme.
E. All of the above.
560.
Phosphofructokinase, the major flux-controlling enzyme of glycolysis is
allosterically inhibited by ___ and activated by ___.
A. AMP Pi
B. ADP AMP
C. Сitrate ATP
D. ATP PEP
E. * ATP ADP
561.
Protein kinase A, which stimulates glycogen degradation, is activated directly by
A. Glucagon
B. Insulin
C. Epinephrine
D. * Cyclic AMP
E. Adrenergic receptors
562.
Regarding diabetes mellitus:
A. * Is always the result of a failure of insulin synthesis.
B. Is characterized by a fall in urine output.
C. Is associated with an increase in lipolysis
D. eads to hypoglycemia.
E. None of the above
563.
The anaerobic conversion of 1 mol of glucose to 2 mol of lactate by fermentation
is accompanied by a net gain of:
A. 1 mol of ATP.
B. 1 mol of NADH.
C. * 2 mol of ATP.
D. 2 mol of NADH.
E. None of the above.
564.
The concentration of glucose in the blood of a patient is 4,5 mmol/l, glucose
appears in urine. The possible reason for this condition:
A. Thyroid gland hyperfunctioning
B. Acromegaly
C. Glycogenosis
D. * Kidney disease
E. Stress
565.
The conversion of 1 mol of fructose 1,6-bisphosphate to 2 mol of pyruvate by the
glycolytic pathway results in a net formation of:
A. 1 mol of NAD+ and 2 mol of ATP.
B. 1 mol of NADH and 1 mol of ATP.
C. 2 mol of NAD+ and 4 mol of ATP.
D. 2 mol of NADH and 2 mol of ATP.
E. * 2 mol of NADH and 4 mol of ATP.
566.
The conversion of glycogen to glucose-6-phosphate is the first step in
A.
B.
C.
D.
E.
Glycolysis
Gluconeogenesis
* Glycogenolysis
Glycogenesis
A and C
567.
The enzyme found only in the liver that removes phosphate groups and can, thus,
release free glucose for distribution around the body by the blood is
A. Glycogen synthetase
B. Glucose-6-phosphatase
C. * Glycogen phosphorylase
D. Glucose isomerase
E. only B
568.
The enzyme which the key regulatory step in glycogen biosynthesis is
A. * Glycogen synthase
B. Glycogenin
C. Branching enzyme
D. Phosphoglucomutase
E. UDP-glucose pyrophosphorylase
569.
The family of GluT (glucose transporters) is:
A. * The proteins embedded into the cell membrane and facilitating the glucose
transport across the membrane;
B. The proteins embedded into the cell membrane and inhibiting the glucose
transport across the membrane;
C. The cytoplasmic proteins transporting glucose in the cytoplasm of cell;
D. The proteins of blood plasma transporting glucose via the blood.
E. None of the above.
570.
The initiation of glycogen synthesis (ie the very first glucose residue added )
occurs by transfer of glucose from UDP-glucose to the:
A. * 4-position of free glucose.
B. 2-position of fructose.
C. Non-reducing end of maltose.
D. Serine-OH group of glycogen synthase.
E. Tyrosine-OH group of glycogenin.
571.
The interconversion of which pair of substrates is used as a regulatory point in
gluconeogenesis?
A. Lactate and pyruvate
B. Dihydroxyacetone phosphate and glyceraldehyde-3-phosphate
C. * Fructose 1,6-bisphosphate and fructose 6-phosphate
D. Phosphoenolpyruvate and 2-phosphoglycerate
E. None of the above
572.
The main function of the pentose phosphate pathway is to:
A. Give the cell an alternative pathway should glycolysis fail.
B. Provide a mechanism for the utilization of the carbon skeletons of excess amino
acids.
C. Supply energy.
D. Supply NADH.
E. * Supply pentoses and NADPH.
573.
The main hormones that regulate the synthesis and decomposition of glycogen
are:
A. Insulin, glucocorticoids, thyroxin;
B. Glucagons, glucocorticoids, vasopressin;
C. * Insulin, glucagons, epinephrine;
D. Glucocorticoids, glucagons, epinephrine.
E. All of the above.
574.
The main precursors for the glucose synthesis in gluconeogenesis are:
A. Lactate, pyruvate, glycerol and cholesterol;
B. * Lactate, pyruvate, glycerol and amino acids;
C. Lactate, pyruvate, glycerol and glycogen;
D. Cholesterol, fatty acids, glycerol and amino acids.
E. The accelerating of glycolysis
575.
The main precursors for the glucose synthesis in gluconeogenesis are:
A. Lactate, pyruvate, glycerol and cholesterol;
B. * Lctate, pyruvate, glycerol and amino acids;
C. Lactate, pyruvate, glycerol and glycogen;
D. Cholesterol, fatty acids, glycerol and amino acids.
E. The accelerating of glycolysis
576.
The organ most responsible for extracting and converting lactic acid to pyruvic
acid, and which ultimately reforms and releases free glucose via the Cori cycle into the
bloodstream, is the
A. Liver.
B. Brain.
C. Cardiac muscle.
D. * Skeletal muscle.
E. Heart
577.
The Pasteur Effect is:
A. The accelerating of glycolysis in the presence of oxygen;
B. * The slowing of glycolysis in the presence of oxygen;
C. The slowing of glycolysis in the absence of oxygen;
D. The accelerating of glycolysis in the presence of 2,6-bisphosphate.
E. The accelerating of glycolysis.
578.
The pentose phosphate pathway has two primary products. They are _________.
A. ATP and NADPH
B. Oxaloacetate and acetyl CoA
C. Sorbitol and fructose
D. * Ribose-5-phosphate and NADPH
E. None of the above
579.
The possible metabolic pathways for pyruvate in anaerobic conditions are:
A. Conversion to lactate or acetyl CoA
B. Conversion to ethanol or acetyl CoA
C. * Conversion to lactate or ethanol
D. Conversion to lactate or ethanol or acetyl CoA.
E. All of the above.
580.
The process of polysaccharides digestion in the gastrointestinal tract is catalized
by:
A. Sucrase
B. Lactase
C. Maltase
D. * D-amilase.
E. None of the above.
581.
The sequence of glucose oxidation to lactate in peripheral tissues, delivery of
lactate to the liver, formation of glucose from lactate in the liver, and delivery of glucose
back to peripheral tissues is known as the ______.
A. Glyoxylate cycle
B. Kreb's cycle
C. * Cori cycle
D. Gluconeogenesis cycle
E. Glycogenolysis
582.
The three control sites in glycolysis are the reactions catalyzed by:
A. Hexokinase, phosphofructokinase 1 and aldolase;
B. Phosphofructokinase 1, aldolase and pyruvate kinase;
C. Hexokinase, aldolase and pyruvate kinase;
D. * Hexokinase, phosphofructokinase 1 and pyruvate kinase.
E. All of the above
583.
Transfer of a high-energy phosphoryl group to ADP, resulting in ATP occurs
when:
A. 1,3 Bisphosphoglycerate -> 3-phosphoglycerate
B. * Phosphoenolpyruvate (PEP) -> pyruvate
C. 3-Phosphoglycerate -> 2-phosphoglycerate
D. Both a and b
E. Only A
584.
Under starvation conditions, about how long does it take in humans for the body
to deplete the glycogen store in the liver?
A. 10 minutes
B. 4 hours
C. * 24 hours
D. 1 week
E. 2 weeks
585.
Unlike liver tissue, muscle and some other tissues differ in regulation of glycogen
metabolism because
A. The enzymes are different
B. There is no effect of glucagon
C. There is no effect of insulin
D. * Inhibitor-1 controls a phosphatase
E. There is no role for cyclic AMP
586.
Vomiting, diarrhea after consuming milk, enlargement of the liver, jaundice,
cirrhosis,cataracts, retardation of the mental development, elevated blood-galactose level,
absence of the galactose 1-phosphate uridyl transferase in red blood cells are the
symptoms of:
A. Lactose intolerance;
B. Hypolactasia;
C. * Galactosemia;
D. All of the above.
E. Diabetes mellitus
587.
Vomiting, diarrhea after consuming milk, enlargement of the liver, jaundice,
cirrhosis,cataracts, retardation of the mental development, elevated blood-galactose level,
absence of the galactose 1-phosphate uridyl transferase in red blood cells are the
symptoms of:
A. Lactose intolerance;
B. Hypolactasia;
C. * Galactosemia;
D. All of the above.
E. Diabetes mellitus
588.
What is a cause of cataracts in the eye lens of individuals with diabetes?
A. * Accumulation of sorbitol and protein precipitation in the lens.
B. Precipitation of glucose not oxidized by glycolysis in the lens.
C. The absence of membrane transport proteins for pyruvate in the lens cells.
D. Lack of regulation of gluconeogenesis in the lens and the accumulation of
fructose.
E. Lack of regulation of gluconeogenesis in the lens and the accumulation of
maltose.
589.
When a muscle is stimulated to contract aerobically, less lactic acid is formed than
when it contracts anaerobically because:
A. Glycolysis does not occur to significant extent under aerobic conditions.
B. Muscle is metabolically less active under aerobic than anaerobic conditions.
C. The lactic acid generated is rapidly incorporated into lipids under aerobic
conditions.
D. Under aerobic conditions in muscle, the major energy-yielding pathway is the
pentose phosphate pathway, which does not produce lactate.
E. * Under aerobic conditions most of the pyruvate generated as a result of
glycolysis is oxidized by the citric acid cycle rather than reduced to lactate.
590.
Which is not a function of the main products of the pentose phosphate pathway?
A. * To maintain the reduced form of iron in hemoglobin.
B. To provide reducing power for the synthesis of fatty acids.
C. To serve as precursors in the biosynthesis of RNA and DNA.
D. To raise the concentration of cAMP.
E. Produce pentoses
591.
Which of the following compounds cannot serve as the starting material for the
synthesis of glucose via gluconeogenesis?
A. * Acetate
B. Glycerol
C. Lactate
D. Oxaloacetate
E. ?-ketoglutarate
592.
Which of the following is a cofactor in the reaction catalyzed by the glycolytic
enzyme glyceraldehyde 3-phosophate dehydrogenase?
A. NADP
B. * NAD
C. ATP
D. Heme
E. Cu++
593.
Which of the following is not regulated in glycolysis?
A. Pyruvate kinase
B. * Phosphoglycerate kinase
C. Hexokinase
D. PFK-1
E. ATP
594.
Which of the following promotes glucose and amino acid uptake by muscle?
A. Adrenaline
B. * Insulin
C. Glucagon
D. Cortisol
E. Glycogen
595.
Which of the following statements about the pentose phosphate pathway is
correct?
A. It generates 36 mol of ATP per mole of glucose consumed.
B. It generates 6 moles of CO2 for each mole of glucose consumed
C. It is a reductive pathway; it consumes NADH.
D. It is present in plants, but not in animals.
E. * It provides precursors for the synthesis of nucleotides.
596.
Which of the following statements is incorrect?
A. Aerobically, oxidative decarboxylation of pyruvate forms acetate that enters the
citric acid cycle.
B. In anaerobic muscle, pyruvate is converted to lactate.
C. In yeast growing anaerobically, pyruvate is converted to ethanol.
D. Reduction of pyruvate to lactate regenerates a cofactor essential for glycolysis.
E. * Under anaerobic conditions pyruvate does not form because glycolysis does not
occur.
597.
Which of the following statements is not true concerning glycolysis in anaerobic
muscle?
A. Fructose 1,6-bisphosphatase is one of the enzymes of the pathway
B. * It is an endergonic process.
C. It results in net synthesis of ATP
D. It results in synthesis of NADH
E. Its rate is slowed by a high [ATP]/[ADP] ratio.
598.
Which of the following substrates cannot contribute to net gluconeogenesis in
mammalian liver?
A. Alanine
B. Glutamate
C. * Palmitate
D. Pyruvate
E. ?-ketoglutarate
599.
Which of the following tissues can survive longest in the absence of adequate
oxygen (anaerobic conditions) by deriving energy from the anaerobic respiration of
glucose molecules?
A. The brain
B. * Cardiac muscle
C. The kidneys
D. Skeletal muscle
E. None of the above
600.
Which one of the following statements about gluconeogenesis is false?
A. For starting materials, it can use carbon skeletons derived from certain amino
acids.
B. * It consists entirely of the reactions of glycolysis, operating in the reverse
direction.
C. It employs the enzyme glucose 6-phosphatase.
D. It is one of the ways that mammals maintain normal blood glucose levels between
meals.
E. It requires metabolic energy (ATP or GTP)
601.
. A deficiency in the synthesis of sphingomyelins or cerebrosides will most likely
result in the proper formation of
A. Cell surfaces
B. Cell to cell communication
C. * Nerve cells
D. Blood groups
E. All of the above
602.
A diet containing this fat is helpful in lowering the blood cholesterol level.
A. * Unsaturated
B. Saturated
C. Vitamin enriched
D. Refined
E. All of the above
603.
A fatty acid not synthesized in man is
A. Oleic
B. Palmitic
C. * Linoleic
D. Stearic
604.
A lipid containing alcoholic amine residue is
A. Phosphatidic acid
B. Ganglioside
C. Glucocerebroside
D. * Sphingomyelin
E. All of the above
605.
A soluble system for synthesis of fatty acids have been isolated from avian liver,
required for the formation of long chain fatty acids by this system is
A. ATP
B. Acetyl CoA
C. NADPH
D. * All of these
E. Both (A) and (B)
606.
Absorption of higher fatty acids in the intestine is performed with the help of
mechanism:
A. simple diffusion
B. facillated diffusion
C. primary active transport
D. pinocytosis as choleic complex
E. secondary active transport
607.
Activation of fatty acids requires all the following except
A. ATP
B. Coenzyme A
C. Thiokinase
D. * Carnitine
E. A and B
608.
Acyl Carrier Protein contains the vitamin:
A. Biotin
B. Lipoic acid
C. * Pantothenic acid
D. Folic acid
E. Thiamine
609.
Acyl carrier protein is involved in the synthesis of
A. protein
B. glycogen
C. * fatty acid outside the mitochondria
D. fatty acid in the mitochondria
E. Both C and D
610.
Acyl-CoA dehydrogenase converts Acyl CoA to ? ??-unsaturated acyl-CoA in
presence of the coenzyme:
A. NAD+
B. NADP+
C. ATP
D. * FAD
E. TPP
611.
Acylsphingosine is also known as
A.
B.
C.
D.
E.
Sphingomyelin
* Ceramide
Cerebroside
Sulphatide
None of these
612.
Adipose tissue lacks
A. Hormone-sensitive lipase
B. * Glycerol kinase
C. cAMP-dependent protein kinase
D. Glycerol-3-phosphate dehydrogenase
E. B and C
613.
Adipose tissue which is a store house for triacyl glycerol synthesis the same using
A. The glycerol released by hydrolysis of triacyl glycerol
B. * The glycerol-3-phosphate obtained in the metabolism of glucose
C. 2-phosphoglycerate
D. 3-phosphoglycerate
E. All of the above
614.
After having fatty food the patient had nausea and steatorrhea. The cause of this
condition can be:
A. amilase insufficiency
B. increase of lipase excretion
C. trypsin synthesis malfunction
D. * lack of bile acids
E. increased acidity of gastric juice
615.
After having fatty food the patient had nausea and steatorrhea. The cause of this
condition can be:
A. amilase insufficiency
B. increase of lipase excretion
C. trypsin synthesis malfunction
D. * lack of bile acids
E. increased acidity of gastric juice
616.
After meal conncentration of chylomicrones in blood of the patient is increased.
Chylomicrones are formed in the ____________________ and their main function is the
__________________________________.
A. wall of intestine; transport of cholesterol;
B. liver; transport of triacylglycerols synthesized in liver;
C. * wall of intestine; transport of dietary triacylglycerols;
D. blood; transport of cholesterol.
E. all of the above.
617.
All long chain fatty acids with even number of carbon atoms are oxidized to a
pool of _________ by ?-oxidation.
A. CO2
B. Propionic acid
C. Acetic acid
D. * Acetyl CoA
E. CoA
618.
An unknown lipid is treated with a mixture of phospholipases A1, A2, C and D.
Since no glycerol is formed after this treatment, the lipid is most likely
A. Phosphatidylethanolamine
B. Phosphatidylcholine
C. Plasmologen
D. * Ceramide
E. A mixture of a and b
619.
can be generated from
A. * The pentose phosphate pathway
B. Glycolysis
C. The citric acid cycle
D. Mitochondrial malate dehydrogenase
E. Citrate lyase
620.
Carboxylation of acetyl—CoA to malonyl — CoA takes place in presence of
A. FAD+
B. Biotin
C. * NAD+
D. NADP+
E. TPP
621.
Carnitine acylcarnitine translocase is present
A. * In the inner mitochondrial membrane
B. In the mitochondrial matrix
C. On the outer surface of inner mitochondrial membrane
D. On the inner surface of inner mitochondrial membrane
E. In cytoplasm
622.
Carnitine is synthesized from
A. * Lysine and methionine
B. Glycine and arginine
C. Aspartate and glutamate
D. Proline and hydroxyproline
E. None of the above
623.
Cerebrosides contain all the following except
A. Galactose
B. * Sulphate
C. Sphingosine
D. Fatty acid
E. B and C
624.
Chylomicron remnants are catabolised in
A. Intestine
B. Adipose tissue
C. * Liver
D. Liver and intestine
E. Pancreas
625.
Co-lipase is a
A. Bile salt
B. Vitamin
C. * Protein
D. Phospholipid
E. Lipoprotein
626.
Concentration of phospholipids in blood of the patient is decreased. Lecithins are
composed of
A. * Glycerol + Fatty acids + Phosphoric acid + Choline
B. Glycerol + Fatty acids + Phosphoric acid + Ethanolamine
C. Glycerol + Fatty acids + Phosphoric acid + Serine
D. Glycerol + Fatty acids + Phosphoric acid + Beaine
E. All of these
627.
Conncentration of LDL in blood of the patient is increased. Low density
lipoproteins transport ________________ from __________ to _________________.
A.
B.
C.
D.
E.
triacylglycerols; intestine; liver
* cholesterol; liver; peripheral tissues;
cholesterol; peripheral tissues; liver
triacylglycerols; liver; adipose tissue and muscles
triacylglycerols; liver; muscles
628.
De novo synthesis of fatty acids is catalysed by a multi-enzyme complex which
contains
A. One-SH group
B. Two-SH groups
C. Three-SH groups
D. * Four-SH groups
E. Five –SH groups
629.
De novo synthesis of fatty acids occurs in
A. * Cytosol
B. Mitochondria
C. Microsomes
D. EPR
E. All of these
630.
De novo synthesis of fatty acids requires all of the following except
A. Biotin
B. NADH
C. Panthothenic acid
D. * ATP
E. Multienzyme complex
631.
Dietary fats after absorption appear in the circulation as
A. HDL
B. VLDL
C. LDL
D. * Chylomicron
E. None of the above
632.
Each of the following is a principle hormonal regulator of fatty acid metabolism,
except:
A. Glucagon
B. Epinephrine
C. Insulin
D. All of the above
E. * None of the above
633.
Elevated levels of the hormone ________ stimulates the conversion of
triacylglycerols stored in adipose cells to free fatty acids and monoacylglycerols to
provide energy when carbohydrate stores are depleted.
A. insulin
B. testosteron
C. * epinephrine
D. ergosterol
E. STH
634.
Ethanolamine, serine and choline can be cleaved from glycerophospholipids by
treatment with
A. Phospholipase A1
B. Phospholipase A2
C. Phospholipase B
D. Phospholipase C
E. * Phospholipase D
635.
Extramitochondrial synthesis of fatty acids occurs in
A. Mammary glands
B. Lungs
C. Brain
D. * All of these
E. B and c
636.
Fat depots are located in
A. Intermuscular connective tissue
B. Mesentary
C. Omentum
D. * All of these
E. A and C
637.
Fatty acid synthesis takes place in the presence of the coenzyme:
A. NAD+
B. Reduced NAD
C. NADP+
D. * Reduced NADP
E. TPP
638.
Fatty acids can not be converted into carbohydrates in the body, as the following
reaction is not possible:
A. Conversion of glucose-6-phosphate into glucose
B. Fructose 1, 6 diphosphate to fructose-6-phosphate
C. * Transformation of acetyl CoA to pyruvate
D. Formation of acetyl CoA from fatty acids
E. Both C and D
639.
For TAG synthesis glycerol converts into active form. Glycerol is transformed
into active form with the enzyme:
A. phosphatidate phosphatase
B. * glycerol kinase
C. glycerol phosphate dehydrogenase
D. glycerol phosphate acyltransferase
E. diglyceride-acyl-transferase
640.
For the patient was prescribed bile preparation for improvement of fatty food
digestion. Which components of the preparation participate in fat emulsification?
A. * bile acid salt
B. fatty acids
C. cholesterol and it's esters
D. bilirubin monoglucuronides
E. diglycerides
641.
For the patient with diagnosis atherosclerosis “Linetol” is prescribed, which
contains essential fatty acids. Which of the below-mentioned acids surely is a part of it?
A. stearic acid
B. palmitic acid
C. * linoleic acid
D. oleic acid
E. crotonic acid
642.
For the patient with diagnosis atherosclerosis “Linetol” is prescribed, which
contains essential fatty acids. Which of the below-mentioned acids surely is a part of it?
A. stearic acid
B. palmitic acid
C. * linoleic acid
D. oleic acid
E. crotonic acid
643.
Free glycerol cannot be used for triglyceride synthesis in
A. Liver
B. Kidney
C. Intestine
D. * Adipose tissue
E. Pancreas
644.
Gangliosides are complex glycosphingolipids found in
A. Liver
B. * Brain
C. Kidney
D. Muscle
E. Pancreas
645.
Glycerol is converted into glycerol-3-phosphate by
A. Thiokinase
B. Triokinase
C. * Glycerol kinase
D. Glycerol phosphatase
E. All of these
646.
Glycerol is converted to ___________ when it is used for gluconeogenesis.
A. dihydroxyacetone phosphate
B. phosphoenolpyruvate
C. oxaloacetate
D. * 3-phosphoglycerate
E. none of the above.
647.
Glycerol is transformed into active form with the help of enzyme:
A. phosphatidate phosphatase
B. * glycerol kinase
C. glycerol phosphate dehydrogenase
D. glycerol phosphate acyltransferase
E. diglyceride-acyl-transferase
648.
In a liver of 55 years old patient fatty acids synthesis is active. When the liver is
actively synthesizing fatty acids, a concomitant decrease in ? oxidation of fatty acids is
due to
A. * Inhibition of a translocation between cellular compartments
B. Inhibition by an end product
C. Activation of an enzyme
D. Detergent effects
E. Decreases in adipocyte lipolysis
649.
in adipose tissue
A. 2 mol of triacylglycerides is released
B. 2 mol of free fatty acids is released
C. * 1 mol of glucose can be synthesized in gluconeogenesis
D. 1 mol of triacylglyceride is released
E. 3 mol of acyl CoA is produced
650.
In an organism of 37 years old patient fatty acids synthesis is active. Which of the
following is a true statement for fatty acid synthesis?
A. It occurs in the mitochondria.
B. The reducing power for synthesis is supplied by NAD and ubiquinone.
C. Both a and b.
D. None of the above.
E. * The reducing power for synthesis is supplied by NADPH+
651.
In an organism of 40 years old patient fatty acids synthesis is active. The main
sources of NADPH for fatty acid biosynthesis is:
A. TCA cycle
B. oxidative phosphorylation
C. * the pentose phosphate pathway
D. glycolysis
E. All of the above.
652.
In an organism of 40 years old patient mobilisations of lipids is active. Elevated
levels of the hormone ________ stimulates the conversion of triacylglycerols stored in
adipose cells to free fatty acids and monoacylglycerols to provide energy when
carbohydrate stores are depleted.
A. insulin
B. glucagon
C. * epinephrine
D. ergosterol
E. somatotropin
653.
In an organism of 43 years old patient mobilisations of lipids and fatty acids
oxidation are active. How many cycles of ?-oxidation are required to completely process
a saturated C18 fatty acid?
A. 6
B. * 8
C. 9
D. 18
E. 7
654.
In an organism of 47 years old patient mobilisations of lipids and fatty acids
oxidation are active. How many QH2 and NADH are produced by one round of the ?oxidation pathway?
A. * 1 each
B. 1 QH2 and 2 NADH
C. 2 each
D. 2 QH2 and 1 NADH
E. all of the above
655.
In an organism of 47 years old patient mobilisation of lipids is active.
Tryacylglycerinlipase of fatty tissue is activated by:
A. adenosine triphosphate
B. guanosine triphosphate
C. adenosine diphosphate
D. * cyclic adenosine monophosphate
E. guanosine diphosphate
656.
In an organism of 55 years old patient with hyperfunction of pancreas takes plase
active synthesis of fatty acids Which of the following is the regulated step of fatty acid
synthesis in eukaryotes?
A. * Carboxylation of acetyl CoA.
B. Transportation of mitochondrial acetyl CoA into the cytosol.
C. Assembly of the fatty acid chain.
D. All of the above.
E. None of the above.
657.
In an organism of 55 years old patient fatty acids oxidation is active. Splitting off
acetyl-CoA in the final reaction of S-oxidation of fatty acids is performed by the enzyme:
A. dehydrogenase
B. enolase
C. hydrase
D. lipase
E. * thiolase (acetyl-CoA-acyltransferase)
658.
In an organism of 55 years old patient mobilisations of lipids and fatty acids
oxidation are active. Which of the below-mentioned metabolites is formed by oxidation
of fatty acids with odd amount of carbon atoms:
A. * propionyl-CoA
B. butyryl-CoA
C. malonyl-CoA
D. enoil-CoA
E. acetacetyl-CoA
659.
?In the blood of a patient is decreased amount of phospholipinds, increased
concentration of cholesterol, observed the symptoms of prostaglandin lack. What can
cause such events?
A. limited usage of carbohydrates
B. * limited usage of polyunsaturated fatty acids
C. D hypovitaminosis
D. excess of lipids in food
E. excess of carbohydrates in food
660.
In the blood of a patient is decreased amount of phospholipinds, increased
concentration of cholesterol, observed the symptoms of prostaglandin lack. What could
cause such events?
A. limited usage of carbohydrate
B. * limited usage of polyunsaturated fatty acids
C. D hypovitaminosis
D. excess of lipids in food
E. excess of carbohydrates in food
661.
In the blood of a patient is decreased amount of phospholipinds, increased
concentration of cholesterol, observed the symptoms of prostaglandin lack. What can
cause such events?
A. limited usage of carbohydrates
B. * limited usage of polyunsaturated fatty acids
C. D hypovitaminosis
D. excess of lipids in food
E. excess of carbohydrates in food
662.
In the blood of a patient there are decreased amount of phospholipids, increased
concentration of cholesterol, observed prostaglandins lack. What can cause such events?
A. limited usage of carbohydrates
B. * limited usage of polyunsaturated fatty acids
C. D hypovitaminosis
D. excess of lipids in food
E. excess of carbohydrates in food
663.
In the blood of a patient there is decreased amount of phospholipids, increased
concentration of cholesterol, observed prostaglandins lack. What can cause such events?
A. limited usage of carbohydrate
B. * limited usage of polyunsaturated fatty acids
C. D hypovitaminosis
D. excess of lipids in food
E. excess of carbohydrates in food
664.
is conjugated, reacts directly, and is a major component of bile?
A. * Bilirubin diglucuronide
B. Stercobilin
C. Biliverdin
D. Urobilinogen
E. Heme
665.
is most often due to
A. Lactose intolerance
B. Glycogen storage diseases
C. Antibody abnormalities
D. * Deficiency of fatty acid desaturase greater than
E. Deficiency of chylomicron and VLDL production
666.
Lisophospholipids, formed after action of phospholipase A2, have the following
feature:
A. activate lipase
B. * hemolytic
C. form conjugates with bile acids
D. participate in phospholipids resynthesis
E. accompany absorption of fatty acids
667.
mevastatin therapy. Which of the following will be a result of this therapy?
A. Low blood glucose
B. * Low blood LDLs
C. High blood cholesterol
D. High blood glucose
E. Low oxidation of fatty acids
668.
Patient suffers from disorders of lipid digestion. What are the functions of bile
salts in lipid digestion?
A. * emulsification of lipids; activation of lipase;
B. emulsification of lipids; decompose the cholesteryl esters;
C. activation of phospholipase A2; activation of cholesterol esterase;
D. inhibition of lipase; inhibition of phospholipase A2.
E. all of the above.
669.
The amount of phospholipids in the blood plasma of 45 years old patient is
normal. Choose correct result:
A. * 1,5-3,6 mmol/l
B. 2,0-5,0 mmol/l
C. 1,2-2,5 mmol/l
D. 0,7-2,0 mmol/l
E. 7,0-8,0 mmol/l
670.
The patient was prescribed bile preparation for improvement of fatty food
digestion. Which components of the preparation participate in fat emulsification?
A. * bile acid salt
B. fatty acids
C. cholesterol and it's esters
D. bilirubin monoglucuronides
E. diglycerides
671.
Why snake venom causes the lysis of erythrocytes?
A. contains hemolytic toxins which directly destroy the erythrocytes membranes;
B. * contains phospholipase A2 catalyzing the hydrolysis of glycerophospholipids
and formation of lysophosphoglycerides which can act as detergents and disrupt
cellular membranes;
C. contains lipase catalyzing the hydrolysis of triacylglycerols in the cellular
membranes;
D. contains cholesteryl esterase catalyzing the hydrolysis of cholesterol esters in the
cellular membranes.
E. none of the above.
672.
When can the production of ketone bodies occur? Which is/are true?
A. If you eat too much sugar and less of saturated butter
B. In diabetes patients
C. If you eat too much bacon and less sugar
D. * If you are starving for a longer time period
E. In pellagra patients
673.
A high carbohydrate, low-fat diet will:
A. * Promote the synthesis of fatty acids by inducing the synthesis of acetyl CoA
carboxylase.
B. Favor the oxidation of stored fatty acids by inducing the synthesis of lipoprotein
lipase.
C. Promote the synthesis of fatty acids by repressing synthesis of carnitine-palmitoyl
transferase.
D. Favor the oxidation of fatty acids by repressing the synthesis of fatty acid
synthase.
E. None of the above
674.
A man of 47 years suffers from insulin-dependent diabetes, on which background
has evolved metabolic acidosis. What process' malfunction majorily helps the
development of acidosis?
A. Ketone bodies synthesis
B. * Ketone bodies utilization
C. Glycogen decomposition
D. Glycogen synthesis
E. Oxidative phosphorylation
675.
A patient, which visited a doctor, has increased level of glucose in blood and
urine. Suspected is diabetes mellitus. Which changes in lipid metabolism can cause this
disease?
A. Hyperketonemia
B. Hypercholesterolemia
C. * Hypoketonemia, ketonuria
D. Hyperphospholipidemia, hyperketonemia
E. Hypophospholipidemia , hypoketonemia
676.
A stroke is similar to a heart attack in all of the following ways EXCEPT:
A. It affects the brain.
B. The risk can be reduced by lifestyle changes.
C. It is a blockage of major arteries.
D. * It results in the death of cells
E. A, B, C
677.
Adiposogenital dystrophy is caused by the lack of secretion of:
A. Oxytocin
B. Vasopressin
C. Gonadotropic hormone
D. * Thyrotropic hormone
E. Melanotropic hormone
678.
After observation of a patient with diabetes mellitus were discovered ketonemia
and ketonuria. Mark, which of the below-mentioned matters is the precussor of ketone
bodies?
A. * Acetyl-CoA
B. Oxaloacetate
C. ?-ketoglutarate
D. Cholesterol
E. Unsaturated fatty acids
679.
All of the following are functions of dietary fat, except
A. Facilitating the absorption of fat-soluble vitamins.
B. Serving as the major source of fuel for RBCs.
C. Acting as stored energy.
D. * Being essential to the synthesis of phospholipid that is a major component of
cell membranes.
E. Facilitating the absorption of water-soluble vitamins.
680.
All of the following are true about arteriosclerosis EXCEPT:
A. It is a collection of fatty deposits inside a blood vessel.
B. It is called "hardening" of the arteries.
C. It is a blockage of an artery.
D. * It affects all blood vessels equally
E. Only A, B, C
681.
All the following statements about carnitine are true except
A. It can be synthesised in the human body
B. It can be synthesized from methionine and lysine
C. It is required for transport of short chain fatty acids into mitochondria
D. * Its deficiency can occur due to haemodialysis
E. can be synthesized from treonin and lysine
682.
All the following statements about ketone bodies are true except
A. * Their synthesis increases in diabetes mellitus
B. They are synthesized in mitchondria
C. They can deplete the alkali reserve
D. They can be oxidized in the liver
E. Only C
683.
Anti-inflammatory corticosteroids inhibit
A. Phospholipase A1
B. * Phospholipase A2
C. Cyclo-oxygenase
D. Lipo-oxygenase
E. Pancreatic lipase
684.
Atherosclerosis and coronary heart diseases are associated with the diet:
A. * High in total fat and saturated fat
B. Low in protein
C. High in protein
D. High in carbohydrate
E. High in vitamins
685.
Bile acids are excreted into the intestine where they become bile salts due to:
A. * The alkaline environment within the intestine
B. The acidic environment of the stomach
C. Alkaline hydrolysis
D. Formation of esters
E. Formation of amides due to the relatively high temperature and low rate of flow
686.
By analysis of patient's lipogram was discovered the increase of some lipoproteins
level. Choose the most atherogenic representative of lipoproteins:
A. LDL
B. * HDL
C. Chylomicrons
D. LDDL
E. Albumins
687.
?Cardiovascular function is most commonly impaired by which disease?
A. Coronary heart disease
B.
C.
D.
E.
Arteriosclerosis
Stroke
Hypertension
* All of the above
688.
Cholesterol circulates in blood stream chiefly as
A. Free cholesterol
B. Ester cholesterol
C. Low density lipoproteins
D. * Low density lipoproteins and high density lipoproteins
E. Salts of cholesterol
689.
Doctor prescribed to the patient, exhausted after heavy disease, small doses of
hormones on the background of high-calorie diet. What hormone was prescribed?
A. * Adrenalin
B. Insulin
C. Thyroxine
D. Aldosterone
E. Vasopressin
690.
Elder patient has a recommendation with the aim of prevention liver fatty seepage
to use in food cheese. What essential amino acid, necessary for phospholipids synthesis,
there is in cheese?
A. Arginine
B. Proline
C. Valine
D. Lysine
E. * Methionine
691.
Fat is important to the body for all of the following reasons EXCEPT
A. That it provides essential amino acids.
B. That it stores energy for later use.
C. * That it carries fat-soluble vitamins.
D. That it helps to maintain cell membranes
E. Only B and D
692.
Fatty acid oxidation occurs:
A. Only in adipose tissue
B. * Within liver parenchyma
C. Within mitochondria and peroxisomes of many tissues
D. Only within arterial epithelium
E. Only within venous epithelium
693.
Fatty acid oxidation occurs:
A. Only in adipose tissue
B. * Within liver parenchyma
C. Within mitochondria and peroxisomes of many tissues
D. Only within arterial epithelium
E. Only within venous epithelium
694.
Hyperketonemia is observed in the following cases, but:
A. Starvation
B. Diabetes mellitus
C. Excessive usage of carbohydrates
D. Long stress
E. * Thyrotoxicosis
695.
Hypocholesterolaemia can occur in
A. * Hyperthyroidism
B. Nephrotic syndrome
C. Obstructive jaundice
D. Diabetes mellitus
E. Diabets insipidus
696.
If you wanted to locate some cholesterol within a healthy body, you might expect
to find it:
A. * In the cytoplasm of mitochondria
B. In the cytoplasm of chloroplasts
C. In membranes
D. In the aqueous humor of the eye
E. In pancreatic lipase
697.
Ketone bodies can be used as the source of energy in the following organ(s):
A. * In the brain (after a week of fasting it adapts to use it)
B. In the heart
C. In the liver
D. In kidney
E. None of the above
698.
Obesity generally reflects excess intake of energy and is often associated with the
development of
A. Nervousness
B. * Non-insulin dependent diabetes mellitus
C. Hepatitis
D. Colon cancer
E. Rickets
699.
Obesity increases the risk of
A. Hypertension
B. Diabetes mellitus
C. Ishemic disease
D. * All of these
E. Srtoke
700.
Obesity is accumulation of _______ in the body.
A. Water
B. NaCl
C. * Fat
D. Proteins
E. Vitamins
701.
Oliguria can occur in
A. Diabetes mellitus
B. * Diabetes insipidus
C. Acute glomerulonephritis
D. Chronic glomerulonephritis
E. Liver diseases
702.
One of the leading pathogenetic chains in the development of radial pathology is
the intensification of free-radical oxidation processes. What matters are the main source
of free radicals formation?
A. Water
B. * Lipids
C. Carbohydrates
D. Proteins
E. Metal ions
703.
Patient has ketonemia and ketonuria, amount of glucose in blood 3,5 mM/l,
cholesterol – 4,5 mM/l. What malfunctions could cause this?
A. * Dabetes mellitus
B.
C.
D.
E.
Crbohydrates deficit in nutrition
Aherosclerosis
Ecessive usage of fats
Liver disease
704.
Patient with hard form of diabetes has increase of ketone bodies amount in blood.
The main reason of ketonemia development is considered:
A. * Decrease if intracellular oxaloacetate concentration
B. Inhibition of triacylglycerol lipase
C. Activity inhibition of acetyl-CoA-acetyltransferase
D. Activation of Krebs cycle enzymes
E. Stimulation of glycogen synthesis in liver
705.
Smoking increases an individual's chance for heart disease by:
A. Decreasing your body's ability to clot blood.
B. Decreasing the amount of fat deposits around arterial walls
C. Increasing the chance of an irregular heartbeat.
D. * Decreasing heart rate and blood pressure.
E. None of the above
706.
Splitting off acetyl-CoA in the final reaction of S-oxidation of fatty acids is
performed under influence of enzyme:
A. Dehydrogenase
B. Enolase
C. Hydrase
D. Lipase
E. * Thiolase (acetyl-CoA-acyltransferase)
707.
The amount of total lipids in blood – 30 g/l, cholesterol – 9 mmol/l. The blood
plasma is alkaline, by blood centrifugation on the surface is formed white layer. Amount
increase of what transportation forms of lipids in the blood takes place in this situation?
A. Chylomicrons
B. ?-lipoproteins
C. * C-lipoproteins
D. Pre-D-lipoproteins
E. Albumins
708.
The average male human body contains about 19% fat. For purposes of
discussion, physicians often refer to the average man as a "70 Kg man," (actually a little
low by modern standards of obesity). How many pounds of fat would be present in the
body of a 70 Kg man?
A. 13
B. * 51
C. 154
D. 2,2
E. 29
709.
The body needs fatty acids to:
A. Produce cell membranes.
B. Make myelin sheaths.
C. Absorb certain vitamins.
D. * All of the above
E. Precusor of carbohydrates, amino acids
710.
The observation of a patient after radiolesion showed increased amount in the
blood of malonic dialdehyde, which proves the activation of lipids peroxidation. What
violations in cell membranes this can cause?
A. Cholesterol oxidation
B. Transportation proteins structure change
C. Destruction of carbohydrate components
D. Activation of Na+, K+-ATP-ase
E. * Destruction of phospholipids
711.
The observation of a patient showed deficient activity of ferment lecithin
cholesterol acyltransferase (LCAT). Possible result is:
A. Fatty liver degeneration
B. Hyperketonemia
C. * Hypocholesterolemia
D. Hyperlipemia
E. Atherogenic hypocholesterolemia
712.
The observation of a patient showed high amount of cholesterol in ?-lipoprotein
fraction. This can result in:
A. * Ischemic heart disease
B. Hypovitaminosis
C. Ketonemia
D. Steatorrhea
E. Fatty liver degeneration
713.
The observation of a patient showed symptoms of hypovitaminosis B5. By this is
observed malfunction of lipids metabolism, but:
A. Cholesterol and fatty acids synthesis
B. Ketone bodies oxidation
C. * Transportat of fatty acids to mitochondria
D. Glycerine oxidation
E. Fatty acids oxidation
714.
The patient got into the habit of having several uncooked eggs, which contain
antivitamin of biotin – avidin. What malfunctions of lipid metabolism can be the result of
this?
A. Cholesterol biosynthesis
B. Lipids absorption
C. * Fatty acids biosynthesis
D. Glycerine oxidation
E. Lipids transportation in blood
715.
The patient has hypertension, atherosclerotic vessels affection. Name what lipid
usage he needs to decrease in daily food allowance:
A. Cholesterol
B. * Oleic acid
C. Lecithin
D. Mono oleate glyceride
E. Phosphatidyl serine
716.
The patient have symptoms of general adiposity, atherosclerotic changes. From
the list of possible reasons for this should be excluded:
A. Lack of carbohydrates in nutrition
B. Smoking
C. Alcohol abuse
D. Hereditary inclination
E. * Excess of carbohydrates and lipids in nutrition
717.
The patient with burns was prescribed in the treatment preparation complex
vitamin E. What is the base of its action by this pathology?
A. Activation of tissue breathing
B. Normalization of metabolism in muscles
C. * Anti-oxidant action
D. Activation of lipids peroxidation
E. Decrease of organism dehydration
718.
The paсient possibly has atherosclerosis. What feature helped to prove this?
A. Increase of general lipids in blood
B. Increase of ketone bodies in blood
C. Increase of high density liporoteins
D. Decrease of phospholipids in blood
E. Increase of low density liporoteins
719.
The vitamin whose cofactors are involved in carrying single carbons for “onecarbon metabolism” is:
A. * Folate or folic acid
B. Nicotinamid
C. Biotin
D. Ascorbic acid
E. 1,25-dihydroxicholecalciferol
720.
To prevent the development of atherosclerosis is possible by means of:
A. * Excessive usage of carbohydrates
B. Limitation of carbohydrates, lipids
C. Excess of lipids in food
D. Limitation of protein in food
E. Limitation of vegetable oil in food
721.
Which food does not have a lot of saturated fat?
A. * Coconut oil.
B. Whole milk.
C. Chicken, with skin.
D. Butter.
E. Whole wheat bread.
722.
Which of the following can be synthesized in the human body if precurors are
available?
A. Oleic acid
B. Palmitoleic acid
C. Arachidonic acid
D. * All of these
E. None of the above
723.
Which of the following condition is characterized by ketonuria but without
glycosuria?
A. Diabetes mellitus
B. Diabetes insipidus
C. * Prolonged starvation
D. Addison’s disease
E. Pellagra
724.
Which of the following factors makes it harder for an obese person to lose
weight?
A. * An increase in metabolism that increases the appetite
B. An increase in heat loss from the body that requires more food intake
C. An increase in taste receptors
D. An increase in thyroxine levels as fat levels accumulate
E. An increase in alpha receptors (the kind that favor fat accumulation) in fat cells
725.
Which of the following major risk factors of heart disease cannot be controlled?
A. * Smoking
B. Hypertension
C. Sedentary lifestyle
D. Heredity
E. All of the above
726.
Which of the following statements is NOT true regarding fatty acids?
A. Fatty acids dissolve in nonpolar solvents.
B. * Triglycerides are esters of fatty acids.
C. Most naturally occurring fatty acids have trans double bonds.
D. Fatty acids are biosynthesized from acetate.
E. C and D
727.
Which of these is a general feature of the lipid bilayer in all biological
membranes?
A. Polar, but uncharged, compounds readily diffuse across the bilayer.
B. Individual lipid molecules are free to diffuse laterally in the surface of the bilayer.
C. Individual lipid molecules in one face (monolayer) of the bilayer readily diffuse
(flip-flop) to the other monolayer.
D. * The bilayer is stabilized by covalent bonds between neighboring phospholipid
molecules.
E. Only C
728.
Which one of the following statements is FALSE?
A. Skeletal muscle and the brain lack glucose-6-phosphatase.
B. Acetoacetate and ?-hydroxybutyrate serve as the major source of energy for the
brain during starvation.
C. * Water is an essential nutrient.
D. The essential polyunsaturated fatty acids are palmitoleic and linoleic acids.
E. The principal function of water-soluble vitamins is to serve as coenzymes for
several types of enzymes.
729.
Women of 45 years after long starvation has hyperketonemia. Where is performed
the synthesis of ketone bodies?
A. * Mitochondria of hepatocyte
B. Cytoplasm of hepatocyte
C. Mitochindria of cardiomyocytes
D. Nucleus of cardiomyocytes
E. Cytoplasm of adipocytes
730.
Worker of dry-cleaner's has fatty liver degeneration. What matter synthesis
malfunction in the liver can cause such pathology?
A. Urea
B. * Phosphatidylcholine
C. Phosphatidic acid
D. Cholic acid
E. Tristearin
731.
?-Oxidation was discovered by Knoop when he fed dogs fatty acids labeled with a
benzene ring at the end of the molecule opposite the -COOH group. Metabolism could
not proceed beyond the phenyl group. Dogs fed phenylbutyric acid would produce urine
containing:
A. Phenylacetic acid
B. Benzoic acid
C. * Phenylpyruvic acid
D. Phenyllactic acid
E. Benzene
732.
The amount of total acidity in gastric juice of a patient is normal. Which of the
listed numbers is true in this case?
A. A.30-40 mM/l
B. * B.40-60 mM/l
C. 20-30 mM/l
D. 30-50 mM/l
E. 20-40 mM/l
733.
A 60 year old patient has hyperplasia of G-cells of antral part of stomach. What
changes in gastric juice are most possible for this pathology?
A. * Hyperchlorhydria
B. Hypochlorhydria
C. Achlorhydria
D. Achylia
E. Presence of lactic acid
734.
A healthy 70 kg man eats a well balanced diet containing adequate calories and
62.5 g of high quality protein per day. Measured in grams of nitrogen, his daily nitrogen
balance would be
A. +10 g
B. +6.25 g
C. * 0 g
D. –6.25 g
E. None of the above
735.
A lipotropic factor was prescribed for the patient with liter cirrhosis. Which amino
acid is a lipotropic factor?
A. Lysine
B. Leucine
C. Tryptophan
D. * Methionine
E. All of these
736.
A patient suffers from intensive decay of proteins. Name the compound in the
urine, which is a test of protein putrefaction processes in the intestine:
A. Urates
B. Urea
C. Creatinine
D. * Indican
E. Lactic acid
737.
A phenylketonuria of the newborn was diagnosed. All the following are true about
phenylketonuria except
A. Deficiency of phenylalanine hydroxylase
B. Mental retardation
C. * Increased urinary excretion of p-hydroxyphenyl pyruvic acid
D. Decrease serotonin formation
E. C and D
738.
After burns cause the development of negative nitric balance of a 40 year old
patient took place that was the result of increase of:
A. Glycolysis
B. Lipolysis
C. * Proteolysis
D. Phosphorolysis
E. Fibrinolysis
739.
By decarboxylation of histidine in an organism of 9 year old child in the state of
allergic shock is (are) formed:
A. Tyramine
B. * Histamine
C. Putrescine
D. Cadaverine
E. Serotonine
740.
Coenzyme of amino acids decarboxylases is:
A. Thymidine diphosphate
B. Favin adenine dinucleotide
C. Favin mononucleotide
D. HS-CoA
E. * PALP
741.
essential amino acid?
A. Alanine
B. Glycine
C. Tyrosine
D. * Tryptophan
E. Both A and D
742.
GABA (gamma aminobutyric acid), which belongs to inhibiting mediators of
central nervous system, is a product of glutamic decarboxylation. What vitamin
prescription is appropriate by convulsive state, caused by decrease if GABA formation?
A. B1
B. B9
C. * B6
D. B5
E. B2
743.
Into the hospital was carried 37 year old man with symptoms of achylia gastrica.
Achylia gastrica is said to be when absence of
A. Pepsin only
B. * Both pepsin and HCl
C. HCl only
D. Bile
E. None of these
744.
Into the hospital was carried 7 years old child in the state of allergic shock, which
evolved after wasp's bite. In the blood increased concentration of histamine. This amine
is formed as a result of reaction of:
A. Dehydration
B. Deamination
C. Reduction
D. * Decarboxylation
E. Hydrooxidation
745.
N-end amino acids in the proteins splitt off:
A. Dipeptidase
B. Carbooxypeptidase
C. * Aminopeptidase
D. Elastase
E. Endopeptidase
746.
Patient has positive nitric balance. The reason of this can be:
A. Starvation
B. Tuberculosis
C. * Pregnancy
D. Malignant neoplasms
E. AIDS
747.
Patient has the diagnosis “malignant carcinoid”, amount of serotonine in blood
increased greatly. Name amino acid, able to form the given biogenic amine:
A. Alanine
B. * 5-oxytryptophane
C. Leucine
D. Threonine
E. Methionine
748.
Patient on a vegetarian diet has negative nitric balance, hyperproteinemia,
affection of colloid-osmotic pressure and water-salt metabolism by normal function of
alimentary canal. This was caused by:
A. * Monotonous protein nutrition
B. Monotonous carbohydrate nutrition
C. Lack of unsaturated fatty acids
D. Lack of phospholipids in food
E. Lack of vitamins in food
749.
?Patient with enterocolitis has affected protein adoption. What mechanism of
amino acids absorption is affected?
A. Pinocytosis
B. Primary active transport
C. Simple diffusion
D. * Secondary sodium-dependent transport
E. Phagocytosis
750.
The total acidity in gastric juice of a 40 year old patient is high. Which of the
listed numbers is true in this case?
A. 30-40 mM/l
B. * 60-80 mM/l
C. 20-30 mM/l
D. 30-50 mM/l
E. 20-40 mM/l
751.
The 45 year old man suffers from stomach ache due to high acidity of gastric
juice. The pH of gastric juice becomes low in
A. Hemolytic anemia
B. * Pernicious anemia
C. Both (A) and (B)
D. Jaundice
E. None of these
752.
The 75 year old man suffers from negative nitrogenous balance due to lack of
essential amino acids. The essential amino acids
A. Must be supplied in the diet because the organism has lost the capacity to aminate
the corresponding ketoacids
B. * Must be supplied in the diet because the human has an impaired ability to
synthesize the carbon chain of the corresponding ketoacids
C. Are identical in all species studied
D. Are defined as those amino acids which cannot be synthesized by the organism at
a rate adequate to meet metabolic requirements
E. Both B and D
753.
The newborn suffers from improper milk digestion due to lower activity of rennin.
Rennin acts on casein of milk in infants in presence of
A. Mg++
B. Zn++
C. Co++
D. * Ca++
E. Both C and D
754.
The patient's Ritis' ratio (AsAT\AlAT) equals 0,8. Which disease does it testify?
A. * Hepatitis
B. Pancreatitis
C. Gastritis
755.
756.
757.
758.
759.
760.
761.
762.
D. Cardiac infarction
E. Nephritis
The patient's Ritis' ratio (AsAT\AlAT) equals 2,8. Which disease does it testify?
A. Hepatitis
B. Pancreatitis
C. Gastritis
D. * Cardiac infarction
E. Nephritis
What type of covalent bonds link the amino acids in a protein?
A. * Peptide bonds
B. Hydrogen bonds
C. Ionic bonds
D. Glycosidic bonds
E. Ester bonds
Which of the following is not an amino acid?
A. Glutamic acid
B. Aspartic acid
C. Glutamine
D. * Palmitic acid
E. Leucine
A dietary deficiency of tryptophan and nicotinate leads to
A. Beri Beri
B. Xerophthalmia
C. Anemia
D. * Pellegra
E. Rickets
All the following statements about pepsin are correct, except
A. It is smaller than pepsinogen
B. It is formed by the action of HCl on its precursor
C. Its optimum pH is 1.0–2.0
D. * It hydrolyses the C-terminal and N-terminal peptide bonds of proteins
E. Its optimum pH is 10–12
Along with CO2, NH3 and ATP the aminoacid that is needed in urea cycle is
A. Alanine
B. Isoleucine
C. * Aspartate
D. Glycine
E. Valine
ATP is required in following reactions of urea cycle:
A. Synthesis of carbamoyl phosphate and citrulline
B. * Synthesis of citrulline and argininosuccinate
C. Synthesis of argininosuccinate and arginine
D. Synthesis of carbamoyl phosphate and argininosuccinate
E. All of the above
by carbamoyl phosphate synthetase I is incorrect?
A. The enzyme catalyzes the rate-limiting reaction in the urea cycle.
B. * Raction is allosterically activated by N-acetylglutamate.
C. The reaction is reversible.
D. The enzyme incorporates CO2 into carbamoyl phosphate.
E. The reaction requires two high energy phosphates for each carbamoyl phosphate
molecule synthesized.
763.
Child, who for a long time had products of vegetable origin, has growth
inhibition, anemia, liver and kidney affection, skin and hair reddening. The cause of this
condition is:
A. Lack of lipids in food
B. * Lack of essential amino acid in food
C. Lack of carbohydratesin food
D. Lack of macrocells in food
E. Lack of fats in food
764.
?Control of urea cycle involves the enzyme:
A. * Carbamoyl phosphate synthetase
B. Ornithine transcarbamoylase
C. Argininosuccinase
D. Arginase
E. Fumarase
765.
Cyanide, a potent human toxin, blocks electron flow in electron transport by
binding to Fe2+ . The Fe2+ ion is found in which of the following?
A. Coenzyme Q
B. FADH2
C. Ubiquinone
D. Acetyl – SCoA
E. * Catalase
766.
Cystinuria results from inability to
A. Metabolise cysteine
B. Convert cystine into cysteine
C. Incorporate cysteine into proteins
D. * Reabsorb cystine in renal tubules
E. Only A
767.
Cytosolic and mitochondrial carbamoyl phosphate synthetase have the following
similarity:
A. Both use ammonia as a substance
B. Both provide carbamoyl phosphate for urea synthesis
C. * Both require N-acetylglutamate as an activator
D. Both are allosteric enzymes
E. Both provide carbamoyl phosphate for pirimidine synthesis
768.
Exopeptidases are:
A. Pepsin, trypsin
B. Elastase, colagenase
C. * Carboxypeptidases, aminopeptidases
D. Chymotrypsin, carboxypeptidases
E. Aminopeptidases, elastase
769.
For effective formation of urea in the liver with great intensivity must proceed
ornithinic cycle. In the other case the concentration of ammonia in blood grows rapidly.
By the lack of what amino acid in the food can evolve azotemia?
A. * Arginine
B. Alanine
C. Lysine
D. Serine
E. Methionine
770.
GABA (gamma aminobutyric acid), which belongs to inhibiting mediators of
central nervous system, is a product of glutamic decarboxylation. What vitamin
prescription is appropriate by convulsive state, caused by decrease if GABA formation?
A. B1
B.
C.
D.
E.
B9
* B6
B5
B2
771.
glucogenic amino acid?
A. Acetyl-CoA
B. Malonil-CoA
C. * Pyruvate
D. Acetoacetyl-CoA
E. All of the above
772.
Higher plants most often absorb nitrogen from the soil in the form of
A. N2
B. Nitrites.
C. Ammonia.
D. * Nitrates.
E. Amino acids.
773.
Hydroxylation of phenylalanine requires all of the following except
A. * Phenylalanine hydroxylase
B. Tetrahydrobiopterin
C. NADH
D. Molecular oxygen
E. FAD
774.
Into the hospital was carried 7 years old child in the state of allergic shock, which
evolved after wasp's bite. In the blood increased concentration of histamine. This amine
is formed as a result of reaction of:
A. Dehydration
B. Deamination
C. Reduction
D. * Decarboxylation
E. Hydrooxidation
775.
Isoelectric pH of an amino acid is that pH at which it has a
A. Positive charge
B. Negative charge
C. * No charge
D. None of these
E. All of the above
776.
Kwashiorkor occurs when the diet is severely deficient in
A. Iron
B. Calories
C. * Proteins
D. Essential fatty acids
E. Ca++
777.
Maple syrup urine diseases is an inborn error of metabolism of
A. Sulphur-containing amino acids
B. Aromatic amino acids
C. * Branched chain amino acids
D. Dicarboxylic amino acids
E. None of the above
778.
Name the matter in the urine, which is a test of intensivity of protein putrefaction
processes in the intestine:
A. Urates
B. Urea
C. Creatinine
D. * Indican
E. Lactic acid
779.
Negative nitrogenous balance is observed in all listed cases, but:
A. Kidney disease
B. Domination of animal proteins in food
C. Domination of vegetable proteins in food
D. * In old years
E. By pancreatitis
780.
Nitrogen gas accounts for what percentage of the atmosphere?
A. 1%
B. * 7%
C. 55%
D. 78%
E. 99%
781.
Nitrogen is essential for living organisms to make:
A. Lipids.
B. * Proteins.
C. Carbohydrates.
D. Sulfates.
E. Benzene rings.
782.
Observation of 45-years old man, who was on vegetarian diet for a long time,
showed negative nitric balance. What food allowance feature caused this event?
A. Excessive amount of carbohydrates
B. * Insufficient amount of proteins
C. Excessive amount of water
D. Insufficient amount of fats and proteins
E. Insufficient amount of fats
783.
One of the following amino acid is solely ketogenic:
A. * Lysine
B. Alanine
C. Valine
D. Glutamate
E. Arginine
784.
Pancreatic juice contains the precursors of all of the following except
A. * Trypsin
B. Chymotrypsin
C. Carboxypeptidase
D. Aminopeptidase
E. Elastase
785.
Patient has positive nitric balance. The reason of this can be:
A. Starvation
B. Tuberculosis
C. * Pregnancy
D. Malignant neoplasms
E. AIDS
786.
Patient has the diagnosis “malignant carcinoid”, amount of serotonine in blood
increased greatly. Name amino acid, able to form the given biogenic amine:
A. Alanine
B. * 5-oxytryptophane
C. Leucine
D. Threonine
E. Methionine
787.
Patient on a vegetarian diet has negative nitric balance, hyperproteinemia,
affection of colloid-osmotic pressure and water-salt metabolism by normal function of
alimentary canal. This was caused by:
A. * Monotonous protein nutrition
B. Monotonous carbohydrate nutrition
C. Lack of unsaturated fatty acids
D. Lack of phospholipids in food
E. Lack of vitamins in food
788.
Serines are all names of families of what?
A. Carbohydrates
B. Fats
C. * Amino acids
D. Pyridines
E. Vitamins
789.
Sulphur-containing amino acid is
A. Glutathione
B. Chondroitin sulphate
C. * Homocysteine
D. Tryptophan
E. Histidin
790.
The amount of urea in the patient's blood is 16 mmol/l, in daily urine 6 g. The
possible reason for this is the following:
A. Liver disease
B. Starvation
C. * Kidney disease
D. Acidosis
E. Thyrotoxicosis
791.
The defective enzyme in histidinemia is
A. Histidine carboxylase
B. Histidine decarboxylase
C. * Histidase
D. Histidine oxidase
E. None of the above
792.
The process where some bacteria remove nitrate from the soil by converting it to
nitrogen gas is:
A. Nitrification.
B. Ammonification.
C. Assimilation.
D. * Denitrification.
E. Nitrogen fixation.
793.
The reservoir for nitrogen is
A. The atmosphere.
B. Rocks.
C. Ammonia.
D. * Nitrates.
E. Amino acids.
794.
The ruminant obtains nitrogen primarily from
A. * Plant protein
B. The microbes of the gastrointestinal tract
C. Urea
D. Fatty acids produced in the rumen.
E. Carbohydrates
795.
The step in the nitrogen cycle where bacteria convert ammonia (NH3) to nitrate
(NO3-) is:
A. * Nitrification.
B. Ammonification.
C. Assimilation.
D. Denitrification.
E. Nitrogen fixation.
796.
The toxicity of ammonia, especially dangerous for brain, is connected with its'
ability to affect functioning of tricarboxylic acids cycle in mitichondria of brain neurons
as a result of conclusion from the cycle of:
A.
B. Citrate
C. Malate
D. Succinate
E. * Fumarate
797.
The useful reagent for detection of amino acids is
A. Molisch reagent
B. Dichlorophenol Indophenol
C. * Ninhydrin
D. Biuret
E. None of the above
798.
To endopeptidases belong all below-mentioned ferments, but:
A. Pepsin
B. Elastase
C. * Carboxypeptidase
D. Chemotrypsin
E. Trypsin
799.
What is the first step in the nitrogen cycle, in which gaseous nitrogen is converted
into ammonia?
A. * Nitrification
B. Ammonification
C. Assimilation
D. Denitrification
E. Nitrogen fixation
800.
What is the main transportation form of ammonia from the majority of peripheral
tissues to the liver?
A. Urea
B. Aminosuccinamic
C. Citrulline
D. Ornithine
E. * Glutamine
801.
What is/are true regarding the urea cycle?
A. It plays an important role in nitrogen metabolism
B. It has a role in both the catabolism and anabolism of amino acids
C. * It is linked to the citric acid cycle
D. All of the above
E. None of the above
802.
What major way of ammonia deactivation, which formed in the organism as a
result of deamination reactions?
A. Glutamine synthesis
B. Ammonium salts synthesis
C. * Urea synthesis
D. Uric acid synthesis
E. Aminosuccinamic synthesis
803.
What part of the nitrogen cycle deals with the conversion of nitrogen in waste
products or dead organisms into ammonia?
A. Nitrification
B. * Ammonification
C. Assimilation
D. Denitrification
E. Nitrogen fixation
804.
Which amino acid is a lipotropic factor?
A. Lysine
B. Lecuine
C. Tryptophan
D. * Methionine
E. Valine
805.
Which of the following contributes nitrogen atoms to both purine and pyrimidine
rings?
A. * Aspartate
B. Carbamoyl phosphate
C. CO2
D. Glutamine
E. Fumarate
806.
Which of the following molecules will be formed from the carbon skeleton of a
ketogenic amino acid?
A. * Acetyl-CoA
B. Oxaloacetate
C. Pyruvate
D. Alfa-ketoglutarate
E. All of the above
807.
Which of the following protein is rich in cysteine?
A. Elastine
B. * Collagen
C. Fibrin
D. Keratin
E. None of the above
808.
Which of the following statements is (are) correct regarding nitrogen pollution?
A. Fresh water bodies are more often nitrogen limited than salt water bodies
B. Dissolved ammonia gas can be directly toxic to fish
C. In an undisturbed forest, nitrogen losses per year are generally less than the
amount of nitrogen contributed from the atmosphere.
D. In temperate regions, the greatest potential for leaching of nitrate occurs during
the fall and winter, when evapotranspiration is low relative to precipitation
E. * Answers 2, 3, and 4 above are all correct
809.
Which of the following statements is correct?
A. The two nitrogen atoms that are incorporated into urea enter the cycle as ammonia
and alanine.
B. Urea is produced directly by the hydrolysis of ornithine.
C. ATP is required for the reaction in which argininosuccinate is cleaved to form
arginine.
D. The urea cycle occurs exclusively in the cytosol.
E. * In humans, the major route of nitrogen metabolism from amino acids to urea is
catalyzed by the combined actions of transaminase (aminotransferase) and
glutamate dehydrogenase.
810.
Which of the following would most likely act as an inhibitor of the enzymes of the
citric acid cycle?
A. * A high concentration of ADP
B. A high concentration of ATP
C. A low concentration of NADH
D. A high concentration of NAD
E. More than one of the above.
811.
Which one of the following is an essential amino acid?
A. Arginine
B. Tyrosine
C. * Phenylalanine
D. Proline
E. Ornitine
812.
Why is nitrapyrin (2-chloro-6-trichloromethylpyridine) added to ammonia
fertilizers?
A. To convert the ammonia to nitrate which is the preferred nitrogen source for
plants.
B. * To solubilize the ammonia.
C. To inhibit nitrifying bacteria that convert ammonia to nitrite.
D. To inhibit assimilatory nitrate reduction.
E. None of the above
Test questions for figures
1. Coenzyme S-adenosylmethionine, shown in figure 52, participates in many reactions of
biosynthesis as a donator of:
A. Phosphoryl group
B. Acetyl group
C. Hydroxyl group
D. * Methyl group
E. Carboxyl group
2. Compound shown in figure 53 is a metabolite coenzyme which can donate phosphoryl
group in biochemical reactions. This compound is:
A. NADH
B. FADH2
C. TPP
D. * ATP
E. HS-CoA
3. Compound shown in figure 54 is the coenzyme for oxido-reductases. This is:
A. * NADH
B. FADH2
C. TPP
D. ATP
E. HS-CoA
4. Compound shown in figure 55 is the coenzyme for oxido-reductases. This is:
A. NADH
B. * FADH2
C. TPP
D. ATP
E. HS-CoA
5. Compound shown in figure 56 is the coenzyme for pyruvate dehydrogenase and
transketolase. This is:
A. NADH
B. FADH2
C. * TPP
D. ATP
E. HS-CoA
6. Electrons flow through the ETC components shown in figure 76 spontaneously in the
direction of increasing redox potentials. What is the reduction potential of the component
replaced with digit 5?
A. -0.32
B. -0.82
C. * +0.82
D. 0.00
E. +0.32
7. Equation shown in the figure 68 represents:
A. * Theory of intermediate enzyme-substrate complex
B. Induced-fit theory of enzyme and substrate
C. Lock-and-key theory of enzyme and substrate
D. Koshland theory
E. Fisher theory
8. ETC consists of several complexes. What is the name of complex shown in figure 77?
A. * Complex I (NADH-ubiquinone oxidoreductase)
B. Complex II (succinate-ubiquinone oxidoreductase)
C. Complex III (ubiquinone-cytochrome c oxidoreductase)
D. Complex IV (cytochrome c oxidase)
E. Complex V (NADH-cytochrome c oxidoreductase)
9. ETC consists of several complexes. What is the name of complex shown in figure 78?
A. Complex I (NADH-ubiquinone oxidoreductase)
B. * Complex II (succinate-ubiquinone oxidoreductase)
C. Complex III (ubiquinone-cytochrome c oxidoreductase)
D. Complex IV (cytochrome c oxidase)
E. Complex V (NADH-cytochrome c oxidoreductase)
10. ETC consists of several complexes. What is the name of complex shown in figure 79?
A. Complex I (NADH-ubiquinone oxidoreductase)
B. Complex II (succinate-ubiquinone oxidoreductase)
C. * Complex III (ubiquinone-cytochrome c oxidoreductase)
D. Complex IV (cytochrome c oxidase)
E. Complex V (NADH-cytochrome c oxidoreductase)
11. ETC consists of several complexes. What is the name of complex shown in figure 80?
A. Complex I (NADH-ubiquinone oxidoreductase)
B. Complex II (succinate-ubiquinone oxidoreductase)
C. Complex III (ubiquinone-cytochrome c oxidoreductase)
D. * Complex IV (cytochrome c oxidase)
E. Complex V (NADH-cytochrome c oxidoreductase)
12. Formulate the phenomenon shown in figure 81.
A. The pumping of protons into the intermembrane space results in the electrons
flow through complexes of ETC.
B. * As electrons flow through complexes of ETC, protons are translocated from
matrix into the intermembrane space.
C. Electron transport through complexes of ETC is inhibited by ATP synthesis.
D. Electron transport and ATP synthesis are coupled by a OH- gradient across the
inner mitochondrial membrane.
E. The pumping of protons into the matrix results in the electrons flow through
complexes of ETC.
13. How many protons are pumped out of the matrix when two electrons flow through the
ETC complex shown in the figure 77?
A. 1
B. 2
C. 3
D. * 4
E. 5
14. How many protons are pumped out of the matrix when two electrons flow through the
ETC complex shown in the figure 78?
A. 1
B. 2
C. 3
D. 4
E. * 0
15. How many protons are pumped out of the matrix when two electrons flow through the
ETC complex shown in the figure 79?
A. 1
B. 2
C. 3
D. * 4
E. 0
16. How many protons are pumped out of the matrix when two electrons flow through the
ETC complex shown in the figure 80?
A. 1
B. * 2
C. 3
D. 4
E. 0
17. How many protons are pumped out of the matrix when two electrons flow through the
ETC shown in the figure 80?
A. * 10
B. 3
C. 4
D. 15
E. 0
18. In electron transport chain shown in figure 76 some components are missing. Which
carrier is replaced with digit 1?
A. * FMN
B. FAD
C. CoQ
D. Cytochrom c
E. Fe-S clusters
19. In electron transport chain shown in figure 76 some components are missing. Which
carrier is replaced with digit 3?
A. FMN
B. FAD
C. * CoQ
D. Cytochrom c
E. Fe-S clusters
20. In electron transport chain shown in figure 76 some components are missing. Which
carrier is replaced with digit 4?
A. FMN
B. FAD
C. CoQ
D. * Cytochrom c
E. Fe-S clusters
21. In electron transport chain shown in figure 76 some components are missing. Which
component is replaced with digit 5?
A. FMN
B. FAD
C. * O2
D. Cytochrom c
E. Fe-S clusters
22. In electron transport chain shown in figure 79 some components are missing. Which
carrier is replaced with digit 2?
A. FMN
B. * FAD
C. CoQ
D. Cytochrom c
E. Fe-S clusters
23. In figure 61 the example of reaction is shown.
A. Oxidation-reduction
B. Hydrolysis
C. * Group transfer
D. Synthesis
E. Isomerization
24. In figure 62 the example of reaction is shown.
A. Oxidation-reduction
B. * Hydrolysis
C. Group transfer
D. Synthesis
E. Isomerization
25. In figure 63 the example of reaction is shown.
A. Oxidation-reduction
B. Hydrolysis
C. Group transfer
D. * Lysis of substrate
E. Isomerization
26. In figure 64 the example of reaction is shown.
A. Oxidation-reduction
B. Hydrolysis
C. Group transfer
D. Lysis of substrate
E. * Isomerization
27. In figure 65 the example of reaction is shown.
A. Oxidation-reduction
B. Hydrolysis
C. Group transfer
D. * Ligation
E. Isomerization
28. In the figure 71 activator binds noncovalently to specific site and regulate enzyme
activity via conformational changes. This activator can be also called:
A. * Allosteric modulator
B. Covalent modulator
C. Proteolytic factor
D. Negative modulator
E. Covalent factor
29. In the figure 72 the reaction of covalent modification of enzyme is shown. Such
modification is called:
A. Acetylation
B. Methylation
C. Sulfation
D. Carboxylation
E. * Phosphorylation
30. In the figure 73 the scheme of enzyme is shown.
A. Allosteric regulation
B. * Covalent modification
C. Proteolytic cleavage
D. Negative feedback regulation
E. Positive feedback regulation
31. In the figure 74 the scheme of enzyme regulation is presented. Such mechanism is called:
A. * Feedback inhibition
B. Feedback activation
C. Proteolytic activation
D. Positive feedback
E. Allosteric regulation
32. In the figure 78 the reaction of enzyme is shown.
A. Allosteric regulation
B. Covalent modification
C. * Proteolytic cleavage
D. Negative feedback regulation
E. Positive feedback regulation
33. In which reactions in biological pathway shown in figure 92 NADH are formed?
A. 1, 3, 6
B. 4, 5, 8
C. 2, 4, 8
D. 3, 5, 7
E. * 2, 3, 7
34. Membrane of which organelle is shown in figure 81?
A. Nucleus
B. * Mitochondria
C. Endoplasmic reticulum
D. Cell membrane
E. Lysosome
35. NAD in the reaction shown in figure 60 plays the role of:
A. Donor of protons
B. Donor of electrons
C. Acceptor of proton
D. Acceptor of electrons
E. * Acceptor of protons and electrons
36. Name the enzyme catalyzing the reaction shown in figure 91.
A. Protein kinase
B. * Pyruvate dehydrogenase
C. Pyruvate carboxylase
D. Pyruvate corboxykinase
E. Acetyl CoA dehydrogenase
37. Name the enzyme which is replaced with question-mark in figure 89.
A. Dehydrogenase
B. * Protein kinase
C. Adenylatcyclase
D. ATP-ase
E. Aldolase
38. Name the product of reaction depicted in figure 91.
A. Citrate
B. * Acetyl CoA
C. Oxaloacetate
D. Phosphoenol pyruvate
E. Isocitrate
39. The complex enzyme is shown in the figure 49. The nonprotein part of this enzyme is
called:
A. Coenzyme
B. Cofactor
C. * Prosthetic group
D. Apoenzyme
E. Holoenzyme
40. The curve reflecting the enzyme activity vs pH is shown in figure 58. Which enzyme
most probably is it?
A. Amilase
B. Chemotrypsin
C. Trypsin
D. * Pepsin
E. Lipase
41. The curve shown in figure 66 is typical for description of:
A. The effect of temperature on enzyme activity
B. The effect of pH on enzyme activity
C. * The effect of substrate concentration on the rate of reaction
D. The effect of enzyme concentration on the rate of reaction
E. The effect of pH on the rate of reaction
42. The curve shown in figure 67 is typical for description of:
A. The effect of temperature on enzyme activity
B. The effect of pH on enzyme activity
C. The effect of substrate concentration on the rate of reaction
D. * The effect of enzyme concentration on the rate of reaction
E. The effect of pH on the rate of reaction
43. The enzyme catalyzing the oxidation-reduction reaction shown in figure 60 belong to the
following subclass:
A. Oxidases
B. Peroxidases
C. * Dehydrogenases
D. Peptidases
E. Esterases
44. The enzyme catalyzing the reaction of hydrolysis shown in figure 62 belong to the
following subclass:
A. * Phosphatases
B. Peroxidases
C. Dehydrogenases
D. Peptidases
E. Esterases
45. The enzyme shown in figure 49 can be characterized as:
A. Simple enzyme
B. * Metalloenzyme
C. Apoenzyme
D. Isoenzyme
E. Multifunctional enzyme
46. The following enzymes cannot function without the coenzyme shown in figure 54:
A. Peroxidases
B. Esterases
C. Glucosidases
D. * Dehydrogenases
E. Peptidases
47. The following enzymes cannot function without the coenzyme shown in figure 55:
A. Peroxidases
B. Esterases
C. Glucosidases
D. * Dehydrogenases
E. Peptidases
48. The following enzymes cannot function without the coenzyme shown in figure 56:
A. Peroxidase
B. Catalase
C. Glucosidase
D. * Pyruvate dehydrogenase
E. Peptidase
49. The formula shown in figure 68 is called:
A. * Michaelis-Menten equation
B. Krebs equation
C. Horbachevsky equation
D. Mitchell equation
E. Kori equation
50. The fragment of the enzyme structure is shown in the figure 49. Such enzyme can be
characterized as:
A. Simple enzyme
B. * Complex enzyme
C. Coenzyme
D. Isoenzyme
E. Multifunctional enzyme
51. The mechanism of active site-substrate interaction shown in figure 50 is called:
A. Induced-fit model
B. Chemiosmotic model
C. Allosteric model
D. * Lock and key model
E. Covalent binding model
52. The mechanism of active site-substrate interaction shown on figure 51 is called:
A. * Induced-fit model
B. Chemiosmotic model
C. Allosteric model
D. Lock and key model
E. Covalent binding model
53. The mechanism of enzyme activation presented in figure 75 is called:
A. Feedback activation
B. Positive activation
C. * Proteolytic activation
D. Covalent activation
E. Allosteric activation
54. The precursor for coenzyme FADH2 shown in figure 7 is:
A. Thiamin
B. * Riboflavin
C. Lipoic acid
D. Pyridoxine
E. Nicotinamide
55. The precursor for coenzyme NAD shown in figure 54 is:
A. Thiamin
B. Riboflavin
C. Lipoic acid
D. Pyridoxine
E. * Nicotinamide
56. The precursor for coenzyme NAD shown in figure 9 is:
A. Thiamin
B. Riboflavin
C. Lipoic acid
D. Pyridoxine
E. * Nicotinamide
57. The process of electron transferring via the factors shown in figure 76 is called:
A. Oxidative respiration
B. Oxidative phosphorylation
C. Substrate-level phosphorylation
D. * Tissue respiration
E. Substrate-level oxidation
58. The scheme of stages of catabolism is shown in figure 90. What compound is replaced
with the digit 1?
A. * Glucose
B. Pyruvate
C. Acetyl CoA
D. Citrate
E. NADH
59. The scheme of stages of catabolism is shown in figure 90. What compound is replaced
with the digit 2?
A. Glucose
B. Pyruvate
C. * Acetyl CoA
D. Citrate
E. NADH
60. The sequence of components shown in figure 76 is called:
A. * Electron transport chain
B. Proton transport chain
C. NADH transport chain
D. NADH-O2 oxido-reductase
E. Proton ATP-ase
61. The typical curve reflecting the enzyme activity vs pH is shown in figure 57. Which
value of pH the question-mark corresponds to?
A. 5
B. 6
C. * 7
D. 8
E. 9
62. The typical curve reflecting the enzyme activity vs temperature is shown in figure 59.
Which value of temperature does the question-mark correspond to?
A. 27
B. 31
C. * 37
D. 42
E. 47
63. What biochemical pathway is shown in figure 92?
A. Glycolysis
B. Gluconeogenesis
C. Pentose phosphate pathway
D. * Citric acid cycle
E. Glycogenolysis
64. What compound is replaced with question-mark in figure 83?
A. ATP
B. * H3PO4
C. AMP
D. Pyruvate
E. Lactate
65. What enzyme catalyzes the reaction #1 in biological pathway depicted in figure 92?
A. Citrate synthase
B. * Aconitase
C. Isocitrate dehydrogenase
D. Alpha-ketoglutarate dehydrigenase
E. Succinyl CoA synthase
66. What enzyme catalyzes the reaction #4 in biological pathway depicted in figure 92?
A. Citrate synthase
B. Aconitase
C. Isocitrate dehydrogenase
D. Alpha-ketoglutarate dehydrigenase
E. * Succinyl CoA synthase
67. What enzyme catalyzes the reaction #5 in biological pathway depicted in figure 92?
A. Succinyl CoA synthase
B. * Succinate dehydrogenase
C. Fumarase
D. Malate dehydrogenase
E. Citrate synthase
68. What enzyme catalyzes the reaction #6 in biological pathway depicted in figure 92?
A. Succinyl CoA synthase
B. Succinate dehydrogenase
C. * Fumarase
D. Malate dehydrogenase
E. Citrate synthase
69. What enzyme catalyzes the reaction #7 in biological pathway depicted in figure 92?
A. Succinyl CoA synthase
B. Succinate dehydrogenase
C. Fumarase
D. * Malate dehydrogenase
E. Citrate synthase
70. What enzyme catalyzes the reaction 8 in biological pathway depicted in figure 92?
A. Succinyl CoA synthase
B. Succinate dehydrogenase
C. Fumarase
D. Malate dehydrogenase
E. * Citrate synthase
71. What enzyme catalyzes the reaction № 3 in biological pathway depicted in figure 92?
A. Citrate synthase
B. Aconitase
C. Isocitrate dehydrogenase
D. * Alpha-ketoglutarate dehydrogenase
E. Succinyl CoA synthase
72. What principle of enzyme regulation is shown in figure 87?
A. * Feedback inhibition
B. Feed-forward activation
C. Feed-forward inhibition
D. Feedback activation
E. None of the above
73. What principle of enzyme regulation is shown in figure 78?
A. Feedback inhibition
B. * Proteolytic activation
C. Feed-forward inhibition
D. Feedback activation
E. None of the above
74. What product is shown in figure 82?
A. * acetil Co A
B. H3PO4
C. AMP
D. Pyruvate
E. Lactate
75. What reaction is shown in figure 91?
A. Reduction of pyruvate
B. Oxidation of acetyl CoA
C. Entering of acetyl CoA into tricarboxylic acid cycle
D. * Oxidative decarboxylation of pyruvate
E. Oxidative reduction of pyruvate
76. What theory describes the scheme shown in figure 81?
A. Key-and-lock theory
B. Fit-induced theory
C. * Chemiosmotic theory
D. Enzyme-substrate complex theory
E. Koshland theory
77. What theory of active site-substrate interaction is presented in the figure 50?
A. * Fischer theory
B. Coshland theory
C. Horbachevky theory
D. Mitchell theory
E. Krebs theory
78. What theory of active site-substrate interaction is presented on the figure 51?
A. Fischer theory
B. * Coshland theory
C. Horbachevky theory
D. Mitchell theory
E. Krebs theory
79. What type of enzyme regulation is shown in figure 71?
A. Covalent modification
B. Uncompetitive
C. Competitive
D. * Allosteric
E. Proteolytic
80. What type of inhibition is shown in figure 69?
A. Noncompetitive
B. Uncompetitive
C. * Competitive
D. Allosteric
E. Proteolytic
81. What type of inhibition is shown in figure 70?
A. * Noncompetitive
B. Uncompetitive
C. Competitive
D. Allosteric
E. Proteolytic
82. What type of metabolic pathway is depicted in the figures 84?
A. * Linear
B. Cyclic
C. Spiral
D. Dichotomic
E. None of the above
83. What type of metabolic pathway is depicted in the figures 85?
A. Linear
B. * Cyclic
C. Spiral
D. Dichotomic
E. None of the above
84. What type of metabolic pathway is depicted in the figures 86?
A. Linear
B. Cyclic
C. * Spiral
D. Dichotomic
E. None of the above
85. Where does reaction depicted in figure 91 take place?
A. In cytoplasm
B. In nucleus
C. In endoplasmic reticulum
D. * In matrix of mitochondria
E. In lysosomes
86. Which class does the enzyme catalyzing the reaction shown in figure 61 belong to?
A. Oxido-reductases
B. * Transferases
C. Hydrolases
D. Lyases
E. Ligases
87. Which class does the enzyme catalyzing the reaction shown in figure 62 belong to?
A. Oxido-reductases
B. Transferases
C. * Hydrolases
D. Lyases
E. Ligases
88. Which class does the enzyme catalyzing the reaction shown in figure 68 belong to?
A. * Oxido-reductases
B. Transferases
C. Hydrolases
D. Lyases
E. Ligases
89. Which class does the enzyme catalyzing the reaction shown in figure 64 belong to?
A. Oxido-reductases
B. Transferases
C. Hydrolases
D. Lyases
E. * Isomerases
90. Which class does the enzyme catalyzing the reaction shown in figure 65 belong to?
A. Oxido-reductases
B. Transferases
C. Hydrolases
D. Lyases
E. * Ligases
91. Which class does the enzyme catalyzing the reaction shown in figure 60 belong to?
A. * Oxido-reductases
B. Transferases
C. Hydrolases
D. Lyases
E. Ligases