CHAPTER ONE
BIOCHEMISTRY: AN INTRODUCTION
1) The ultimate source of energy for life on earth is __________.
A) The sun
B) Geothermal heat
C) Carbohydrates
D) Fats
E) Other organisms
Ans A
2) Which of the following is not a common component of biomolecules?
A) Carbon
B) Hydrogen
C) Oxygen
D) Nitrogen
E) Chlorine
Ans E
3) Which of the following is the basic structural unit of living organisms?
A) Nucleus
B) Cell membrane
C) Tissue
D) Cell
E) Cytoskeleton
Ans D
4) Which of the following is not an organelle?
A) Mitochondria
B) Chloroplast
C) Nucleus
D) Plasma membrane
E) Golgi complex
Ans D
5) Which of the following is not a role played by carbohydrates in living cells?
A) Energy source
B) Structural support
C) Intercellular communication
D) Both A and B are correct
E) All are roles played by carbohydrates in living cells
Ans E
6) Metabolism is best defined as the _________.
A) Reactions of living cells
B) Reactions that synthesize large molecules in living cells
C) Reactions that degrade molecules in living cells
D) Conversion of food molecules to energy
E) Reactions that synthesize and degrade molecules in living
cells Ans E
7) The average life span of a species is about ________years
A) One million
B) Ten million
C) Five hundred thousand
D) Five million
E) One hundred thousand
Ans A
8) Which of the following is not a waste product of living organisms
A) Carbon dioxide
B) Water
C) Urea
D) Ammonia
E) Glycine
Ans E
9) Biochemistry is defined as
A) The study of life processes
B) The study of the molecular basis of life
C) The study of living organisms
D) The study of organic compounds in living organisms
E) The study of living compounds
Ans B
10) One of the principal methods that organisms use to obtain energy from chemical bonds is by
___________.
A) Substitution reactions
B) Dehydration reactions
C) Oxidation/reduction reactions
D) Hydration reactions
E) Addition reactions
Ans C
11) The following is an example of which reaction class?
CH3Br + HSCH2CH(NH2)COOH → CH3SCH2CH(NH2)COOH + Br- + H+
A) Substitution
B) Elimination
C) Addition
D) Isomerization
E) Oxidation/Reduction
Ans A
12 The following is an example of which reaction class
HOOCCH=CHCOOH + H2O → HOOCCH2CH(OH)COOH
A) Substitution
B) Elimination
C) Addition
D) Isomerization
E) Oxidation/Reduction
Ans C
13) The following is an example of which reaction class?
CH3CH2OH → CH3CHO + H2O
A) Substitution
B) Elimination
C) Addition
D) Isomerization
E) Oxidation/Reduction
Ans E
14) Which of the following is not a component of nucleic acid?
A) Nucleotides
B) Glucose
C) Phosphate group
D) Purines
E) Pyrimidines
Ans B
15) The largest molecules in living organisms are _________.
A) proteins
B) lipids
C) nucleic acids
D) carbohydrates
E) steroids
Ans C
16) All of the following classes of compounds are lipids except _______.
A) fats
B) sterols
C) fatty acids
D) phosphoglycerides
E) nucleotides
Ans E
17) Which of the following classes of biomolecules are the most abundant in nature?
A) Lipids
B) Amino acids
C) Carbohydrates
D) Proteins
E) Nucleotides
Ans C
18) Consider the following molecule. Which arrow is pointing to a peptide bond?
A) A
B) B
C) C
D) D
E) E
Ans C
19) The following molecule is an example of which single class of compounds?
CH3CH2CH(NH2)COOH
A) Amine
B) Acid
C) Ester
D) Amino acid
E) Alcohol
Ans D
20) The following molecule is an example of which class of
compounds? CH3CH2CH2COOCH2CH3
A) Hydrocarbon
B) Acid
C) Ester
D) Ether
E) Aldehyde
Ans C
21) The following molecule is an example of which class of
compounds? CH3CH2CH2COOH
A) Hydrocarbon
B) Acid
C) Alcohol
D) Aldehyde
E) Ketone
Ans B
22) The chemical properties of organic molecules are determined by specific arrangements of
atoms called _____________.
A) Structure
B) Bonds
C) Functional groups
D) Radicals
E) Molecules
Ans C
23) Which of the following classes of compounds make up most of the mass of an organism?
A) Amino acids
B) Proteins
C) Lipids
D) Carbohydrates
E) Water
Ans E
24) Which of the following is not a basic element of life
A) Phosporus
B) Hydrogen
C) Nitrogen
D) Oxygen
E) All of the above are basic elements of life
Ans E
25) Most biomolecules can be considered to be derivatives of
A) Amino acids
B) Carbohydrates
C) Fats
D) Hydrocarbons
E) Alcohols
Ans D
26) Which of the following amino acids contain a hydrophobic side chain
A) Leucine
B) Arginine
C) Glutamine
D) Glutamic acid
E) Aspartic acid
Ans A
27) Which of the following small molecules do not for biopolymers
A) Amino acids
B) Sugars
C) Fatty acids
D) Nucleotides
E) C and D
Ans C
28) Choose the amino acid that can function as a neurotransmitter
A) Glutamic acid
B) Alanine
C) Tyrosine
D) Lysine
E) Cysteine
Ans A
29) A constant source of _______ is required for maintenance of a cell’s ordered state.
A) Heat
B) Oxygen
C) Energy
D) Stimulus
E) Water
Ans C
30) Which of the following is not true of life?
A) Life is cellular
B) Life is information based
C) Life is complex and dynamic
D) All living things produce energy using mitochondria
E) Life adapts and evolves
Ans D
31) The most abundant biomolecules found in nature are
A) Amino acids
B) Fatty acids
C) Carbohydrates
D) Proteins
E) Fats
Ans C
32) Which of the following is not a component of DNA
A) Uracil
B) Adenine
C) Cytosine
D) Guanidine
E) Thymine
Ans A
33) The sum total of all reactions of a organism is called
A) Life
B) Metabolism
C) Biosynthesis
D) Anabolism
E) Energetics
Ans B
34) Which of the following is not characteristic of an autopoietic system?
A) Autonomous
B) Self-organizing
C) Self-maintaining
D) Intelligent
E) B and D
Ans D
35) The assumption that a complete understanding of a living organism can be obtained solely
by investigating all of its components is called _________.
A) Systems biology
B) Reductionism
C) Emergence
D) Robustness
E) Feedback control
Ans B
36) Which of the following is not a core principle of systems biology?
A) Emergence
B) Robustness
C) Redundancy
D) Modularity
E) Limit of resolution
Ans E
37) The field of study associated with the investigation of gene expression patterns is called:
A) Proteomics
B) Bioinformatics
C) Genomics
D) Functional genomics
E) Synomics
Ans D
38) Which of the following is not an example of a macromolecule?
A) Nucleic acid
B) Protein
C) Polysaccharide
D) Enzyme
E) Amino acid
A) E
39) Which of the following is not considered a class of small biomolecule?
A) Amino acid
B) Sugar
C) Nucleic Acid
D) Fatty acid
E) Nucleotide
Ans C
40) The functional group present in the following molecule is called:
A) Amine
B) Ketone
C) Amide
D) Ester
E) Acid
Ans C
41) The majority of Earth’s species belong to which of the following classifications
A) Eukaryotes
B) Prokaryotes
C) Viruses
D) Mammals
E) Archea
Ans B
42) The conversion of earths atmosphere from anerobic to aerobic was due to the development of
_________________ by cyanobacteria
A) Photosynthesis
B) Metabolism
C) Chemosynthesis
D) Oxidation of iron
E) Fixation of nitrogen as cyanide
Ans A
43) The largest mass extinction also known as the great dying was called the
A) Cenezoic extinction
B) Permian extinction
C) Mesozoic event
D) Great ice age
E) The great plague
Ans B
44) The most prominent function of RNA is
A) Energy source
B) Nutrient source
C) Protein synthesis
D) Structural elements
E) B and C
Ans C
45) An organisms entire set of DNA is called
A) Genome
B) Genetic sequence
C) Polynucleotide sequence
D) Gene
E) Inheritance
Ans A
46) The major function of carbohydrates is
A) Catalysts and structural elements
B) Energy sources and structural elements
C) Genetic information
D) Protein synthesis
E) Insulation
Ans B
CHAPTER TWO
LIVING CELLS
1) During exocytosis membrane-bound vesicles migrate from the Golgi apparatus to the
__________.
A) Lysosome
B) Smooth endoplasmic reticulum
C) Cell wall
D) Plasma membrane
E) More than one answer is correct
Ans D
2) Notable features of eukaryotes include all of the following except ________.
A) Rapid cell division
B) Larger size
C) A complex internal structure
D) An endomembrane system
E) Organelles
Ans A
3) Gram-negative bacteria lack _________.
A) Cell walls
B) Peptidoglycans in the cell wall
C) An outer coat of lipid bound proteins
D) DNA
E) Carbohydrate containing polymers in the cell wall
Ans E
4) The plasma membrane _________.
A) Provides support
B) Is present only in eukaryotes
C) Controls the flow of substances in and out of the cell
D) Is present only in prokaryotes
E) Both A and C are correct
Ans E
5) Structural features that make phospholipids suited for their biological role are:
A) A hydrophilic head group
B) Branched carbon chains
C) A hydrophobic group
D) A and C are correct
E) None of the above are true
Ans D
6) The grainy appearance of prokaryotic cytoplasm is due in part to ________.
A) A large number of ribosomes
B) Plasmids
C) Nucleolus
D) DNA
E) RNA
Ans A
7) Which of the following types of molecules is not hydrophilic
A) Sodium chloride
B) Glucose
C) Amino acids
D) Fats
E) A and B
Ans D
8) The basic structure of biological membranes is provided by what class of compounds?
A) Proteins
B) Lipids
C) Carbohydrates
D) Steroids
E) Peptidoglycans
Ans B
9) Which of the following is not true of the nucleus?
A) It is found in both eukaryotes and prokaryotes
B) It contains the cell’s “genetic blueprint”
C) It exerts a profound influence over all cellular metabolic functions
D) It contains chromatin fibers
E) It is bounded by membrane
Ans A
10) Which of the following statements is not true of the endoplasmic reticulum?
A) It often constitutes more than half of the cell’s total membrane
B) It exists in two forms: rough and smooth
C) Rough ER is responsible for protein synthesis
D) Smooth ER is responsible for lipid synthesis
E) Rough ER ribosomes are responsible for
biotransformation. Ans E
11) Which of the following is not true of eukaryotic ribosomes?
A) They are macromolecular machines
B) They function in the biosynthesis of proteins
C) They contain ribosomal RNA
D) They consist of two unequally sized subunits
E) They are attached to the smooth ER
Ans E
12) Which of the following statements is not true of the Golgi apparatus?
A) The analogous plant structure is referred to as a
dictyosome B) It has two faces
C) The cisterna or forming face usually projects toward the ER
D) It is involved in the packaging and secretion of cell
products E) It is usually located near the plasma membrane
Ans E
13) Which of the following statements is not true of the lysosome?
A) It functions in intercellular digestion
B) Both ER and Golgi apparatus are involved in its
formation C) It is capable of degrading most biomolecules
D) It is involved in the packaging and secretion of cell products E) It is
involved in pathological conditions such as gout and rheumatoid arthritis
Ans D
14) Acid hydrolases are found in ___________.
A) Ribosomes
B) Lysosomes
C) Golgi Apparatus
D) Dictyosomes
E) Smooth ER
Ans B
15) The main role of peroxisomes is _____________.
A) Anaerobic respiration
B) Aerobic respiration
C) Lipid oxidation
D) Generation and destruction of peroxides
E) Carbohydrate oxidation
Ans D
16) Biological machines are derived from which class of compounds
A) Fats
B) Proteins
C) Carbohydrates
D) Ribosomes
E) B and C
Ans B
17) Which of the following organelles is involved in aerobic metabolism?
A) Mitochondria
B) Peroxisomes
C) Glyoxysomes
D) Ribosomes
E) Lysosomes
Ans A
18) Respiratory assemblies are responsible for the synthesis of ___________.
A) ATP
B) NADH
C) GTP
D) Hydrogen peroxide
E) ADP
Ans A
19) The two membranes of the mitochondria create two separate compartments called the
intermembrane space and the __________.
A) Cristae
B) Matrix
C) Lumen
D) Cisternae
E) Vesicle
Ans B
20) Which of the following statements is not true of the mitochondrial matrix?
A) It contains enzymes responsible for nucleotide metabolism
B) It contains circular DNA molecules
C) It contains all of the necessary compounds for protein synthesis
D) It has a gel-like consistency
E) It has a high concentration of enzymes and ions
Ans A
21) The excluded volume of a cell varies between _____ and ______%.
A) 5-10
B) 10-20
C) 20-40
D) 40-50
E) 0-5
Ans C
22) Plastids are plant structures similar to what organelle found in animals?
A) Ribosomes
B) Leucoplasts
C) Golgi apparatus
D) Peroixsomes
E) None of the above is correct
Ans E
23) The stroma of plastids is analogous to what structure of mitochondria?
A) Grana
B) Matrix
C) Inner membrane
D) Outer membrane
E) Cisternal space
Ans B
24) Which of the following help make up the cytoskeleton?
A) Microtubules
B) Microfilaments
C) Intermediate fibers
D) B and C are correct
E) All are correct
Ans E
25) Mitochondria and _________ consume molecular oxygen.
A) Plastids
B) Ribosomes
C) Peroxisomes
D) Lysosome
E) Golgi apparatus
Ans C
26) Which of the following is present only in prokaryotic cells?
A) Nucleus
B) Endoplasmic reticulum
C) Plasma membrane
D) Nucleolus
E) None of the above is correct
Ans E
27) Biotransformation is defined as:
A) The preparation of water-insoluble substances for excretion
B) Oxidation of organic molecules
C) Transformation of food molecules to ATP
D) Reactions occuring within a living system
E) Conversion of harmless compounds to toxins
Ans A
28) In place of a nucleus a prokaryotic cell has a __________.
A) Mesosome
B) Nucleoid
C) Centrosome
D) Nucleosome
E) Reticulosome
Ans B
29) Which of the following eukaryotic organelles is a key regulator of apoptosis?
A) Mitochondria
B) Flagella
C) Chloroplasts
D) Cilia
E) Ribosomes
Ans A
30) Which of the following is not a role of transmembrane proteins?
A) Transport of ions
B) Structural support
C) Transport of nutrients
D) Receptors
E) Enzymes
Ans B
31) Which of the following is not a membrane protein?
A) Channel protein
B) Carrier protein
C) Receptors
D) Integral proteins
E) Motor proteins
Ans E
32) Examples of eukaryotic signal molecules are:
A) Neurotransmitters
B) Hormones
C) Cytokines
D) Both A and B are correct
E) All of the above are correct
Ans E
33) Which of the following is not a phase of the information processing mechanism?
A) Reception
B) Transduction
C) Response
D) Transformation
E) Both A and C are correct
Ans D
34) Which of the following is not a component of the endomembrane system?
A) Plasma membrane
B) Endoplasmic reticulum
C) Golgi apparatus
D) Lysosomes
E) Ribosomes
Ans E
35) The carbohydrate coat of a cell is called the:
A) Extracellular matrix
B) Glycocalyx
C) Cell cortex
D) Fibroblast
E) Both A and C are correct
Ans B
36) The perinuclear space is:
A) The space between the nucleus and the cytoplasm
B) The space between the membranes of the nuclear
envelope C) The space between the nucleus and the nucleous
D) The space between DNA and histones
E) Both A and B are correct
Ans B
37) Which of the following organelles are involved in autophagy?
A) Mitochondria
B) Lysosomes
C) Chloroplasts
D) Golgi apparatus
E) Both B and C are correct
Ans B
38) Which of the following molecules is not an example of a type of eukaryotic signal
molecule type?
A) Neurotransmitters
B) Hormones
C) Cytokinins
D) Endotoxins
E) A and B
Ans D
39 Of the 100 approximately trillion free living cells in the human body how many are actually
human cells?
A) All of them
B) 50 Trillion
C) 90 Trillion
D) 10 Trillion
E) 80 Trillion
Ans D
40) Analysis of the RNA of prokaryotes reveals that there are ______ distinct types of
prokaryotes.
A) One
B) Two
C) Three
D) Four
E) Five
Ans B
41) Which of the following are microbiota
A) Bacteria
B) Fungi
C) Archea
D) A and B
E) A, B and C
Ans E
42) Which of the following are techniques used by the body to protect itself
against indigenous micobiota
A) Impenetrable epithelial tissue
B) Immune system cells
C) Antimicrobial proteins
D) Beta defensins
E) All of the above
Ans E
43) Which of the following is a superorganism
A) Streptococcus
B) Lactobacillus
C) Homo Sapiens
D) Corynebacterium
E) Klebsiella
Ans C
44) The endocytotic cycle is
A) A means of remodeling plasma membrane
B) A form a signal transduction
C) Cycling of sodium and potassium ions through the cell membrane D)
Continuous recycling of membrane through endocytosis and exocytosis E)
A and D
Ans A
CHAPTER THREE
WATER THE MATRIX OF LIFE
1) The most important factor in the evolution of life on earth is _______.
A) The sun
B) Oxygen
C) Water
D) Dry land
E) A reducing atmosphere
Ans C
2) A hydrogen bond is best defined as:
A) A strong chemical bond between hydrogen and another element
B) A weak chemical bond between hydrogen and another element
C) A relatively strong electrostatic bond between hydrogen and oxygen or nitrogen
D) A weak electrostatic bond between hydrogen and oxygen or nitrogen E) A bond
between two hydrogens
Ans C
3) Which of the following compounds is capable of hydrogen bonding with like molecules?
A) CH3CH2CH2CH2CH3
B) CH3CH2OCH2CH3
C) CH3NH2
D) HOCH2CH2OH
E) Both C and D are correct
Ans E
4) Which of the following is not a type of van der Waals force?
A) Dipole-dipole interactions
B) Dipole-induced dipole interactions
C) Induced dipole – induced dipole interactions
D) Chemical bonds
E) Hydrogen bonds
Ans D
5) Which of the following is not an example of noncovalent interactions between molecules?
A) Salt bridges
B) Hydrogen bonds
C) Hydrophobic interactions
D) Ionic bonds
E) Chemical bonds
Ans E
6) Which of the following factors is responsible for the fact that water is a liquid at room
temperature?
A) Covalent O-H bonds
B) Ionic bonds
C) Hydrogen bonds
D) Hydrophobic bonding between water molecules
E) The molecular weight of water
Ans C
7) Which of the following properties of water promotes the relatively constant climate of earth?
A) High heat of fusion
B) High surface tension
C) High heat of vaporization
D) High heat capacity
E) A, C, and D are all important
Ans E
8) Which of the following compounds is amphipathic?
A) H2O
B) CH3CH2CH2CH2CH3
C) HOOCCOOH
D) CH3CH2CH2CH2COOH
E) Both A and D are correct
Ans D
9) Which of the following is a hydronium ion?
A) H3O+
B) OH
C) HOOH
D) CH3OH2+
E) H4O++
Ans A
10)Which of the following is the conjugate acid of the bicarbonate
ion? A)
B)
C)
D)
E)
Ans B
11) Which of the following statements is true of weak acids dissolved in water?
A) They are completely ionized in water
B) They are totally unionized in water
C) They are partially ionized in water
D) The dissociation constant is a function of pH
E) The dissociation constant is a function of solute concentration
Ans C
12) What is the pH of a solution where the concentration of hydrogen ions is 2 x 10-5
molar? A) 5
B) 2.5
C) 2
D) 4.7
E) 5.3
Ans D
13) Which of the following would not form a suitable buffer?
A) Acetic acid/ acetate
B) Carbonic acid/ bicarbonate
C) Bicarbonate/ carbonate
D) Hydrochloric acid/ chloride
E) Phosphoric acid/ dihydrogen phosphate
Ans D
14) Buffering capacity is directly proportional to which of the following factors?
A) Molecular weight of the buffer
B) Concentration of the conjugate acid of the buffer
C) Concentration of the conjugate base of the buffer
D) Concentration of both components of the buffer
E) The acid or base to be buffered against
Ans D
31) The sodium acetate/acetic acid buffer is 0.1 molar in sodium acetate and 0.5 molar
in acetic acid. What is the concentration of the buffer?
A) 0.1 molar
B) 0.5 molar
C) 0.6 molar
D) 0.4 molar
E) Either A or B depending on whether acid or base is being added to the buffer.
Ans C
16) The pH of a solution that is 0.25 molar in acetic acid and 0.1 molar in sodium acetate is
4.36. What is the pKa of acetic acid?
A) 4.36
B) 4.76
C) 7.76
D) 3.76
E) 5.76
Ans B
17) The most important buffer in blood is __________.
A) Carbonate/bicarbonate buffer
B) Protein buffer
C) Phosphate buffer
D) Lactate buffer
E) Tartrate buffer
Ans A
18) When an individual breathes very rapidly, large amounts of carbon dioxide are exhaled.
What effect does this have on blood pH?
A) Acidosis
B) Alkalosis
C)No change
D) First acidosis then rebounding alkalosis
E) First alkalosis then rebounding acidosos
Ans B
19) Salt bridges in proteins are an example of _________.
A) Hydrogen bonds
B) Ionic interactions
C) Hydrophobic interactions
D) van der Waals forces
E) London dispersion forces
Ans B
20) What is the osmorlarity of a solution that is 0.25 molar in trisodium phosphate?
A) 0.25 osmolar
B) 0.5 osmolar
C) 0.75 osmolar
D) 1.0 osmolar
E) None of the above are correct
Ans D
21) Red blood cells are isotonic to a solution that is 0.9% sodium chloride. These same cells are
_______________ to a solution that is 0.9% sodium sulfate.
A) Isotonic
B) Hypertonic
C) Hypotonic
D) Tonic
E) Nontonic
Ans C
22) Which of the following molecules would have a dipole moment?
A) CCl4
B) CH3CH3
C) H2
D) CHCl3
E) I2
Ans D
23) Which of the following molecules would form a micelle?
A) NaCl
B) CH3COOH
C) CH3CH2CH2CH2CH2CH3
D) H3PO4
E) CH3(CH2)10COO- Na +
Ans E
24) Which of the following molecules are weak acids?
A) HCl
B) CO3-2
C) HNO3
D) HCO3E) Both B and D
Ans D
25) Which of the following ions would have the largest hydration sphere?
A) Li+
B) Na+
C) K+
D) Cs+
E) All would have the same size hydration sphere
Ans A
26) Hydration is best defined as
A) Covalent interaction between water and a solute
B) Noncovalent interaction between water and a solute
C) Salt formation in water
D) Ionization of a base to produce hydroxide ions
E) Both C and D are correct
Ans B
27) The noncovalent interaction between an amide and an alcohol would be which of the
following?
A) Salt bridges
B) Hydrophobic
C) Hydrogen bonding
D) Both A and C are correct
E) All of the above are true
Ans C
28) Crenation would result when cells are placed in a ___________ solution.
A) Hypertonic
B) Hypotonic
C) Isotonic
D) Nontonic
E) Nonaqueous solvent
Ans A
29) Which of the following is not an important noncovalent interaction of living organisms
A) Ionic interactions
B) Van der Waals interactions
C) Hydrogen bonds
D) Carbon hydrogen bonds
E) All are important
Ans D*
30) Which of the following molecules would have unusually high heat capacities?
A) Ammonia
B) Methane
C) Methyl alcohol
D) Benzene
E) Both A and C are correct
Ans E
31) The hybridization of the water molecule is:
A) Sp3
B) Sp2
C) Sp
D) Unhybridized
E) Planar
Ans A
32) The strongest type of non covalent force is
A) Dipole-Dipole
B) Dipole-Induced Dipole
C) Induced Dipole – Induced Dipole
D) London dispersion forces
E) Hydrogen bonds
Ans E
33) Which of the following ions would have the strongest tendency to form an ion pair with
carboxylate groups the surface of a protein?
A) Lithium
B) Sodium
C) Potassium
D) All have the same tendency
E) These ions do not associate with proteins
Ans C
34) Which of the following species would form a buffer with HPO4-2?
A) H3PO4
B) H2PO4-1
C) CO3-2
D) All would form buffers with HPO4-2
E) Both A and B
Ans B
35) Water can form how many hydrogen bonds
A) One
B) Two
C) Three
D) Four
E) Five
Ans D
36) Which of the following solutions will be isotonic with 3M sucrose?
A) 3M NaCl
B) 1 M Sodium sulfate
C) 1.5 M Proline
D) 2 M Sodium chloride
E) 1 M Magnesium sulfate
Ans B
37) Which of the following molecules is hydrophobic?
A) Sodium chloride
B) Ethyl alcohol
C) Hexane
D) Sucrose
E) Ammonia
Ans C
38) In biological systems buffers usually contain an excess of __________.
A) Weak base
B) Weak acid
C) The two components of the buffer are present in equal amounts
D) It would depend on the system
E) None are correct
Ans A
39) The tendency of nonpolar molecules to aggregate in a water medium is called ________.
A) Crenation
B) Hydrophobic effect
C) Hydrophillic effect
D) Micellular effect
E) Amphiatic
Ans B
40) The high heat of fusion of water is due to its _______________.
A) Hydrogen bonding
B) High surface tension
C) High heat of vaporization
D) High heat capacity
E) A, C, and D are all important
Ans A
41) Which of the following is not a role of water in the body
A) Nutrient absorption
B) Nutrient transport
C) Waste product excretion
D) Temperature regulation
E) All are roles of water
Ans E
42) Which of the following species can form a buffer system
A) Hydrochloric acid / Acetic acid
B) Acetic acid / Sodium chloride
C) Acetic acid / Ammonium chloride
D) Acetic acid/ Sodium acetate
E) Phosphoric acid / Sodium phosphate
Ans D
43) Which of the following are unusual properties of water that suit it to be the
matrix of life
A) Tetrahedral hybridization
B) Presence of oxygen
C) Thermal properties
D) Solvent characteristics
E) C and D
Ans E
44) What percentage of the worlds water is drinkable
A) 100%
B) 60%
C) 3%
D) 1%
E) 97%
Ans C
45) The immediate effect of deforestation is
A) Drought
B) Erosion
C) Formation of grasslands
D) Formation of deserts
E) Increase in the water table
Ans B
46) Which of the following is not an effect of hydrogen bonding on the
physical properties of water
A) Increased boiling point
B) Increased heat of fusion
C) Increased melting point
D) Increased heat of vaporization
E) All are effects of hydrogen bonding
Ans E
CHAPTER FOUR
ENERGY
1) The course of chemical reactions is determined by three factors. These are enthalpy, entropy
and
A) Heat of reaction
B) Free energy
C) States of matter
D) Bond energy
E) Both A and B are correct
Ans B
2) Which of the following statements is true of an open system
A) There is an exchange of energy only with the surroundings
B) There is an exchange of matter only with the surroundings
C) There is an exchange of both matter and energy with the surroundings D) In an
open system either matter or energy, but not both may be exchanged with the
surroundings
E) Energy flows only into the system: matter flows out of the
system. Ans C
3) Which of the following statements is true of a closed system?
A) There is an exchange of energy only with the surroundings
B) There is an exchange of matter only with the surroundings
C) There is an exchange of both matter and energy with the surroundings D) In an
closed system either matter or energy, but not both may be exchanged with the
surroundings
E) Energy flows only into the system: matter flows out of the
system. Ans A
4) Which of the following thermodynamic properties is a state function?
A) Work
B) Heat
C) Enthalpy
D) Entropy
E) Both C and D are correct
Ans E
5) The first law of thermodynamics is described by which of the following equations?
A) ∍E = Q+W
B) ∍Q = E-W
C) ∍W = Q-W
D) Both B and C are correct
E) All of the above are correct.
Ans A
6) Which of the following statements is not true of a spontaneous process?
A) The enthalpy value is negative
B) The entropy value is negative
C) The free energy value is positive
D) The work value is negative
E) The enthalpy value is positive
Ans B
7) Which of the following is not a standard condition for standard free energy?
A) 25 0C
B) 1 Atm pressure
C) Concentration of reactants = 1 molar
D) Concentration of products = 1 molar
E) pH = 7
Ans E
8) The ionization constant of acetic acid is 1x10-5. What is ∍Go for the reaction?
A) –6500 cal/mol
B) 3250 cal/mol
C) 6500 cal/mol
D) 6000 cal/mol
E) 1624 cal/mol
Ans C
9) Under standard conditions is the ionization of a carboxylic acid spontaneous or not? A typical
carboxylic acid has a pKa of 4.
A) It is spontaneous
B) It is not spontaneous
C) Not enough information is provided
Ans B
10) In order for two reactions to be coupled what conditions must be met?
A) They must both be spontaneous
B) One of the reactions must be spontaneous
C) A product of one of the reactions must be a reactant in the second
reaction D) They both must have ATP as a reactant
E) Both B and C must be true.
Ans E
11) When water and hydrophobic molecules are mixed all of the following are true except:
A) The hydrophobic molecules aggregate
B) The free energy of dissolving molecules is unfavorable
C) -T∍S becomes negative
D) Water’s hydrogen-bonded interactions are disrupted
E) All of the above are true.
Ans E
12) The oxidation of food molecules to form CO2 and H2O is a(n) _______ process.
A) Exergonic
B) Endergonic
C) Isothermic
D) Lithotropic
E) Spontaneous
Ans A
13) The most important direct source of energy in the body is:
A) ATP
B) ADP
C) GTP
D) Glucose
E) Fatty acids
Ans A
14) The law of the conservation of energy states that
A) The total energy of the universe is constant
B) Entropy of a system increases
C) There are three laws of thermodynamics
D) The work that can be performed by a system is a constant
E) The energy of a system’s surroundings is constant
Ans A
15) Which of the following is a low quality energy source
A) Electromagnetic radiation
B) Heat
C) Electrical Energy
D) Chemical Energy
E) B and C
Ans B*
16) Which of the following statements regarding free energy changes is true?
A) At equilibrium ∍G0 = O
B) For the reaction to be spontaneous ∍Go must be positive
C) Free energy is a state function
D) Both A and C are true
E) All of the above are true
Ans D
17) Which of the following compounds would liberate the most free energy on hydrolysis?
A) ATP
B) Phosphoenolpyruvate
C) PPi
D) ADP
E) GTP
Ans B
18) Which of the following thermodynamic properties is the most useful criterion of
spontaneity?
A) Entropy
B) Free energy
C) Standard free energy
D) Enthalpy
E) Change in temperature
Ans B
19) For a reaction to be spontaneous which of the following statements must be true?
A) ∍Suniv= O
B) ∍Suniv = positive
C) ∍Siniv = negative
D) A or B
E) Entropy has no effect on the spontaneity of a process
Ans B
20) Which of the following processes are driven by the hydrolysis of ATP?
A) Biosynthesis of biomolecules
B) Active transport of substances across membranes
C) Mechanical work such as muscle contraction
D) Both A and B are correct
E) All of the above are correct
Ans E
21) The study of reaction rates is called ___________.
A) Reactions
B) Thermodynamics
C) Kinetics
D) Mechanics
E) Entropics
Ans C
22) Which of the following is described by the first law of thermodynamics
A) Enthalpy
B) Entropy
C) Free energy
D) A and B
E) A, B and
Ans A
23) Which of the following is described by the second law of thermodynamics
A) Enthalpy
B) Entropy
C) Free energy
D) A and B
E) A, B and C
Ans B
24) What type of bond is being cleaved during the conversion of ATP to ADP?
A) Ester
B) Ether
C) Hydrogen
D) Anhydride
E) Amide
Ans D
25) The tendency of ATP to undergo hydrolysis is called __________.
A) Free energy of hydrolysis
B) Cleavage rate
C) Phosphoryl group transfer potential
D) High energy bond potential
E) None of the above is correct
Ans C
26) The products of the hydrolysis of ATP are more stable than ATP itself. This circumstance is
due to __________.
A) pH effects
B) Relief of charge-charge repulsions
C) Resonance stabilization of the products
D) Relief of steric strain
E) Both B and C are correct
Ans E
27) A living organism is what type of thermodynamic system?
A) Closed
B) Open
C) A system at equilibrium
D) A system with negative entropy
E) Both C and D are correct
Ans B
28) Which of the following thermodynamic properties is pathway
dependent? A) Free energy
B) Entropy
C) Enthalpy
D) Work
E) Both B and C are correct
Ans D
29) A Kelvin is _________.
A) A unit of temperature measurement
B) A unit of entropy measurement
C) A measurement of the density of a system
D) An index of the spontaneity of a reaction
E) A unit of heat
Ans A
30) The rate of a reaction can be determined from which of the following?
A) Free energy
B) Enthalpy
C) Entropy
D) All of the above are correct
E) None of the above are correct.
Ans E
31) To maintain a system far from equilibrium a constant input of _______ is required.
A) Entropy
B) Energy
C) Only systems at equilibrium are stable
D) Disorganized energy
E) Both A and B are correct
Ans B
32) Systems far from equilibrium are referred to as _________ systems.
A) Spontaneous
B) Dissipative
C) Critical
D) Entropic
E) Heterotropic
Ans B
33) An organism at equilbrium is said to be __________.
A) At rest
B) Dissipative
C) Organized
D) Dead
E) Dormant
Ans D
34) The following statement is made by which law of thermodynamics?
“At absolute zero the disorder of a perfect crystal approaches zero”.
A) First Law
B) Second Law
C) Third Law
D) A and B
E) All make this statement
Ans C
35) A measure of a system’s internal energy is
A) Enthalpy
B) Entropy
C) Free energy
D) Work
E) Heat
Ans A
36) In living organisms where does the increase in entropy takes place?
A) Cell
B) Surroundings
C) Either A or B
D) Entropy does not change
E) Entropy does not apply to living things
Ans B
37) How many molecules of oxygen are required to completely oxidize one mole of stearic acid
( C17H35COOH)?
A) 18
B) 9
C) 34
D) 45
E) 53
Ans E
38) Given the following ∍H values calculate the ∍H for the complete combustion of stearic
acid. ∍H (kal/mol) Compound
-211.4 C17H35COO+
0 Oxygen
-94 Carbon dioxide
-68.4 Water
A) –49 kal
B) –2096.2 kal
C) –2711.8 kal
D) 0 kal
E) 3071.8 kal
Ans C
39) Magnesium ion (Mg++) forms complexes with ATP. What would happen to the stability of
ATP if the magnesium was removed?
A) There would be no change in stability
B) The ATP would be more stable
C) The ATP would be less stable
D) The effect on stability would depend on specific conditions
E) Either A or B is correct
Ans C
40) Choose the molecule with the highest phosphate transfer potential.
A) Phosphoenolpyruvate
B) ATP
C) PPi
D) Glucose-1-phosphate
E) Carbamoyl phosphate
Ans A
41) Biogeochemical cycles are pathways driven by which of the following?
A) Nuclear
B) Solar
C) Geothermal energy
D) Tectonic movements
E) B and C
Ans E
42) Which of the following moves through a system in a biogeochemical cycle?
A) Chemical compounds
B) Heat
C) Light
D) Energy
E) All of the above
Ans E
43) In classical thermodynamics which of the following is true?
A) All systems are at or near equilibrium
B) All materials are at low concentration
C) The system is far from equilibrium
D) The systems are always open
E) A and B
Ans E
44) A Benard cell is an example of
A) A classical thermodynamic system
B) A system at equilibrium
C) A dissipative system
D) A system at uniform temperature
E) B and C
Ans C
45) The evolution of living organisms is driven by
A) Size of the energy gradient to be dissipated
B) First law of thermodynamics
C) Second law of thermodynamics
D) Attainment of equilibrium
E) A and C
Ans E
46) A process is spontaneous when
A) ∍G0 = 0
B) ∍G0 > 0
C) ∍G0 < 0
D) Energy is absorbed
E) Entropy is negative
Ans C
CHAPTER FIVE
AMINO ACIDS, PEPTIDES, AND PROTEINS
1) Which of the following is a function of proteins?
A) Defense
B) Metabolic regulation
C) Transport
D) Catalysis
E) All of the above are correct
Ans E
2) The term protein refers to amino acid polymers with greater than ________amino acids.
A) 10
B) 20
C) 50
D) 70
E) 90
Ans C
3) Which of the following is a nonstandard amino acid?
A) Glycine
B) Cysteine
C) 5-Hydroxyproline
D) Valine
E) Alanine
Ans C
4) Which of the following is a heterocyclic amino acid?
A) Alanine
B) Valine
C) Proline
D) Tyrosine
E) Cystine
Ans C
5) Which of the following is not a class of amino acid?
A) Nonpolar and neutral
B) Polar and neutral
C) Acidic
D) Basic
E) Asymmetric
Ans E
6) Which of the following amino acids lacks a center of asymmetry?
A) Alanine
B) Glycine
C) Valine
D) Isoleucine
E) Aspartic acid
Ans B
7) Given the following pK’s what is the principal form of serine at pH
5? pKa1 = 2.21 pKa2 = 9.15
A)
B)
C)
D)
E)
Ans E
8) Given the following pKa’s the isoelectric point of serine is ________.
pK1 = 2.21 pK2 = 9.15
A) 2.21
B) 5.68
C) 9.15
D) 6.62
E)11.36
Ans B
9) Consider the following dipeptide. Which letter indicates a peptide bond
A) A
B) B
C) C
D) D
E) E
Ans C
10) The amino acid sequence of a polypeptide is referred to as ________structure.
A) Primary
B) Secondary
C) Tertiary
D) Quaternary
E) Peptide
Ans A
11) The overall three-dimensional structure of a polypeptide is referred to as _________
structure.
A) Primary
B) Secondary
C) Tertiary
D) Quaternary
E) Peptide
Ans C
12) Invariant amino acids in a protein are presumed:
A) To be unimportant in the structure and function of the protein
B) To be essential to the structure and function of the protein
C) Always to occur at the beginning of the amino acid sequence of an
enzyme D) Always to occur at the end of the amino acid sequence of an
enzyme E) To be part of the prosthetic group.
Ans B
13) Ε-pleated sheets are associated with what level of protein structure?
A) Primary
B) Secondary
C) Tertiary
D) Quaternary
E) Superquaternary
Ans B
14) Which of the following amino acids would foster an Δ-helix?
A) Glycine
B) Alanine
C) Proline
D) Tyrosine
E) Serine
Ans B
15) The Greek key is associated with which of the following?
A) Δ-helix
B) Parallel Ε-pleated sheets
C) Antiparallel Ε-pleated sheets
D) Disulfide bridges
E) Salt bridges
Ans C
16) Which of the following interactions do not stabilize tertiary structure?
A) Hydrophobic interactions
B) Electrostatic interactions
C) Hydrogen bonds
D) Covalent bonds
E) None of the above
Ans E
17) Detergents denature proteins by disrupting which of the following?
A) Hydrogen bonds
B) Disulfide bridges
C) Hydrophobic interactions
D) Salt bridges
E) Both A and B are correct
Ans C
18) Fibrous proteins typically have large amounts of:
A) Δ-Helix
B) Ε-Pleated sheets
C) Disulfide bridges
D) Salt bridges
E) Both A and B are correct
Ans E
19) The identity and arrangement of amino acids on the surface of a globular protein are
important because they may:
A) Interact to form specific binding cavities
B) Stabilize the tertiary structure of the protein
C) Bind regulatory molecules
D) Both A and C are correct
E) All of the above are correct
Ans E
20) Which of the following statements regarding cooperative binding is true?
A) Two or more proteins aid the binding of a ligand.
B) The binding of one ligand aids the binding of a second ligand
C) The folding of part of a protein aids in the folding of the remainder of the protein
D) All proteins engage in cooperative binding
E) The binding of a cofactor to a protein aids in the binding of a
ligand. Ans B
21) Which of the following statements is true of the Bohr effect?
A) Oxygen is delivered to cells in proportion to their needs
B) Binding of protons to hemoglobin molecules facilitates the binding of
oxygen C) Metabolic waste products bond to oxyhemoglobin
D) A and B are both true
E) All of the above are true
Ans A
22) A polypeptide has a high pI value. Which of the following amino acids are likely to be
present?
A) Glycine
B) Serine
C) Valine
D) Aspartic acid
E) Arginine
Ans E
23) Structural proteins “freeze” large amounts of water. Which of the following interactions is
not likely to be involved in the binding of water?
A) Salt bridges
B) Hydrogen bonding
C) Hydrophilic interactions
D) Disulfide bridges
E) Both C and D are correct.
Ans D
24) Why is the peptide bond stronger than the ester bond?
A) Greater electronegativity of nitrogen
B) Greater electronegativity of oxygen
C) Resonance stabilization of the amide bond
D) Increased basicity of nitrogen
E) Size of the nitrogen atom compared to the oxygen atom
Ans C
25) Which of the following amino acids would be classified as a nonstandard amino acid
A) Tyrosine
B) Lysine
C) Cystine
D) Glycine
E) Arginine
Ans C
26) Given that pK1 = 2.35 and pK2 = 9.69 for alanine. What is its isoelectric point
A) 9.69
B) 2.34
C) 6.02
D) 12.03
E) 7.00
Ans C
27) When not at the terminal of a protein which of the following amino acids cannot contribute
to the PI of a protein?
A) Arginine
B) Lysine
C) Cysteine
D) Tyrosine
E) Alanine
Ans E
28) When part of a polypeptide chain other than the N-terminus, which of the following amino
acids can form a aldimines?
A) Glycine
B) Alanine
C) Proline
D) Histidine
E) Lysine
Ans E
29) Collagen is classified as which of the following types of protein?
A) Enzyme
B) Structural
C) Movement
D) Defense
E) Regulatory
Ans B
30) A prosthetic group is a :
A) Repair enzyme
B) Group other than an amino acid that is part of a protein
C) Group that generates the native form of a protein
D) Disulfide link
E) Group that reduces enzyme activity
Ans B
31) The major component of the dry weight of cells is _______.
A) Carbohydrate
B) Protein
C) Fats
D) Minerals
E) The major component will vary from organism to organism
Ans B
32) The total number of proteins that can be produced from any 10 amino acids is?
A) 1020
B) 2010
C) 100
D) 200
E) 1010
Ans B
33) Schiff bases are also referred to as:
A) Aldimines
B) Amines
C) Carbinolamines
D) Amino acids
E) Both A and C are correct
Ans A
34) Which of the following amino acids would be found in a Ε-turn?
A) Proline
B) Alanine
C) Phenylalanine
D) Lysine
E) Tyrosine
Ans A
35) Which of the following is not a function of IUPs?
A) Signal transduction
B) Transcription
C) Translation
D) Cell proliferation
E) Oxygen transport
Ans E
36) The source of energy for motor proteins in addition to ATP is:
A) NAD+
B) GTP
C) PEP
D) ADP
E) PPi
Ans B
37) Keratin is classified as which of the following types of protein?
A) Enzyme
B) Structural
C) Movement
D) Defense
E) Regulatory
Ans B
38) In which of the following mechanical properties does spider silk exceed all synthetic fibers?
A) Toughness
B) Tensile strength
C) Elasticity
D) Resilience
E) All of the above
Ans E
39) Which of the following is a hydrophobic amino acid?
A) Glycine
B) Serine
C) Lysine
D) Phenylalanine
E) Both C and D are hydrophobic
Ans E
40) A conjugated protein consists of a simple protein combined with a _________.
A) Apoprotein
B) Holoprotein
C) Prosthetic group
D) Answers B and C are correct
E) All of the above are correct
Ans C
41) Which of the following amino acids is not one of the twenty standard amino acids?
A) Glycine
B) Phenylalanine
C) Tyrosine
D) Cystine
E) Arginine
Ans D
42) How many standard amino acids are there?
A) 5
B) 17
C) 20
D) 12
E) 32
Ans C
43) How many octapeptides containing only two amino acids are possible?
A) 8
B) 148
C) 16
D) 256
E) 35
Ans D
44) Amino acid polymers with a molecular weight between several thousand and several million
Daltons are called
A) Dipeptides
B) Polypeptides
C) Proteins
D) Peptides
E) None of the above
Ans C
45) Which of the following is not a function of proteins?
A) Structural materials
B) Catalyst
C) Metabolic regulation
D) Transport
E) All of the above are functions of proteins
Ans E
46) Which of the following is a polar amino acid?
A) Phenylalanine
B) Tyrosine
C) Methionine
D) Tryptophan
E) Proline
Ans B
CHAPTER EIGHT
CARBOHYDRATE METABOLISM
1) Both glycogenesis and glycogenolysis are controlled primarily by the interplay between the
two hormones insulin and ________.
A) Glycogen synthetase
B) Glucagon
C) Fructose kinase
D) Glucose hydrolyase
E) Pentose kinase
Ans B
2) Hexokinase D is found in the _______.
A) Kidney
B) Liver
C) Heart
D) Muscle
E) Intestine
Ans B
3) An enzyme family called the _________ catalyzes the phosphorylation of hexoses in the
body.
A) Hexolysases
B) Phosphorolysases
C) Hexokinases
D) Glucokinases
E) Phosphofructokinases
Ans C
4) The conversion of glucose-1-phosphate to UDP-glucose has a ∍G0’ near zero. Which of the
following reactions is coupled with the above reaction to drive it to completion?
A) Hydrolysis of PPi
B) Hydrolysis of ATP
C) Hydrolysis of ADP
D) Hydrolysis of UDP
E) Hydrolysis of UTP
Ans A
5) Which of the following is required for the conversion of UDP-glucose to glycogen?
A) Glycogen synthase
B) Branching enzyme
C) Glucose phosphorlyase
D) Debranching enzyme
E) Both A and B are correct
Ans E
6) A glycogen molecule that has been degraded to its branch points is called
A) Dextrin
B) Glucose
C) Amylose
D) Limit dextrin
E) Both A and B are correct
Ans D
7) Regulation of glycolysis involves all of the following except
A) Insulin
B) Glucagon
C) SREBP1c
D) AMPK
E) None of the above
Ans E
8) The binding of insulin to receptors on the surface of muscle cells stimulates which of the
following processes
A) Glycogenolysis
B) Glycogenesis
C) Release of ATP
D) Formation of cyclic AMP
E) Release of glucagon
Ans B
9) Under stressful conditions epinephrine is released from the adrenal medulla. The release of
epinephrine has which of the following effects on glucose metabolism?
A) Glycogenolysis is stimulated
B) Glycogenesis is inhibited
C) Adenylate cyclase is activated
D) Both A and B are correct
E) All of the above are correct
Ans E
10) Phosphorylase kinase
A) Converts inactive phosphorylase to active phosphorylase
B) Converts active phosphorylase to inactive phosphorylase
C) Phosphorylates glycogen synthase
D) Convets ADP to ATP
E) Both B and C are correct
Ans A
11) Cori’s disease is caused by
A) Lack of insulin
B) Lack of phospholylase b
C) Lack of glucagons
D) A deficiency of debranching enzyme
E) Deficient chromium receptors on the cell surface
Ans D
12) Which of the following activates phosphoprotein phosphatase?
A) Insulin
B) Epinephrine
C) Glucagon
D) ATP
E) Both A and B are correct
Ans A
13) Glucose-6-phosphate is a substrate in which of the following processes?
A) Gluconeogenesis
B) Glycolysis
C) Photosynthesis
D) Glycogenolysis
E) Both A and B are correct
Ans E
14) Fructose-2,6-bisphosphate
A) Is an indicator of high cellular glucose concentration
B) Is formed by PFK-1
C) Activates aldolase
D) Both A and B are correct
E) All of the above are correct
Ans A
15) The Embden-Myerhof pathway is also referred to as
A) Gluconeogenesis
B) Glycogenolysis
C) Glycolysis
D) Glycogenesis
E) Citric acid cycle
Ans C
16) In glycolysis, net ________ moles of ATP are produced per mole of glucose consumed.
A) 1
B) 2
C) 3
D) 4
E) 5
Ans B
17) In glycolysis ________ moles of NADH are produced per mole of glucose consumed
A) 1
B) 2
C) 3
D) 4
E) 5
Ans B
18) The presence of which of the following molecules indicates that the cell has sufficient energy
reserves?
A) ATP
B) Citrate
C) ADP
D) Fructose-1,6-biphosphate
E) Both A and B are correct
Ans E
19) Which of the following enzymes is an oxidoreductase?
A) Aldolase
B) Triose phosphate isomerase
C) Glyceraldehyde-3-phosphate dehdyrogenase
D) Phosphofructokinase
E) Phosphoglucoisomerase
Ans C
20) The first reaction in the oxidative phase of the pentose phosphate pathway is catalyzed by
A) Ribulose-5-phosphate dehydrogenase
B) Transketolase
C) Glucose-6-phosphatase
D) Glucose-6-phosphate dehydrogenase
E) Hexokinase
Ans D
21) Which of the following enzymes catalyzes an irreversible process?
A) Pyruvate kinase
B) Aldolase
C) Enolase
D) Phosphoglycerate mutase
E) Glyceraldehyde-3-phosphate dehydrogenase
Ans A
22) In anaerobic organisms pyruvate is used to regenerate cellular ________.
A) NADP+
B) FADH
C) FAD
D) NAD+
E) ADP
Ans D
23) Allosteric regulation of which of the following enzymes is important in the regulation of
glycolysis?
A) Hexokinase
B) PFK-1
C) Pyruvate kinase
D) Both A and C are correct
E) All of the above are correct
Ans E
24) Gluconeogenesis occurs primarily in the
A) Brain
B) Muscle
C) Liver
D) Heart
E) Pancreas
Ans C
25) Which of the following molecules can be used to synthesize glucose via gluconeogenesis?
A) Lactate
B) Pyruvate
C) Glycerol
D) Keto acids
E) All of the above are correct
Ans E
26) Which of the following is the most important glucogenic amino acid?
A) Aspartate
B) Alanine
C) Glycine
D) Glutamate
E) All are equally important
Ans B
27) Gluconeogenesis is stimulated by high concentrations of which of the following
compounds?
A) Lactate
B) Glycerol
C) Amino acid
D) Both A and B are correct
E) All of the above are correct
Ans E
28) Which of the following is an oxidizing agent in fermentation?
A) Lactate
B) Glucose
C) NADH
D) Pyruvate
E) ADP
Ans D
29) In addition to glucose which of the following sugars are important in the human diet?
A) Fructose
B) Galactose
C) Mannose
D) Sucrose
E) Both A and D are correct
Ans D
30) Intermediates in the nonoxidative phase of the pentose phosphate pathway include all of the
following except
A) Dihydroxyacetone phosphate
B) Sedoheptulose-7-phosphate
C) Fructose-6-phosphate
D) Xylulose-5-phosphate
E) Erythrose-4-phosphate
Ans A
31) The use of a highly exergonic reaction in the beginning of a catabolic pathway is referred to
as
A) Bioactivation
B) Turbo design
C) Activation
D) Glycolysis
E) Both A and C are correct
Ans B
32) Aldol cleavage of which of the following sugars will produce one mole each of
dihydroxyacetone and glyceraldehyde?
A) Fructose
B) Glucose
C) Ribose
D) Maltose
E) Trehalose
Ans A
33) Which of the following is a second messenger in glycogenolysis?
A) Glucagon
B) Insulin
C) Glucose
D) ATP
E) cAMP
Ans E
34) In animals excess glucose is converted into its storage form ________
A) Starch
B) Chitin
C) Glycogen
D) Amylose
E) Amylopectin
Ans C
35) The major carbohydrate fuel for most organisms is
A) Glucose
B) Fructose
C) Ribose
D) Sucrose
E) All of the above
Ans A
36) Which of the following enzymes is not required in gluconeogenesis?
A) Phosphoenolpyruvate carboxekinase
B) Phosphofructokinase
C) Pyruvate kinase (also in glycolysis)
D) Fructose-1,6-bisphosphatase
E) Pyruvate carboxylase
Ans B (wrong answer B&C)
37) The final product of glycolysis is
A) Dihydroxyacetone phosphate
B) Pyruvate
C) Ethanol
D) Acetyl-CoA
E) Acetaldehyde
Ans B
38) The principal products of the pentose phosphate pathway include
A) NADH
B) NADPH
C) ATP
D) Ribose-5-phosphate
E) Both B and D are correct
Ans E
39) Flux of which of the following sugars into the glycolytic pathway is essentially unregulated.
A) Glucose
B) Fructose
C) Glucose-1-phosphate
D) Both A and C are correct
E) None of the above are correct
Ans B
40) Conversion of fructose-6-phosphate to fructose-1,6-bisphosphate has two purposes. One is
the commitment of the molecule to glycolysis, the second is
A) Raising the free energy of the system
B) Making possible the formation of a second mole of ATP
C) Preventing the cleavage products of the next step from diffusing out of the cell
D) Preventing the reverse reaction
E) Enolization of the product
Ans C
41) Which of the following enzymes will catalyze the first committed step in glycolysis
A) Phosphofructoisomeras
B) Aldolase
C) Triose phosphate isomerase
D) Phosphofructokinase 1
E) Phosphoglucooisomerase
Ans D
42) The Crabtree effect in yeast is
A) Fermentation of glucose
B) Repression of aerobic metabolism by glucose
C) Repression of glycolysis by oxygen
D) Repression of glucose metabolism by ethyl alcohol
E) Fermentation of ethyl alcohol
Ans B
43) The Pasteur Effect is
A) Fermentation of glucose
B) Repression of aerobic metabolism by glucose
C) Repression of glycolysis by oxygen
D) Repression of glucose metabolism by ethyl alcohol
E) Fermentation of ethyl alcohol
Ans C
44) A diauxic shift is
A) A significant change in gene expression
B) Shifting from aerobic to anerobic respiration
C) Shifting from anerobic to aerobic respiration
D) Change in composition of microbes in a sample
E) Change in the amount of ATP used to ferment glucose
Ans A
45) The phosphorolation of glucose when it enters a cell accomplishes which of the following.