BICH 409 EXAM 3 QUESTIONS WITH VERIFIED
ANSWERS
The graph shown is a saturation curve vs substrate concentration for a protein. The
shape of this curve indicates:
a. Two proteins are competing for the same substrate.
b. The protein is an enzyme.
c. The protein cooperatively binds the substrate.
d. The protein has four substrate binding sites.
e. The hill coefficient n = 1. - Answers - c
Enzymes catalyze reactions by:
a. Stabilizing the substrates of the reaction.
b. Lowering the activation energy.
c. Changing the equilibrium constant to favor product formation.
d. Stabilizing the products of the reaction.
e. Converting all of the substrates into products. - Answers - b
The steady state assumption, as applied to enzyme kinetics, implies that:
a. The initial velocity is zero-order with respect to the substrate concentration.
b. The substrate concentration is equal to the Km.
c. The rate of ES formation is equal to the rate of the break down of ES.
d. The reaction is at equilibrium.
e. The Km is equal to the Ks. - Answers - c
Serine protease reaction mechanisms involve:
a. Electrostatic catalysis only.
b. General acid-base and covalent catalysis.
c. Specific acid/base catalysis only.
d. General acid/base catalysis only.
e. Covalent catalysis only. - Answers - b
A transition state analog would serve as an effective:
a. Mixed noncompetitive inhibitor
b. Allosteric inhibitor
c. Noncompetitive inhibitor
d. Competitive inhibitor
e. irreversible inhibitor - Answers - d
, An essential amino acid in the active site of RNA nuclease is:
a. Both serine and histidine are essential.
b. Cysteine.
c. Histidine.
d. Tyrosine.
e. Serine. - Answers - c
If the substrate concentration is equal to 1/3Km, then the velocity of the reaction will be:
a. Vmax/2
b. 3 Vmax
c. Vmax/3
d. None of these
e. Vmax/4 - Answers - e
The presence of a noncompetitive inhibitor:
a. leads to a decrease in the observed Vmax.
b. leads to a decrease in Km and Vmax.
c. leads to an increase in Km without affecting Vmax.
d. leads to both an increase in the Vmax of the reaction and an increase in the Km.
e. increases the steady state concentration of ES. - Answers - a
For an enzymatic reaction, if the substrate concentration is equal to 1/4Km, then the
velocity of the reaction will be:
a. Vmax/4
b. Vmax/5
c. 4 Vmax
d. None of these
e. Vmax/3 - Answers - b
Which of the enzymes listed above requires Zn2+ as a cofactor?
a. Carbonic Anhydrase
b. Liver Alcohol Dehydrogenase
c. Elastase
d. All of these
e. RNA Nuclease - Answers - a
Which of the following reactions would have a rate constant with units of s-1?
a. None of these
b. A+B --> P
ANSWERS
The graph shown is a saturation curve vs substrate concentration for a protein. The
shape of this curve indicates:
a. Two proteins are competing for the same substrate.
b. The protein is an enzyme.
c. The protein cooperatively binds the substrate.
d. The protein has four substrate binding sites.
e. The hill coefficient n = 1. - Answers - c
Enzymes catalyze reactions by:
a. Stabilizing the substrates of the reaction.
b. Lowering the activation energy.
c. Changing the equilibrium constant to favor product formation.
d. Stabilizing the products of the reaction.
e. Converting all of the substrates into products. - Answers - b
The steady state assumption, as applied to enzyme kinetics, implies that:
a. The initial velocity is zero-order with respect to the substrate concentration.
b. The substrate concentration is equal to the Km.
c. The rate of ES formation is equal to the rate of the break down of ES.
d. The reaction is at equilibrium.
e. The Km is equal to the Ks. - Answers - c
Serine protease reaction mechanisms involve:
a. Electrostatic catalysis only.
b. General acid-base and covalent catalysis.
c. Specific acid/base catalysis only.
d. General acid/base catalysis only.
e. Covalent catalysis only. - Answers - b
A transition state analog would serve as an effective:
a. Mixed noncompetitive inhibitor
b. Allosteric inhibitor
c. Noncompetitive inhibitor
d. Competitive inhibitor
e. irreversible inhibitor - Answers - d
, An essential amino acid in the active site of RNA nuclease is:
a. Both serine and histidine are essential.
b. Cysteine.
c. Histidine.
d. Tyrosine.
e. Serine. - Answers - c
If the substrate concentration is equal to 1/3Km, then the velocity of the reaction will be:
a. Vmax/2
b. 3 Vmax
c. Vmax/3
d. None of these
e. Vmax/4 - Answers - e
The presence of a noncompetitive inhibitor:
a. leads to a decrease in the observed Vmax.
b. leads to a decrease in Km and Vmax.
c. leads to an increase in Km without affecting Vmax.
d. leads to both an increase in the Vmax of the reaction and an increase in the Km.
e. increases the steady state concentration of ES. - Answers - a
For an enzymatic reaction, if the substrate concentration is equal to 1/4Km, then the
velocity of the reaction will be:
a. Vmax/4
b. Vmax/5
c. 4 Vmax
d. None of these
e. Vmax/3 - Answers - b
Which of the enzymes listed above requires Zn2+ as a cofactor?
a. Carbonic Anhydrase
b. Liver Alcohol Dehydrogenase
c. Elastase
d. All of these
e. RNA Nuclease - Answers - a
Which of the following reactions would have a rate constant with units of s-1?
a. None of these
b. A+B --> P
