Page |1
BioChem Quizes 6,7,8 Questions and
Correct Answers/ Latest Update / Already
Graded
1) A reaction has an equilibrium constant, Keq, of 50. When performed
in the presence of an appropriate enzyme, the forward rate constant is
increased 20-fold. What will happen to the reverse rate constant?
a. In will decrease 20-fold.
b. It will increase 20-fold.
c. It will be unaffected.
Ans: b.
It will increase 20-fold.
-Since an enzyme does not alter the equilibrium constant, it
must catalyze both forward and reverse reactions to the same
extent.
2) For a reaction A + B C + D, the free energy is described as ΔG = ΔG° +
RTln[C][D]/[[A][B] (equation 1). When is it proper to write equation 1 as
ΔG = ΔG° + RTlnKeq?
a. Always
All rights reserved © 2025/ 2026 |
, Page |2
b. When ΔG = 0
c. When Keq = 1
Ans: b.
When ΔG = 0
-Only when ΔG = 0 is the reaction at equilibrium, and then it i s
proper to write Keq in the indicated place in the equation.
3) Which of the following statements is true regarding the role an
enzyme plays in catalysis?
a. An enzyme increases the equilibrium constant.
b. An enzyme increases the energy of the transition state so that it
breaks down more rapidly.
c. An enzyme decreases the activation energy.
Ans: c.
An enzyme decreases the activation energy.
-The activation energy barrier is lowered in the presence of an
enzyme.
4) The alteration of enzyme structure upon binding of a substrate to an
active site is referred to as:
All rights reserved © 2025/ 2026 |
, Page |3
a. enzyme denaturation.
b. enzyme inhibition.
c. induced fit.
Ans: c.
induced fit.
-The structure of the active site is altered by substrate binding
to produce an active conformation.
5) According to convention, the standard state free energy change,
ΔG°′, implies what special conditions in biochemical systems?
a. ΔG = 0
b. pH = 7
c. T = 310 K (37°C)
Ans: b.
pH = 7
-For biochemical systems, the standard state is defined as
having pH 7.
All rights reserved © 2025/ 2026 |
BioChem Quizes 6,7,8 Questions and
Correct Answers/ Latest Update / Already
Graded
1) A reaction has an equilibrium constant, Keq, of 50. When performed
in the presence of an appropriate enzyme, the forward rate constant is
increased 20-fold. What will happen to the reverse rate constant?
a. In will decrease 20-fold.
b. It will increase 20-fold.
c. It will be unaffected.
Ans: b.
It will increase 20-fold.
-Since an enzyme does not alter the equilibrium constant, it
must catalyze both forward and reverse reactions to the same
extent.
2) For a reaction A + B C + D, the free energy is described as ΔG = ΔG° +
RTln[C][D]/[[A][B] (equation 1). When is it proper to write equation 1 as
ΔG = ΔG° + RTlnKeq?
a. Always
All rights reserved © 2025/ 2026 |
, Page |2
b. When ΔG = 0
c. When Keq = 1
Ans: b.
When ΔG = 0
-Only when ΔG = 0 is the reaction at equilibrium, and then it i s
proper to write Keq in the indicated place in the equation.
3) Which of the following statements is true regarding the role an
enzyme plays in catalysis?
a. An enzyme increases the equilibrium constant.
b. An enzyme increases the energy of the transition state so that it
breaks down more rapidly.
c. An enzyme decreases the activation energy.
Ans: c.
An enzyme decreases the activation energy.
-The activation energy barrier is lowered in the presence of an
enzyme.
4) The alteration of enzyme structure upon binding of a substrate to an
active site is referred to as:
All rights reserved © 2025/ 2026 |
, Page |3
a. enzyme denaturation.
b. enzyme inhibition.
c. induced fit.
Ans: c.
induced fit.
-The structure of the active site is altered by substrate binding
to produce an active conformation.
5) According to convention, the standard state free energy change,
ΔG°′, implies what special conditions in biochemical systems?
a. ΔG = 0
b. pH = 7
c. T = 310 K (37°C)
Ans: b.
pH = 7
-For biochemical systems, the standard state is defined as
having pH 7.
All rights reserved © 2025/ 2026 |
