1. The second law of
thermodynamics essentially says
A) heat is energy
B) motion energy converts to
heat energy
C) at the atomic level,
motion is continuous
D) entropy increases
2. The energy required to
destabilize existing chemical bonds is called ____ energy.
A) activation
B) destabilization
C) kinetic
D) free
3. If DG is said to be
positive, it means
A) H is lower
B) reactants contain more
energy than the product does
C) S in the system is higher
D) products of the reaction
contain more energy than the reactants
4. Which of the following
is uncharacteristic of ATP?
A) It is formed by attaching
a phosphate group to ADP with a high-energy bond.
B) In most reactions
involving ATP, only the outer, high-energy bond is hydrolized.
C) It is a good long-term
energy storage molecule.
D) When dephosphorylated,
ATP becomes ADP.
5. The most primitive form
of metabolism is
A) glycolysis
B) oxygen-forming
photosynthesis
C) the degradation of
organic molecules with the released energy stored in ATP
D) anaerobic respiration
6. The First Law of
Thermodynamics states that energy can be
A) created
B) destroyed
C) converted
D) all of the above
E) none of the above
7. The universal energy
currency for all cells is
A) ATP
B) NAD+
C) ADP
D) enzymes
E) O2
8.Enzymes
A) make endergonic reactions
proceed spontaneously
B) lower the activation
energy of a reaction
C) are not very specific in
their choice of substrates
D) are needed in large
quantities because they are used up during catalysis
E) none of the above
9. To what category of
macromolecules do most enzymes belong?
A) carbohydrates
B) lipids
C) steroids
D) nucleic acids
E) proteins
10. NAD+ is a(n)
A) enzyme
B) coenzyme
C) active site
D) high-energy bond
E) allosteric activator
11. Which of the following
is a reduced compound?
A) CO2
B) O2
C) N2
D) NAD+
E) NADH
12. In an endergonic
reaction,
A) the reactants contain
less free energy than the products
B) the reactants contain
more free energy than the products
C) no activation energy is
required
D) catalysis cannot occur
E) substrates outnumber
enzymes
13. The energy of random
molecular motion is called
A) heat
B) free energy
C) enthalpy
D) potential energy
E) activation energy
14. The energy available
to do work in a system is called
A) entropy
B) activation energy
C) thermodynamics
D) free energy
E) heat
15. The initial steps in
breaking down glucose are called
A) nitrogen fixation
B) glycolysis
C) chemiosmosis
D) intramolecular catalysis
E) intermolecular catalysis
16. A catalyst will make a
reaction
A) stop
B) slow down
C) speed up
D) go in a different
direction
E) you can never tell
17. When molecules are
reduced they gain
A) energy
B) electrons
C) hydrogen protons
D) all of the above
E) none of the above
18. Which of the following
statements about enzymes is true?
A) some substrates can make
enzymes change shape slightly
B) all enzymes have the same
pH optimum
C) the active sites of all
enzymes have the same three-dimensional shape
D) all of the above
E) none of the above
19. Cofactors
A) break hydrogen bonds in
proteins
B) help facilitate enzyme
activity
C) increase activation
energy
D) are very rare in living
organisms
E) are linked to ATP by
high-energy bonds
20. How much energy is
released when one of the high-energy bonds in ATP is broken?
A) 730 cal/mole
B) 7.3 cal/mole
C) 7.3 kcal/mole
D) 73 kcal/mole
E) 730 kcal/mole
21. Consider the
hypothetical biochemical pathway H -- I -- J-- K-- L. Which step most likely
evolved first?
A) H -- I
B) I -- J
C) I -- H
D) J -- K
E) K -- L
22. Why do drastic changes
in the temperature or pH of a system alter enzyme activity?
A) they change the
three-dimensional shape of the enzyme
B) they disrupt hydrogen and
ionic bonds in the enzyme
C) they disrupt hydrophobic
interactions in the enzyme
D) all of the above
E) none of the above
23. The loss of an
electron by a molecule is called
A) oxidation
B) reduction
C) induced fit
D) enthalpy
E) allosteric inhibition
24. In the chemical
equation G = H - TS, the term G stands for
A) entropy
B) the reactants
C) enthalpy
D) free energy
E) the products
25. Enzyme B requires Zn2+
in order to catalyze the conversion of substrate X. The zinc is best identified
as a(n):
A) coenzyme
B) cofactor
C) substrate
D) product
E) enzyme
26. The next two questions
refer to the following chemical reaction that is catalyzed by the enzyme malic
dehydrogenase: malic acid + NAD+ -----> oxaloacetic acid + NADH + H+ delta G
= +7.1 kcal.
Which of the following
statements are true of this reaction?
A) Malic acid is reduced to
oxaloacetic acid.
B) b. The bonds within the
products are more stable than those within the substrates.
C) The reaction is
endergonic.
D) Entropy is increasing.
E) Both b and c, but not a
and d.
27. NAD+
A) is being reduced.
B) is a coenzyme.
C) is an oxidizing agent.
D) all of the above.
E) a and b, but not c.
28. In the malate
dehydrogenase reaction given above, NAD+ is a reducing agent.
A) True
B) False
29. Which of the following
must be true for a reaction to occur spontaneously?
A) delta G must be negative
B) delta H must be negative
C) delta S must be positive
D) delta G must be positive
E) b, c, and d, but not a
30. Continuing with
question 5, this reaction would occur spontaneously.
A) True
B) False
31. Redox reactions
(oxidation-reduction)
A) do not occur in living
systems
B) require the presence of
oxygen
C) involve the loss of
electrons termed oxidation
D) involve the gaining of
energy by an oxidized substance
E) both a and b
32. The actions of an
enzyme can be affected by all of the following except
A) p/PH
B) temperature
C) allosteric inhibitors
D) availability ATP
E) cofactors
33. Which of the following
are mismatched
A) anabolic reactions-expend
energy
B) reduction-gain of an
electron
C) endergonic
reaction-anabolism
D) exergonic
reaction-catabolism
E) activation energy-entropy
ANSWER
- 1. D 2. A 3. D 4. C 5. C 6. C 7. A 8. B 9. E 10. B
- 11. E 12. A 13. A 14. D 15. B 16. C 17. D 18. A 19. B 20. C
- 21. E 22. D 23. A 24. D 25. B 26. C 27. B 28. D 29. A 30. B
- 31. C 32. D 33. E
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