2013 Block 1 Unit 2 Practice Questions
Written/Compiled by John Luckoski
Many thanks are due to Shane Sheahan, Kevin Carbone, and Dan Feldman for writing the majority of these questions. Also, I
highly suggest looking at the formative questions written by the professors that are on blackboard.
This is all student-made, and thus prone to error. If you find any mistakes make it known! I wish you all way more than luck.
AND DON'T FORGET ABOUT THE SELF STUDY!!!
Carbohydrates:
1.
This disaccharide is the primary sugar component in milk. What are the component
monosaccharides that make up this disaccharide?
a.
b.
c.
d.
e.
α-Mannose & β-Glucose
α-Glucose & α-Galactose
α-Galactose & β-Glucose
β-Galactose & β-Glucose
β-Galactose & α-Glucose
Use the figures to answer the following questions 2-4:
A
B
2. The above sugars are monosaccharides. These sugars are involved in numerous biological
reactions and components in disaccharides. How are these monosaccharides different?
a. A is a Pentose and B is a Hexose
b. A is a Ketose and B is an Aldose
c. A is an Aldose and B is a Ketose
d. A can be used as a source of energy and B can not
e. A is a component of Sucrose and B is a component of Lactose
3. Switching the hydrogen and hydroxyl group of the α-D-Glucose above at the anomeric
carbon will result in what compound?
a. α-D-Galactose
b. α-D- Mannose
c. β-D-Glucose
d. β-D-Galactose
e. β-D-Mannose
2
4. An epimerization at the 4th carbon only of α-D-Glucose will result in what compound?
a. α-D-Galactose
b. α-D- Mannose
c. β-D-Glucose
d. β-D-Galactose
e. β-D-Mannose
5. A diabetic patient claims to be controlling his blood glucose levels very well, but you have
your doubts. You order an HbA1c test to ensure your patient has been on top things. You recall
that the test measures the amount of glucose attached to hemoglobin, but are struggling to
remember what process occurs to bond the two together. After researching you find that
glycosylated hemoglobin is the result of:
a. a Schiff Base Reaction followed by an Amadori rearrangement
b. an Ester formation plus a hydrolysis of the second monosaccharide
c. a beta oxidation reaction and a thiolysis
d. a dehydration reaction after hemolysis
e. a glycoside formation using a H+ catalyst
6. Consider the following sugars: Glucose, fructose, xyulose, galactose, ribose, mannose.
How many of these sugars are ketoses?
a. 1
b. 2
c. 3
d. 4
e. 5
7. Trehalose is a disaccharide formed by the combination of which two monosaccharides, and
at what specific carbon configuration?
a. β -glucose and β -glucose at carbons 1 and 4
b. α-glucose and β-fructose at carbons 1 and 2
c. α-glucose and α-glucose at carbons 1 and 4
d. α-glucose and α-glucose at carbons 1 and 1
e. β –glucose and β –galactose at carbons 1 and 4
8. What kind of linkages does glycogen contain?
a. alpha 1:4 & beta 1:6
b. alpha 1:4 & alpha 1:6
c. beta 1:4 & beta 1:6
d. beta 1:6 & beta 1:4
e. none of the above
3
Glycolysis:
9. Which of the following enzymes does not catalyze an irreversible step in glycolysis?
a. Hexokinase
b. Phosphofructokinase
c. Pyruvate carboxylase
d. Pyruvate Kinase
e. None of the above
10. How many net moles of ATP are produced during glycolysis of 1 mol of glucose in the
presence of oxygen?
a. 0
b. 2
c. 4
d. 10
e. 32
11. Which of these enzymes catalyzes a reversible step of glycolysis?
a. Hexokinase
b. Phosphofructokinase
c. Phosphohexose isomerase
d. Pyruvate kinase
e. None of these
12. After a meal, glucose levels in the body are very high. As a result the TCA cycle is
running at full force, producing lots of citrate, resulting in lots of ATP production by the
electron transport chain. This result would…
a. Reduce the rate of glycolysis
b. Increase the rate of glycolysis
c. Decreased ATP production by glycolysis
d. Increase in lactic acid levels
e. would have no effect on glycolysis
13. A cell takes in 16 molecules of glucose. How many total ATP are produced solely by
glycolysis in this situation?
a. 16
b. 32
c. 64
d. 112
e. 144
4
14. Your friend is a body builder, who has decided to go out for a night on the town to drink as
much alcohol as he can to celebrate his intense workout. You explain to him that this might not
be a good idea. Why would you tell him this?
a. The alcohol will cause a depletion of NAD+ resulting in lack of inhibition on the TCA
cycle
b. Alcohol consumption in his state can result in hyperglycemia
c. The breakdown of Alcohol will deplete NADH causing lethargy
d. Alcohol consumption after a strenuous workout can cause lactic acidosis
e. Alcohol is an elixir of the devil and its consumption is the first step of a ritualistic pact
to devote your soul to his evil works. Not to mention hang overs.
15. Which glycolysis enzymes are directly inhibited by ATP?
a. Phosphoglycerate kinase
b. Phosphofructokinase
c. Pyruvate kinase
d. A + C
e. B + C
16. In the glycerol phosphate shuttle, which two glycolysis intermediates are involved with an
oxidation via FAD+, and what is the direction of the reaction?
a. dihydroxyacetone phosphate to α-ketoglutarate
b. Glycerol-3-phosphate to dihydroxyacetone phosphate
c. dihydroxyacetone phosphate to glycerol-3-phosphate
d. α-ketoglutarate to dihydroxyacetone phosphate
e. glyceraldehyde-3-P to pyruvate
17. Within the Malate Aspartate shuttle, aspartate aminotransferase acts upon aspartate to
form which amino acid?
a. Malate
b. Glutamate
c. Glutamine
d. α-ketoglutarate
e. Oxaloacetate
5
BONUS ROUND!!!! Fill out the glycolysis chart. Super extra double bonus points for putting the
enzymes in proper order! (You will want to be able to do this for the real exam!)
6
Lipids - Beta-Oxidation and Fatty Acid Synthesis:
18. Which of these contains an isoprene component?
a. Sphingolipid
b. Sterol
c. Acylglycerol
d. Eicosanoid
e. Phospholipid
19. The enzyme that catalyzes the acylation of Coenzyme A is a
a. Thiokinase
b. Thiolase
c. Dehydrogenase
d. Hydratase
e. None of the above
20. What enzyme catalyzes the conversion of diacylglycerol to triacylglycerol in triacylglycerol
biosynthesis?
a. Phosphatidate Phosphatase
b. Diglyceride Acyltransferase
c. Glycerol-3-Phosphate Acyltransferase
d. 1-Acyl-Glycerol-3-Phosphate Acyltransferase
e. Thiolase
21. Which class of Eicosanoids plays a role in decreasing platelet aggregation?
a. Thromboxanes
b. Leukotrienes
c. Prostacyclins
d. Both B and C
e. All of the above
22. Which of these is the correct sequence of intermediates in the cholesterol synthesis
pathway in mammalian cells?
a. Isopentyl-PP, Farnesyl-PP, Geranyl-PP, Squalene, Cholesterol
b. Mevalonate, Isopentyl-PP, Squalene, Farnesyl-PP, Cholesterol
c. Geranyl-PP, Farnesyl-PP, Isopentyl-PP, Squalene, Cholesterol
d. Mevalonate, Isopentyl-PP, Farnesyl-PP, Geranyl-PP, Squalene
e. Isopentyl-PP, Geranyl-PP, Farnesyl-PP, Squalene, Cholesterol
7
23. How many ATP are produced when one molecule of Myristate is broken down (Recall that it
must be activated before being broken down)?
a. 94
b. 92
c. 120
d. 106
e. 122
24. In β-Oxidation within the mitochondria ______ is the electron acceptor where as in β
oxidation within peroxisomes _____ is the electron acceptor.
a. NAD+, O2
b. NAD+, H2O2
c. NAD+/FAD, O2
d. NAD+/FAD, H2O2
25. How many rounds of Fatty Acid synthesis does it take to construct Myristate?
a. 9
b. 8
c. 7
d. 6
26.Which of these fatty acids can be synthesized by mammalian cells, and therefore does not
need to be consumed in the diet? Hint: Adrenate is denoted by 22:4 (7,10,13,16).
a. Linoleate
b. Linolenate
c. Arachidonate
d. Stearate
e. Adrenate
27. A mother brings her 5 year old child into your clinic because she feels something is wrong.
The child explains he has been really fatigued lately and upon examination, you notice his liver
is enlarged. A simple blood test reveals he is anemic, but you order another test to measure
the level of glucocerebrosidase activity. It turns out it is deficient, which means his tissues are
accumulating glucocerebroside. The medical student shadowing you that day explains she
remembers learning about a disease where this occurs. What disease would she have
mentioned:
a. Gaucher’s Disease type 1
b. Gaucher’s Disease type 2
c. Niemann-Pick Disease
d. Tay-Sachs Disease
e. Fabry’s Disease
8
28. All of the following are true EXCEPT:
a. Sphingosine is derived from palmityl-CoA and aspartate
b. Adding one sugar to a ceramide creates a cerebroside
c. Adding at least one sugar to a cerebroside creates gangliosides or globosides
d. Spingolipids can be phospholipids or glycolipids
e. None of the above
29. Phosphatidic acid is the result of what enzyme acting on phosphoglycerides:
a. Phospholipase A1
b. Phospholipase A2
c. Phospholipase C
d. Phospholipase D
e. None of the above
30. Choose the correct statement about Eicosanoids:
a. All of them are created by cleaving arachidonate with prostaglandin synthase
b. Thromboxanes cause vasodilation and prevent platelet aggregation
c. Singulair will block the receptors for leukotrienes
d. Both A and B
e. All of the above
31. All of the following are characteristics of Acetaminophen EXCEPT:
a. Inhibits prostaglandin H2 synthase reversibly
b. It can reduce fever
c. Reduces inflammation and prevents platelet aggregation in the periphery
d. Both A and C
e. None of the above
32. Choose the correct statement about bile salts:
a. They are polar derivatives of cholesterol
b. They are produced in the liver and stored in the gall bladder
c. Questran is used to increase the absorption from the gut
d. Only A and B
e. All of the above
33. All of the following are true regarding HMG-CoA reductase EXCEPT:
a. It catalyzes a reaction that takes place in the cytoplasm
b. Statin drugs are noncompetitive inhibitors of the enzyme
c. It is stimulated by the uptake of LDL cholesterol
d. It is inhibited by a decrease of cholesterol in the cell
e. All of the above are false regarding HMG-CoA reductase
9
34. Choose the correct statement regarding the conversion of cholesterol to steroid hormones:
a. 21-hydroxylase must add an –OH before 17-hydroxylase when going from
progesterone to cortisol
b. Aldosterone can be created from cortisol using 18-hydroxylase
c. Aromatase is used to create estrone and estradiol from androstenedione and
testosterone
d. Testosterone can be created from estrone or estradiol
e. All of the above
35. Which of the following regarding P450 monooxygenases is FALSE:
a. They are located in smooth ER of the liver and small intestine, mainly
b. The duration of many drugs depends on the rate of inactivation by the hepatic P450
system
c. They function in detoxification of drugs such as Ibuprofen
d. Only A and C
e. None of the above are false
36. 21-Hydroxylase deficiency:
a. Is the rarest inherited disorder of steroid hormone synthesis
b. Can cause adrenal hyperplasia and hypotension
c. Is treated using immunosuppressants
d. Is the enzyme required for the synthesis of androgens
e. Both A and B
37. There is a defect in the production of NADPH by the Pentose phosphate pathway due to a
mutation the first enzyme in this step. If fatty acid synthesis were to be conducted which
enzyme would produce the NADPH required for this synthesis?
a. Malate Dehydrogenase
b. Citrate Lyase
c. Malic enzyme
d. Glucose-6-phospahte Dehydrogenase
e. None of the above
38. After a meal insulin levels are high which signals muscle and adipose tissues to take up
glucose. This high insulin level also cause
a. High levels of phosphorylated Acetyl-CoA Carboxylase
b. High levels of Protein Phosphatase 2A
c. High levels of fatty acid synthesis
d. High levels of active AMP-dependent Kinase
e. A&D
f. B&C
10
39. During triacylglycerol synthesis, in the reaction that results in the formation of a
diacylglycerol, what is the most probable structural nature of the acyl group that is attached?
a. It is most likely unsaturated
b. It is most likely saturated
c. It is most likely an alcohol group, not an acyl group
d. It is equally likely to be saturated or unsaturated
e. It is most likely an acetyl group
40. What is the direct product of the HMG-CoA lyase reaction?
a. Mevalonic acid
b. Acetoacetate
c. Cholesterol
d. D-3-Hydroxybutyrate
e. Acetone
41. What happens to acetoacetate after it is formed?
a. It is utilized by the liver as an energy source
b. It is converted to acetoacetyl-CoA that can be used directly into the TCA cycle.
c. It is converted into acetoacetyl-CoA that uses thiolase to generate acetyl-CoA for use
in the TCA cycle
d. It is utilized by tissues other than the liver as an alternative energy source
e. Both C & D
42. Which of the following molecules determines the fate of acetyl-CoA between ketone body
formation and the TCA cycle in liver metabolism?
a. Alpha-ketoglutarate
b. Pyruvate
c. Oxaloacetate
d. All of the above
e. None of the above
43. What is the main function of dipalitoyl-phosphatidylcholine?
a. It is a signaling precursor for IP3 and DAG.
b. It is a major component of lung surfactant
c. It is commonly used in mitochondrial membranes
d. It is used for allergic hypersensitivity reactions
e. It is used for the synthesis of sphingosine
44. Which of the following ways is used to form phosphoglyceride?
a. Through an ADP-activated Diacylglycerol Intermediate
b. Through a CDP-activated Diacylglycerol Intermediate
c. Through an ADP-activated Alcohol Intermediate
d. Through a CDP-activated Alcohol Intermediate
e. Both B & D
11
45. What is the name of a glycolipid that has a neutral branched oligosaccharide chain
attached?
a. Cerebroside
b. Ganglioside
c. Globoside
d. Ceranude
e. Sulfatide
46. A young child is presenting signs of fatigue and is easily bruised. You run some tests and find
out that the fatigue is most likely due to the child being anemic. After further tests you see that
the patient’s liver and spleen are enlarged and they have a weak skeleton. There also seems to
be some impairment of the patient’s lung function. You know what disease this is, and you
know that it can be treated with some success with IV enzyme replacement therapy. What is
most likely the cause of these symptoms?
a. Type 1 Gaucher’s disease
b. Type 3 Gaucher’s disease
c. Niemann-Pick disease
d. Tay-Sachs disease
e. Fabry’s disease
47. For signaling purposes, which of the following phospholipases is responsible for cleaving
arachidonic acid from a phopholipid?
a.
b.
c.
d.
e.
Phospholipase A1
Phospholipase A2
Phospholipase B
Phospholipase C
Phospholipase D
48. Which of the following class of drugs is known to inhibit COX-2 and no other COX isozyme?
a.
b.
c.
d.
e.
Celebrex
Aspirin
Ibuprofen
Viagra
Acetominophen
49. In which of the following is isoprene used for synthesis?
a. Heme A
b. Ubiquinone
c. Dolichol
d. Cholesterol
e. All of the above
12
50. In cholesterol synthesis, which of the following is a major branch point into the synthesis of
many other compounds?
a. Squlene
b. Isopentenyl-PP
c. Geranyl-PP
d. Farnesyl-PP
e. Mevalonate
51. Which of the following enzymes is regulated mainly as a form of keeping cholesterol
homeostasis?
a. HMG-CoA lyase
b. Mevalonate Kinase
c. HMG-CoA reductase
d. Isomerase
e. None of the above
52. Bile acids are important for the emulsification of fats during digestion. Which of the
following is not a characteristic of bile acids?
a. Polar derivative of cholesterol
b. Produced in the liver and stored in the gall bladder
c. Reabsorbed by the ileum
d. Released into the jejunum
e. Facilitate digestion of lipids by lipases
53. An infant patient presents to you with enlarged adrenal glands as well as an increased
secretion of ACTH from the anterior pituitary gland. The patient is smaller than normal and is
very hypotensive. You realize that this patient most likely has a problem with 21-Hydroxylase.
Which of the following will be missing when you test the patient’s steroid levels in the blood?
a. Mineralcorticoids
b. Glucocorticoids
c. Androgens
d. Both A & B
e. Both B & C
54. What is the name of the enzyme responsible for creating estrone and estradiol from
androstenedione and testosterone?
a. Aromatase
b. 17-hydroxylase
c. Isomerase
d. 21-hydroxylase
e. Androgen dehydrogenase
13
Pentose Phosphate Pathway:
55. Which of the following statements about the pentose phosphate pathway is correct?
a. It generates 36 mol of ATP per mol of glucose consumed.
b. It generates 6 mol of CO2 for each mol of glucose consumed.
c. It is a reductive pathway that consumed NADH.
d. It is present in plants, but not in animals.
e. It provides the precursors for the synthesis of nucleotides.
56. The oxidation of 3 mol of glucose by the PPP 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.
57. A patient comes into the ER complaining of extreme tiredness and dizziness. When looking
at her record you notice that she has hemolytic anemia. What enzyme is most likely affected to
cause this disorder?
a. Transketolase
b. Transaldolase
c. Glucolactonase
d. Glucose-6-Phosphate Dehydrogenase
58. The pentose phosphate pathway can be used to form a compound that is important in the
synthesis of a number of molecules especially DNA and RNA. What molecule is this?
a. NADPH
b. Ribose
c. NADH
d. Fructose-6-phosphate
59. How many of the NADPH molecules necessary for the synthesis of palmitate come from the
pentose phosphate pathway?
a. 6
b. 8
c. 10
d. 12
e. 14
60. All are functions of the pentose phosphate pathway EXCEPT
a. Provide a source of NADPH for biosynthetic reactions
b. Produce Ribose
c. An alternate route to break down glucose
d. An alternate route to produce NADH for energy production
14
Interconversion of Hexoses:
61. A six month old is brought to the emergency room. The parents have been complaining that
when given formula the baby begins to cry, vomit, and have diarrhea about thirty minutes after
feeding. Upon further examination you notice that there is some clouding of the infant’s eyes
and that the infant is slow to respond to all types of stimuli. A defect in what enzyme could
result in these symptoms?
a. Uridine Diphosphogalatose-4-Epimerase
b. UDPG Pyrophosphorylase
c. Galatose-1-Phosphate Uridyl Transferase
d. Galatokinase
e. Hexokinase
62. Which sugar(s) can be converted into glucose?
a. Galactose
b. Mannose
c. Fructose
d. Ribose
e. A & B
f. A, B, & C
g. All of the above
63. What is the primary function of UDP-Glucoronic Acid?
a. Being a high energy intermediate to conjugate Glucoronic acid to other molecules
b. To become detoxified in the liver
c. To produce ascorbic acid
d. To create more sugars that can be broken down by the pentose phosphate pathway
Nucleotide Metabolism
64. Which of the following is the level of phosphorylation at which ribonucleotides are
converted to deoxyribonucleotides? What is the cofactor?
a. Monophosphate, adenoredoxin
b. Diphosphate, thioredoxin
c. Triphosphate, thioredoxin
d. Both C and D
65. How many phosphate monoester bonds and acid anhydride bonds are present in ADP?
a. 2 phosphate monoester, 1 acid anhydride bonds
b. 1 phosphate monoester, 2 acid anhydride bonds
c. 1 phosphate monoester, 1 acid anhydride bonds
d. 2 phosphate monoester, 2 acid anhydride bonds
e. 1 phosphate monoester, 0 acid anhydride bonds
15
66. Which of the following nucleotides allosterically inhibit ribonucleotide reductase at the
general activity site?
a. dATP
b. dTTP
c. dUTP
d. dGTP
e. dCTP
67. Upon introducing aminopterin into a cell culture, which steps of purine synthesis would be
affected?
a. Only the rate limiting step
b. The ring closing steps
c. Steps utilizing glutamine as an N-donor
d. Steps involving the enzyme formyl transferase
e. Steps requiring ATP
68. Upon introducing azaserine into a cell culture, which steps of purine synthesis would be
affected?
a. Only the rate limiting step
b. The ring closing steps
c. Steps utilizing glutamine as an N-donor
d. Steps involving the enzyme formyl transferase
e. Steps requiring ATP
69. Which of the following is the first pyrimidine nucleotide that is formed during de novo
pyrimidine biosynthesis?
a. AMP
b. CMP
c. UMP
d. OMP
e. TMP
70. Orotic acid and Inosine monophosphate have which of the following in common?
a. Both have a ribose group attached following their synthesis
b. Both are purines
c. Both are pyrimidines
d. Both undergo a dehydrogenation in the step before their synthesis
e. Both are the first representative base (purine or pyrimidine) prior to creating the
desired product
16
71. Which of the following enzyme is regulated early in the de novo pyrimidine biosynthesis by
UTP?
a. Carbamoyl Phophate Synthetase
b. Asparatate Transcarbamoylase
c. Dehydroorotase
d. Dihidroorotate dehydrogenase
72. Which of the following bases can be converted back to nucleotides by using phosphoribosyl
transferase as one of the salvage pathway?
a. Adenine, Cytosine, and Guanine
b. Adenine, Guanine, and Uracil
c. Uracil and Thymine
d. Guanine and Uracil
73. After adding guanine to tissue culture cells, what would you expect to happen to levels of
the other nucleotides in the culture?
a. dATP would decrease, dTTP would increase, dCTP would be unaffected
b. dATP and would increase, dTTP and dCTP would be unaffected
c. dATP would increase, dTTP and dCTP would decrease
d. dATP would be unaffected, dTTP and dCTP would decrease
e. dATP would be unaffected, dTTP and dCTP would increase
74. Which of the following base can be used to treat Orotic Aciduria?
a. Adenocine
b. Uridine
c. Guanosine
d. Thymidine
75. Over-prescription of allopurinol could feasibly result in what condition?
a. Gout
b. Various immune deficiencies
c. Symptoms akin to those caused by chemotherapy
d. Xanthinuria
e. Uric acidemia
76. Which of the following enzyme is inhibited by 5-fluorouracil (5-FU)?
a. Ribonucleotide reductase
b. CTP synthetase
c. Orotidylic acid decarboxylase
d. Thymidylate synthase
e. Carbamoyl phosphate synthetase
17
77. Which of the following is the catabolism product of Thymine?
a. Beta-Alanine
b. Beta-Aminoisobutyrate
c. Alpha-Alanine
d. Alpha-Aminoisobutyrate
78. 5-Flurouracil (5-FU) is an inhibitor of which enzyme?
a. Thymidylate synthase
b. Formyl Transferase
c. Ribonucleotide Reductase
d. CTP synthetase
e. Dihydroorotase
79. Which of the following THF is used in de novo purine synthesis?
a. N10formyl H4folate
b. N5N10formyl H4folate
c. N5formyl H4folate
d. N5N10methyl H4folate
80. In comparing pyrimidine and purine biosynthesis, which of the following is false?
a. Both utilize PRPP as the source of ribose
b. Both are made from abundant compounds such as amino acids
c. Both involve the formation of a ring off of a ribose group
d. Both create a purine or pyrimidine respectively that is further modified to achieve
the proper final product
e. All of the above are true
81. Which of the following is the commonly ingested form of B12?
a. CN(cyano) - B12
b. OH(hydroxyl) - B12
c. CH3(methyl) - B12
d. 5’ deoxyadenosyl - B12
82. Which of the following form of B12 is found in the liver?
a. Bound to Transcobalamin I
b. Bound to Transcobalamin II
c. Bound to intrinsic factor
d. Bound to a 3-ring-binder
18
83. Identify the proper compounds which are needed in forming a pyrimidine ring.
a. Glutamine, CO2, Glycine
b. Glutamate, CO2, Aspartate
c. Glutamate, CO2, Glycine
d. Glutamine, CO2, Aspartate
e. ATP, magic, and a shit ton of luck
84. Which of the following deficiency lead to buildup of homocysteine?
a. Deficiency in 5-formyl THF
b. Deficiency in 5-methyl THF
c. Deficiency in 10-formyl THF
d. Deficiency in 10-methyl THF
e. Deficiency in 5,10-methylene THF
85. A patient is supposed to be undergoing chemotherapy, but you are skeptical that the
patient is taking her drugs. After testing her urine, it was found to have β-aminobutyrate
present. Would this be expected if she was taking her medication, and what is β-aminobutyrate
a product of?
a. β-aminobutyrate is an antimetabolite used in chemotherapy treatment and would be
expected to be found if the patient is taking her medication
b. β-aminobutyrate is a product of cytosine degredation and should not be in a patient’s
urine if the patient is taking the chemo medication
c. β-aminobutyrate is a product of thymine degradation, and would be expected if the
patient is taking the chemo medication
d. β-aminobutyrate should be present in her urine, but that’s because it’s present in
everybody’s urine
e. β-aminobutyrate is a product of excessive DNA breakdown, but it is deposited in fat and
should not be found in urine
86. Identify the following base.
a.
b.
c.
d.
e.
Uracil
Thymine
Adenine
Cytosine
Guanine
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Glycogen Metabolism
87. How many residues are transferred using the branching enzyme?
a. 4
b. 5
c. 6
d. 7
e. 8
88. What is the name of the enzyme that converts glucose-1-phosphate to UDP-glucose?
a. Phosphoglucomutase
b. Glucose-1-phosphatase
c. UDP glucose pyrophosphorylase
d. Phosphorylase
e. Branching Enzyme
89. What kind of molecular reaction in responsible for ‘turning off’ glycogen synthase?
a. A phosphate group is added to the enzyme using a protein kinase
b. Insulin stimulates a protein phosphatase that cleaves off a phosphate group
c. It reacts with AMP and which inhibits the enzyme
d. The enzyme clumps together with other enzymatic subunits to form a less active
chain
e. Glycogen is used as an inhibitor of the enzyme
90. What two molecules are needed to initially start glycogen synthesis?
a. Glucose-1-phosphate & Glycogenin
b. Glucose-6-phosphate & Glucose
c. Glycogenin & UDP-Glucose
d. Glucose-1-phosphate & UDP-Glucose
e. Glucose & Phosphate
91. Which of the following diseases comes about from a defective branching enzyme?
a. Von Gierke’s disease
b. McArdles disease
c. Pompe disease
d. Tay-Sachs disease
e. Andersen disease
20
92. Neither the muscle nor the brain can synthesize glucose from lactate, because neither has
the enzyme:
a. Glucose-6-phosphatase
b. Glucose-3-phosphatase
c. Acetyl-CoA Carboxylase
d. Propionyl-CoA Carboxylase
e. Pyruvate Carboxylase
93. Consider the process of glycogen metabolism. Which glycosidic bond is hydrolyzed by the
debranching enzyme?
a. α (14)
b. α (16)
c. β (14)
d. β (16)
e. None of these
94. All of the following are true of glycogenolysis EXCEPT:
a. Glycogen is broken down from the non-reducing end by glycogen phosphorylase
b. Glucagon stimulates in both liver and muscle tissue
c. Glycogen phosphorylase uses vitamin B6 as a cofactor and cleaves at α 1:4 linkages
d. Glucosidase cleaves at α 1:4 linkages
e. Both B and D
f. All of the above
95. Choose the correct statement about glycogen synthesis:
a. The primer for de novo synthesis only includes glycogenin
b. UDPG is the main donor of glucosyl units
c. UDPG Pyrophosphorylase is the main regulatory enzyme
d. The branching enzyme transfers 7 glucose units from α 1:4 to form α 1:6 branch
e. Both B and D
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96. Which of the following is a correct series of steps in activating glycogenolysis in the liver?
(some steps may be skipped)
a. Epinephrine is released into the bloodAdenylate cyclase is activated ATP is
cleaved to become CAMP Protein kinase A phosphorylates phosphorylase
kinase Phosphorylase A is phosphorylated and becomes active
b. Glucagon is released into the bloodCAMP is activephosphorylase B becomes
activeProtein kinase A becomes inactive Phosphorylase A becomes
dephosphorylated and thus active
c. Glucagon is released into the blood Adenylate cyclase activates CAMPProtein
kinase A phosphorylates phosphorylase kinase phosphorylase kinase
phosphorylates phosphorylase  Phosphorylase A is now active and breaks down
glycogen
d. Epinephrine is released into the blood  Protein kinase A phosphorylates
phosphorylase kinase  CAMP is active  phosphorylase kinase dephosphorylates
phosphorylase Adenylate cyclase in inactivated
97. Choose the correct statement about the hormonal control of glycogen metabolism:
a. Phosphorylase A is inactivated by protein phosphatase 1(PPI)
b. When glycogen synthase is phosphorylated it becomes inactive
c. Phosphorylase B can be activated by phosphorylase kinase OR AMP
d. Both A and C
e. All of the above
98. A patient comes into your clinic complaining of fatigue during strenuous exercise. He says
he gets very painful muscle cramps whenever performing any sort of strenuous exercise, even
for short periods of time. You decide to run some tests and discover that he has moderately
increased glycogen in his muscles, but with normal structure, and thus conclude he has
McArdle’s disease. From your knowledge of glycogen storage disease, you know your patient
has a deficiency in what enzyme:
a. Glucose-6-phosphatase
b. Α 1:4 α 1:6 branching enzyme
c. Glycogen phosphorylase
d. Α 1:4 glucosidase
e. Phosphofructokinase
Cell Signaling
99. Choose the correct statement regarding hormones:
a. Steroid hormones are released into the blood by passive diffusion
b. Peptide hormones have a rapid onset and short duration
c. Catecholamines store fully active signals in secretory vesicles
d. Only A and C
e. All of the above
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100. Choose the correct statement:
a. Paracrine signaling includes a signal that acts on the cell which released the signal
b. Regulated exocytosis is found only in specialized cells and considered always “on”
c. The community effect is an example of paracrine signaling
d. Endocrine signals are more dilute and require high affinity receptors
e. All of the above
101. Which of the following are correct about steroid hormones and receptors:
a. Acetylcholine, nerve growth factor, and serotonin are examples of steroid hormones
b. The receptors are located on the plasma membrane and contain 7 membrane
spanning regions
c. The steroid hormone cortisol can act on lymphocytes and cause immune
suppression
d. The steroid hormone receptor activates a secondary messenger once the hormone
binds
e. None of the above
102. Which of the following concerning insulin signaling is correct:
a. One molecule of insulin is required to fully activate the receptor
b. In the growth pathway, Shp is phosphorylated, which activates Ras, which eventually
leads to activation of transcription factors controlling growth
c. In the glucose uptake pathway, PI3K is phosphorylated, initiating a cascade that
leads to increase number of glucose transporters being degraded
d. Both B and C
e. All of the above
103. All of the following are true of G-protein linked receptors EXCEPT:
a. They contain 7 membrane spanning regions
b. Ca+2, IP3, and cAMP are examples of secondary messengers
c. GTP is bound to the α subunit at rest (non-excited state)
d. Both A and B
e. All of the above
Gluconeogenesis
104. All of the following are true of gluconeogenesis EXCEPT:
a. 4 key enzymes are pyruvate carboxylase, PEP carboxykinase, fructose 1,6
bisphosphatase, and glucose-6-phosphatase
b. It occurs in muscle
c. It occurs during times of prolonged fasting or diabetes
d. ATP is required
e. None of the above
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105. Which of the following is true of biotin:
a. It is the coenzyme for pyruvate carboxylase and acetyl-CoA carboxylase
b. It is acquired through the diet by means of eggs and deficiency is very common
c. It serves to carry CO2 in reactions
d. Biotinidase covalently links biotin to a lysine residue on the enzyme
e. Only A and C
f. All of the above
106. All of the following are true of the reaction of pyruvate
PEP, EXCEPT:
a. It takes place in the mitochondria and the cytoplasm
b. It uses two enzymes, pyruvate carboxylase in the cytoplasm and PEP carboxykinase
in the mitochondria
c. It requires expenditure of 3 high energy bonds
d. Both B and C
e. All of the above
f. None of the above
107. Which of the following is not true regarding the regulation of gluconeogenesis and
glycolysis:
a. Glucagon stimulates glycolysis and inhibits gluconeogenesis
b. Acetyl-CoA stimulates pyruvate carboxylase
c. ATP inhibits pyruvate kinase and stimulates fructose 1,6 bisphosphatase
d. Citrate stimulates phosphofructokinase and inhibits fructose 1,6 bisphosphatase
e. Both A and D
108. Choose the correct number of ATP, GTP, and NADH required to make 1 glucose from
pyruvate:
a. 2 ATP, 2 GTP, 4 NADH
b. 4 ATP, 2 GTP, 4 NADH
c. 4 ATP, 2 GTP, 2 NADH
d. 2 ATP, 1 GTP, 2 NADH
e. None of the above
109. What is the nature of the biotin enzyme linkage?
a. It is an amide linkage to a glutamine residue
b. It is an amide linkage to a lysine residue
c. It is an amide linkage to a histidine residue
d. It is an ester linkage to a lysine residue
e. It is an ester linkage to a glutamine residue
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110. What enzyme do brain and muscle lack that they cannot synthesize glucose from lactate?
a. Glycerol kinase
b. Glucose-6-phosphatase
c. Pyruvate kinase
d. Lactate dehydrogenase
e. Hexokinase
111. In what organ are lactate and alanine converted to glucose?
a. Heart
b. Brain
c. Liver
d. Muscle
e. Adipose
112. How many molecules of ATP and GTP, respectively, are required to synthesize glucose in
the liver?
a. 4, 2
b. 2, 4
c. 6, 4
d. 6, 2
e. 2, 6
113. Which of the following an inhibitor of Fructose-1,6-bisphosphatase?
a. ATP
b. Citrate
c. Fructose
d. AMP
e. ADP
Folates & B-12
114. S-adenosylmethionine is an important cosubstrate in many reactions. What is its main
function in these reactions?
a. It donates an acetyl group
b. It donates an acyl group
c. It donates a methyl group
d. It donates a single hydrogen
e. It donates a ethyl group
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115. In the folate trap hypothesis, it is thought that an effective deficiency of folate can occur
even if a person’s intake of folate is adequate. What is the key reaction which is involved with
the folate trap, and what is the cause of the trap?
a. Folate is trapped in the step involving the loss of a methyl group N5N10methyl
H4folate to 5-methyl THF, and this is due to a deficiency of B12 vitamin
b. Folate is trapped in the step involving the loss of a methyl group from 5-methyl THF
to THF, and this is due to a deficiency of B12 vitamin
c. Folate is trapped in the step involving the loss of a methyl group from N5N10methyl
H4folate to 5-methyl THF, and this is due to a lack of methionine acting as an Nacceptor
d. Folate is trapped in the step involving the loss of a methyl group from N5N10methyl
H4folate to 5-methyl THF, and this is due to homocysteinemia acting as an inhibitor
of the step
e. Folate is trapped in the step involving the loss of a methyl group from 5-methyl THF
to THF, and this is due to a person having megaloblastic anemia inhibiting the
activation of THF
116. Which enzyme(s) require vitamin B12 for proper function in human beings?
a. Methionine synthase
b. Formyl transferase
c. Thymidylate synthase
d. Methylmalonyl CoA mutase
e. A + B
f. B + C
g. A + D
h. All of the above
117. In comparing B12 and folate, which of the following is NOT true?
a. A deficiency of either during pregnancy could result in neural tube defects
b. Both are stored in the liver
c. Both require some amount of digestion prior to uptake into the blood
d. Both are synthesized solely by microorganisms
e. A deficiency of either can result in homocysteinemia
2013 Block 1 Unit 2 Practice Questions
Written/Compiled by John Luckoski
Many thanks are due to Shane Sheahan, Kevin Carbone, and Dan Feldman for writing the majority of these questions. Also, I
highly suggest looking at the formative questions written by the professors that are on blackboard.
This is all student-made, and thus prone to error. If you find any mistakes make it known! I wish you all way more than luck.
AND DON'T FORGET ABOUT THE SELF STUDY!!!
1. D
2. C
3. C
4. A
5. A
6. B
7. D
8. B
9. C
10. B
11. C
12. A
13. C
14. D
15. E
16. B
17. B
18. B
19. A
20. B
21. C
22. E
23. B
24. C
25. D
26. D
27. A
28. A
29. D
30. C
31. C
32. D
33. E
34. C
35. E
36. B
37. C
38. F
39. A
40. B
41. E
42. C
43. B
44. E
45. C
46. A
47. B
48. A
49. E
50. D
51. C
52. D
53. D
54. A
55. E
56. C
57. D
58. B
59. A
60. D
61. C
62. G
63. A
64. B
65. C
66. A
67. D
68. C
69. D
70. E
71. A
72. B
73. C
74. B
75. D
76. D
77. B
78. A
79. A
80. C
81. B
82. A
83. D
84. B
85. C
86. D
87. D
88. C
89. A
90. C
91. E
92. A
93. B
94. E
95. E
96. A
97. E
98. C
99. E
100. D
101. C
102. B
103. C
104. B
105. E
106. C
107. E
108. C
109. B
110. B
111. C
112. A
113. D
114. C
115. B
116. G
117. D
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