Molecular Biology Exam 2 UPDATED
ACTUAL Questions and CORRECT
Answers
An enzyme
A) decreases the rate of a reaction.
B) binds substrates in a manner that facilitates the formation of product.
C) changes the position of the equilibrium of the reaction.
D) does not change the rate at which the equilibrium is achieved.
E) is always a protein. - CORRECT ANSWER - B) binds substrates in a manner that
facilitates the formation of product.
The site on an enzyme that will bind the substrate is called the
A) prosthetic group.
B) catalyst.
C) active site.
D) metastable site.
E) activation site. - CORRECT ANSWER - C) active site.
Which of the following is an example of a prosthetic group?
A) a zinc ion
B) a glycine residue
C) a polypeptide chain
D) a nickel catalyst
E) carboxypeptidase A - CORRECT ANSWER - A) a zinc ion
,Which of the following is an enzyme?
A) iron
B) histidine
C) carboxypeptidase A
D) ATP
E) N-acetylmuramic acid - CORRECT ANSWER - C) carboxypeptidase A
An enzyme is active in the stomach of an animal but quickly loses its activity when it leaves the
stomach. This example illustrates that enzymes are
A) specific to the organs in which they are produced.
B) inactivated by movement.
C) sensitive to changes in pH.
D) inactivated by inhibitors in the small intestine.
E) consumed by the quantities of substrate in the small intestine. - CORRECT ANSWER -
C) sensitive to changes in pH.
A sick person often has a fever, which can inhibit the growth of bacteria because
A) bacteria reproduce more rapidly at higher body temperature.
B) enzymes do not function as well at temperatures other than the optimal temperature.
C) the higher temperature increases the activity of lyases.
D) sweating removes prosthetic groups from biological enzymes.
E) fever blocks synthesis of proteins in the bacterial nucleus. - CORRECT ANSWER - B)
enzymes do not function as well at temperatures other than the optimal temperature.
,The equation AB + H2O → A + B would be catalyzed by which of the following classes of
enzymes?
A) oxidoreductases
B) transferases
C) hydrolases
D) ligases
E) isomerases - CORRECT ANSWER - C) hydrolases
The equation A-PO4 + B → A + B-PO4 would be catalyzed by which of the following classes of
enzymes?
A) transferases
B) oxidoreductases
C) hydrolases
D) ligases
E) isomerases - CORRECT ANSWER - A) transferases
Substrate activation may involve
A) a change in enzyme conformation induced by substrate binding.
B) accepting protons from the enzyme.
C) formation of temporary covalent bonds.
D) donation of protons to the enzyme.
E) all of the above - CORRECT ANSWER - E) all of the above
An enzyme influences the structure of which of the following?
A) substrate
, B) product
C) transition state
D) cofactor
E) intermediate - CORRECT ANSWER - C) transition state
A competitive inhibitor will affect the ________ of an enzymatic reaction.
A) Km
B) Vmax
C) S
D) P
E) both choices A and B - CORRECT ANSWER - A) Km
A noncompetitive inhibitor will affect the ________ of an enzymatic reaction.
A) Km
B) Vmax
C) S
D) P
E) both choices A and B - CORRECT ANSWER - B) Vmax
Mixed type inhibitors will affect the ________ of an enzymatic reaction.
A) Km
B) Vmax
C) S
D) P
E) both choices A and B - CORRECT ANSWER - E) both choices A and B
ACTUAL Questions and CORRECT
Answers
An enzyme
A) decreases the rate of a reaction.
B) binds substrates in a manner that facilitates the formation of product.
C) changes the position of the equilibrium of the reaction.
D) does not change the rate at which the equilibrium is achieved.
E) is always a protein. - CORRECT ANSWER - B) binds substrates in a manner that
facilitates the formation of product.
The site on an enzyme that will bind the substrate is called the
A) prosthetic group.
B) catalyst.
C) active site.
D) metastable site.
E) activation site. - CORRECT ANSWER - C) active site.
Which of the following is an example of a prosthetic group?
A) a zinc ion
B) a glycine residue
C) a polypeptide chain
D) a nickel catalyst
E) carboxypeptidase A - CORRECT ANSWER - A) a zinc ion
,Which of the following is an enzyme?
A) iron
B) histidine
C) carboxypeptidase A
D) ATP
E) N-acetylmuramic acid - CORRECT ANSWER - C) carboxypeptidase A
An enzyme is active in the stomach of an animal but quickly loses its activity when it leaves the
stomach. This example illustrates that enzymes are
A) specific to the organs in which they are produced.
B) inactivated by movement.
C) sensitive to changes in pH.
D) inactivated by inhibitors in the small intestine.
E) consumed by the quantities of substrate in the small intestine. - CORRECT ANSWER -
C) sensitive to changes in pH.
A sick person often has a fever, which can inhibit the growth of bacteria because
A) bacteria reproduce more rapidly at higher body temperature.
B) enzymes do not function as well at temperatures other than the optimal temperature.
C) the higher temperature increases the activity of lyases.
D) sweating removes prosthetic groups from biological enzymes.
E) fever blocks synthesis of proteins in the bacterial nucleus. - CORRECT ANSWER - B)
enzymes do not function as well at temperatures other than the optimal temperature.
,The equation AB + H2O → A + B would be catalyzed by which of the following classes of
enzymes?
A) oxidoreductases
B) transferases
C) hydrolases
D) ligases
E) isomerases - CORRECT ANSWER - C) hydrolases
The equation A-PO4 + B → A + B-PO4 would be catalyzed by which of the following classes of
enzymes?
A) transferases
B) oxidoreductases
C) hydrolases
D) ligases
E) isomerases - CORRECT ANSWER - A) transferases
Substrate activation may involve
A) a change in enzyme conformation induced by substrate binding.
B) accepting protons from the enzyme.
C) formation of temporary covalent bonds.
D) donation of protons to the enzyme.
E) all of the above - CORRECT ANSWER - E) all of the above
An enzyme influences the structure of which of the following?
A) substrate
, B) product
C) transition state
D) cofactor
E) intermediate - CORRECT ANSWER - C) transition state
A competitive inhibitor will affect the ________ of an enzymatic reaction.
A) Km
B) Vmax
C) S
D) P
E) both choices A and B - CORRECT ANSWER - A) Km
A noncompetitive inhibitor will affect the ________ of an enzymatic reaction.
A) Km
B) Vmax
C) S
D) P
E) both choices A and B - CORRECT ANSWER - B) Vmax
Mixed type inhibitors will affect the ________ of an enzymatic reaction.
A) Km
B) Vmax
C) S
D) P
E) both choices A and B - CORRECT ANSWER - E) both choices A and B
