BIOL 334 Comparative Biochemistry Exam Questions
And Complete Answers
Which of the following statements about the nature of enzyme catalysis is correct? -
ANSWER d) An enzyme greatly accelerates reaction rates by lowering the activation
energy of a chemical reaction.
2. Which of the following statements about Michaelis-Menten enzyme kinetics is
correct? - ANSWER d) Km, the Michaelis constant, reflects the (apparent) affinity the
enzyme has for its substrate.
3. Which of the following statements about competitive inhibition of an
enzyme-catalyzed reaction is correct? - ANSWER c) The enzyme's Vmax remains
unchanged in the presence of a competitive inhibitor. d
4. Which of the following statements about allosteric enzymes is correct? - ANSWER d)
The 'native form' of an allosteric enzyme can contain non-catalytic subunits.
5. Which of the following statements about competitive inhibition of an
enzyme-catalyzed reaction is correct? - ANSWER c) Competitive inhibition can be
overcome by the addition of large amounts of substrate to a reaction.
6. Which of the following statements about Michaelis-Menten kinetics are correct? -
ANSWER e) B and D are correct
b) A low Km values indicates a high affinity of an enzyme for its substrate. c
d) The Km of an enzyme is unchanged when the enzyme's concentration is increased. e
7. Which of the statements regarding enzymes is false? - ANSWER c) Enzymes shift the
equilibrium position of a chemical reaction in favor of the product(s).
8. When [S] = KM, the velocity of an enzyme catalyzed reaction is: - ANSWER d) 0.5 x
, Vmax.
9. β-galactosidase catalyzes the hydrolysis of the disaccharide lactose to yield glucose
and galactose. What other substrate does β-galactosidase require (apart from
galactose)? - ANSWER c) H2O
10. Lactate dehydrogenase from human skeletal muscle and heart provides a good
example of: - ANSWER a) isozymes
11. The 'thermal kinetic window' corresponds to the temperature range over which an
enzyme displays: - ANSWER a) the minimal Km value for its substrate(s)
12. Any non-protein component that is absolutely required by an enzyme for it to have
catalytic activity is referred to as a: - ANSWER d) co-factor
13. In Mixed-Competitive inhibition of enzyme activity... - ANSWER b) The inhibitor can
bind to the free enzyme or the enzyme-substrate complex.
14. Which of the following statements about allosteric enzymes is false? - ANSWER c)
Allosteric effectors compete with the substrate for binding sites.
15. Q10 values for most enzymes from homeothermic (warm blooded) animal species
are approx. 2.0, whereas Q10 values for enzymes of many poikilothermic (cold blooded)
species are often much less than 2.0 (and sometimes close to 1.0). How might this help a
poikilothermic animal adapt to its environment? - ANSWER a) Metabolic processes are
not as severely influenced by changes in environmental temperature
16. Which of the following techniques or approaches has contributed to our
understanding of the structure of a metabolic pathway in a particular species? -
ANSWER e) B and D are both correct
b) 'pulse-chase' radiolabeling studies
d) annotated genome sequence information
And Complete Answers
Which of the following statements about the nature of enzyme catalysis is correct? -
ANSWER d) An enzyme greatly accelerates reaction rates by lowering the activation
energy of a chemical reaction.
2. Which of the following statements about Michaelis-Menten enzyme kinetics is
correct? - ANSWER d) Km, the Michaelis constant, reflects the (apparent) affinity the
enzyme has for its substrate.
3. Which of the following statements about competitive inhibition of an
enzyme-catalyzed reaction is correct? - ANSWER c) The enzyme's Vmax remains
unchanged in the presence of a competitive inhibitor. d
4. Which of the following statements about allosteric enzymes is correct? - ANSWER d)
The 'native form' of an allosteric enzyme can contain non-catalytic subunits.
5. Which of the following statements about competitive inhibition of an
enzyme-catalyzed reaction is correct? - ANSWER c) Competitive inhibition can be
overcome by the addition of large amounts of substrate to a reaction.
6. Which of the following statements about Michaelis-Menten kinetics are correct? -
ANSWER e) B and D are correct
b) A low Km values indicates a high affinity of an enzyme for its substrate. c
d) The Km of an enzyme is unchanged when the enzyme's concentration is increased. e
7. Which of the statements regarding enzymes is false? - ANSWER c) Enzymes shift the
equilibrium position of a chemical reaction in favor of the product(s).
8. When [S] = KM, the velocity of an enzyme catalyzed reaction is: - ANSWER d) 0.5 x
, Vmax.
9. β-galactosidase catalyzes the hydrolysis of the disaccharide lactose to yield glucose
and galactose. What other substrate does β-galactosidase require (apart from
galactose)? - ANSWER c) H2O
10. Lactate dehydrogenase from human skeletal muscle and heart provides a good
example of: - ANSWER a) isozymes
11. The 'thermal kinetic window' corresponds to the temperature range over which an
enzyme displays: - ANSWER a) the minimal Km value for its substrate(s)
12. Any non-protein component that is absolutely required by an enzyme for it to have
catalytic activity is referred to as a: - ANSWER d) co-factor
13. In Mixed-Competitive inhibition of enzyme activity... - ANSWER b) The inhibitor can
bind to the free enzyme or the enzyme-substrate complex.
14. Which of the following statements about allosteric enzymes is false? - ANSWER c)
Allosteric effectors compete with the substrate for binding sites.
15. Q10 values for most enzymes from homeothermic (warm blooded) animal species
are approx. 2.0, whereas Q10 values for enzymes of many poikilothermic (cold blooded)
species are often much less than 2.0 (and sometimes close to 1.0). How might this help a
poikilothermic animal adapt to its environment? - ANSWER a) Metabolic processes are
not as severely influenced by changes in environmental temperature
16. Which of the following techniques or approaches has contributed to our
understanding of the structure of a metabolic pathway in a particular species? -
ANSWER e) B and D are both correct
b) 'pulse-chase' radiolabeling studies
d) annotated genome sequence information
