1. Which of the following reactions could be
coupled to the reaction ATP + H2O ? ADP +
Pi (-7.3 kcal/mol)? (Pi means inorganic phosphate)
a. A + Pi ? AP (+10 kcal/mol)
b. B + Pi ? BP (+8 kcal/mol)
c. CP ? C + Pi (-4 kcal/mol)
d. DP ? D + Pi (-10 kcal/mol)
e. E + Pi ? EP (+5 kcal/mol)
Copyright © 2004 Pearson Education, Inc. publishing as Benjamin Cummings
• 2. A solution of starch at room temperature
does not decompose rapidly to a sugar
solution because
– a. the starch solution has less free energy than
the sugar solution.
– b. the hydrolysis of starch to sugar is endergonic.
– c. the activation energy barrier cannot be
surmounted in most of the starch molecules.
– d. starch cannot be hydrolyzed in the presence
of so much water.
– e. starch hydrolysis is nonspontaneous.
3. Which curve was
generated using
an enzyme taken
from a bacterium
that lives in hot
springs at
temperatures of
70ºC or higher?
–
–
–
–
–
A. curve 1
B. curve 2
C. curve 3
D. curve 4
E. curve 5
• 4. Increasing the substrate concentration in
an enzymatic reaction may overcome which
of the following?
–
–
–
–
–
a. denaturization of the enzyme
b. allosteric inhibition
c. competitive inhibition
d. noncompetitive inhibition
e. insufficient cofactors
• 5. Which of the following represents the ∆G
of the reaction?
–
–
–
–
–
a
b
c
d
e
• 6. Which of the following would be the same in an
enzyme-catalyzed or -uncatalyzed reaction?
–
–
–
–
–
a
b
c
d
e
• 7. Assume that the reaction has a ∆G of -5.6
kcal/mol. Which of the following would most likely
be true?
– a. The reaction could be coupled to power an
endergonic reaction with a ∆G of +6.2
kcal/mol.
– b. The reaction could be coupled to power an
exergonic reaction with a ∆G of +8.8 kcal/mol.
– c. The reaction would result in a decrease in
entropy (S) and an increase in the total
energy content (H) of the system.
– d. The reaction would result in an increase in
entropy (S) and a decrease in the total energy
content (H) of the system.
– e. The reaction would result in products (C +
D) with a greater free-energy content than in
the initial reactants (A + B).
• 8. In the following branched metabolic
pathway, a dotted arrow with a minus sign
symbolizes inhibition of a metabolic step by
an end product:
Which reaction would prevail if both Q and S
were present in the cell in high
concentrations?
a.
L→M
b.
c.
d.
e.
M→O
L→N
O→P
R→S
Answers to Chapter 8 practice quiz
• 1. E
• 2. C
• 3. C
• 4. C
• 5. D
• 6. D
• 7. D
• 8. C