Page 1 of 13
lehninger principles of biochemistry, 7th
edition(chapter 6)
the role of an enzyme in an enzyme-catalyzed reaction is to:
a) bind a transition state intermediate, such that it cannot be converted back to substrate.
b) ensure that all of the substrate is converted to product.
c) ensure that the product is more stable than the substrate.
d) increase the rate at which substrate is converted into product.
e) make the free-energy change for the reaction more favorable. - answer-d
enzymes are potent catalysts because they:
a) are consumed in the reactions they catalyze.
b) are very specific and can prevent the conversion of products back to substrates.
c) drive reactions to completion while other catalysts drive reactions to equilibrium.
d) increase the equilibrium constants for the reactions they catalyze.
e) lower the activation energy for the reactions they catalyze. - answer-e
one of the enzymes involved in glycolysis, aldolase, requires zn2+ for catalysis. under conditions of zinc
deficiency, when the enzyme may lack zinc, it would be referred to as the:
a) apoenzyme.
b) coenzyme.
c) holoenzyme.
d) prosthetic group.
e) substrate. - answer-a
, Page 2 of 13
which one of the following is not among the six internationally accepted classes of enzymes?
a) hydrolases
b) ligases
c) oxidoreductases
d) polymerases
e) transferases - answer-d
which one of the following statements is true of enzyme catalysts?
a) their catalytic activity is independent of ph.
b) they are generally equally active on d and l isomers of a given substrate.
c) they can increase the equilibrium constant for a given reaction by a thousand fold or more.
d) they can increase the reaction rate for a given reaction by a thousand fold or more.
e) to be effective, they must be present at the same concentration as their substrate. - answer-d
which one of the following statements is true of enzyme catalysts?
a) they bind to substrates, but are never covalently attached to substrate or product.
b) they increase the equilibrium constant for a reaction, thus favoring product formation.
c) they increase the stability of the product of a desired reaction by allowing ionizations, resonance, and
isomerizations not normally available to substrates.
d) they lower the activation energy for the conversion of substrate to product.
e) to be effective they must be present at the same concentration as their substrates. - answer-d
which of the following statements is false?
lehninger principles of biochemistry, 7th
edition(chapter 6)
the role of an enzyme in an enzyme-catalyzed reaction is to:
a) bind a transition state intermediate, such that it cannot be converted back to substrate.
b) ensure that all of the substrate is converted to product.
c) ensure that the product is more stable than the substrate.
d) increase the rate at which substrate is converted into product.
e) make the free-energy change for the reaction more favorable. - answer-d
enzymes are potent catalysts because they:
a) are consumed in the reactions they catalyze.
b) are very specific and can prevent the conversion of products back to substrates.
c) drive reactions to completion while other catalysts drive reactions to equilibrium.
d) increase the equilibrium constants for the reactions they catalyze.
e) lower the activation energy for the reactions they catalyze. - answer-e
one of the enzymes involved in glycolysis, aldolase, requires zn2+ for catalysis. under conditions of zinc
deficiency, when the enzyme may lack zinc, it would be referred to as the:
a) apoenzyme.
b) coenzyme.
c) holoenzyme.
d) prosthetic group.
e) substrate. - answer-a
, Page 2 of 13
which one of the following is not among the six internationally accepted classes of enzymes?
a) hydrolases
b) ligases
c) oxidoreductases
d) polymerases
e) transferases - answer-d
which one of the following statements is true of enzyme catalysts?
a) their catalytic activity is independent of ph.
b) they are generally equally active on d and l isomers of a given substrate.
c) they can increase the equilibrium constant for a given reaction by a thousand fold or more.
d) they can increase the reaction rate for a given reaction by a thousand fold or more.
e) to be effective, they must be present at the same concentration as their substrate. - answer-d
which one of the following statements is true of enzyme catalysts?
a) they bind to substrates, but are never covalently attached to substrate or product.
b) they increase the equilibrium constant for a reaction, thus favoring product formation.
c) they increase the stability of the product of a desired reaction by allowing ionizations, resonance, and
isomerizations not normally available to substrates.
d) they lower the activation energy for the conversion of substrate to product.
e) to be effective they must be present at the same concentration as their substrates. - answer-d
which of the following statements is false?
