BIOCHEMISTRY FINAL EXAM REVISION
QUESTIONS AND THEIR EXPECTED
ANSWERS
Which of the following is not required in the synthesis
of fatty acids?
A) Acetyl-CoA
B) Biotin
C) HC03- (C02)
D) Malony1-C0A
E) NADH
E
Which of the following is not true of the reaction
producing malonyl-CoA during fatty acid synthesis?
A) It is stimulated by citrate.
B) It requires acyl carrier protein (ACP). C) It requires
C02 (or bicarbonate).
D) One mole of ATP is converted to ADP + Pi for each
malonyl-CoA synthesized.
E) The cofactor is biotin.
B
If malonyl-CoA is synthesized from 14C02 and
unlabeled acetyl„CoA, and the labeled malonate is
then used for fatty acid synthesis, the final product
(fatty acid) will have radioactive carbon in:
A) every C.
B) every even-numbered C-atom. C) every odd-
,numbered C-atom.
D) no part of the molecule.
E) only the omega-carbon atom (farthest carbon from
C-1).
D
The rate-limiting step in fatty acid synthesis is: A)
condensation of acetyl-CoA and malonyl„CoA. B)
fonnation of acetyl-CoA from acetate.
C) formation of malonyl-CoA from malonate and
coenzyme A. D) the reaction catalyzed by acetyl-CoA
carboxylase.
E) the reduction of the acetoacetyl group to a "-
hydroxybutyryl group.
D
Which of the following is not true of the fatty acid
elongation system of vertebrate cells? A) It involves
the same four-step sequence seen in the fatty acid
synthase complex.
B) It is located in the smooth endoplasmic reticulum.
C) It produces stearoyl-CoA by the extension of
palmitoyl-CoA. D) It uses malonyl-CoA as a substrate.
E) The immediate precursor of the added carbons is
acetyl-CoA.
E
Which of these can be synthesized by plants but not
by humans?
A) Linoleate
B) Palmitate (16:0)
C) Phosphatidylcholine
D) Pyruvate
E) Stearate (18:0)
, A
Which of these statements about eicosanoid
synthesis is true?
A) An early step in the path to thromboxanes is
blocked by ibuprofen.
B) Arachidonate is derived mainly by hydrolysis of
triacylglycerols. C) Aspirin acts by blocking the
synthesis of arachidonate.
D) Plants can synthesize leukotrienes, but humans
cannot.
E) Thromboxanes are produced from arachidonate via
the "linear" path.
A
The synthesis of both glycerophospholipids and
triacylglycerols involves:
A) CDP-choline. B) CDP-diacylglycerol. C)
phosphatidate phosphatase. D) phosphatidic acid.
E) phosphoethanolamine.
D
Which of these statements about triacylglycerol
synthesis is correct? A) Humans can store more
energy in glycogen than in triacylglycerols. B) Insulin
stimulates conversion of dietary carbohydrate into
triacylglycerols.
C) It is not a hormone-sensitive process.
D) Mammals are unable to convert carbohydrates into
triacylglycerols. E) Phosphatidate is not on the
pathway of triacylglycerol synthesis.
B
A strategy that is not employed in the synthesis of
phospholipids is:
QUESTIONS AND THEIR EXPECTED
ANSWERS
Which of the following is not required in the synthesis
of fatty acids?
A) Acetyl-CoA
B) Biotin
C) HC03- (C02)
D) Malony1-C0A
E) NADH
E
Which of the following is not true of the reaction
producing malonyl-CoA during fatty acid synthesis?
A) It is stimulated by citrate.
B) It requires acyl carrier protein (ACP). C) It requires
C02 (or bicarbonate).
D) One mole of ATP is converted to ADP + Pi for each
malonyl-CoA synthesized.
E) The cofactor is biotin.
B
If malonyl-CoA is synthesized from 14C02 and
unlabeled acetyl„CoA, and the labeled malonate is
then used for fatty acid synthesis, the final product
(fatty acid) will have radioactive carbon in:
A) every C.
B) every even-numbered C-atom. C) every odd-
,numbered C-atom.
D) no part of the molecule.
E) only the omega-carbon atom (farthest carbon from
C-1).
D
The rate-limiting step in fatty acid synthesis is: A)
condensation of acetyl-CoA and malonyl„CoA. B)
fonnation of acetyl-CoA from acetate.
C) formation of malonyl-CoA from malonate and
coenzyme A. D) the reaction catalyzed by acetyl-CoA
carboxylase.
E) the reduction of the acetoacetyl group to a "-
hydroxybutyryl group.
D
Which of the following is not true of the fatty acid
elongation system of vertebrate cells? A) It involves
the same four-step sequence seen in the fatty acid
synthase complex.
B) It is located in the smooth endoplasmic reticulum.
C) It produces stearoyl-CoA by the extension of
palmitoyl-CoA. D) It uses malonyl-CoA as a substrate.
E) The immediate precursor of the added carbons is
acetyl-CoA.
E
Which of these can be synthesized by plants but not
by humans?
A) Linoleate
B) Palmitate (16:0)
C) Phosphatidylcholine
D) Pyruvate
E) Stearate (18:0)
, A
Which of these statements about eicosanoid
synthesis is true?
A) An early step in the path to thromboxanes is
blocked by ibuprofen.
B) Arachidonate is derived mainly by hydrolysis of
triacylglycerols. C) Aspirin acts by blocking the
synthesis of arachidonate.
D) Plants can synthesize leukotrienes, but humans
cannot.
E) Thromboxanes are produced from arachidonate via
the "linear" path.
A
The synthesis of both glycerophospholipids and
triacylglycerols involves:
A) CDP-choline. B) CDP-diacylglycerol. C)
phosphatidate phosphatase. D) phosphatidic acid.
E) phosphoethanolamine.
D
Which of these statements about triacylglycerol
synthesis is correct? A) Humans can store more
energy in glycogen than in triacylglycerols. B) Insulin
stimulates conversion of dietary carbohydrate into
triacylglycerols.
C) It is not a hormone-sensitive process.
D) Mammals are unable to convert carbohydrates into
triacylglycerols. E) Phosphatidate is not on the
pathway of triacylglycerol synthesis.
B
A strategy that is not employed in the synthesis of
phospholipids is:
