Click here for more: Scholars nexus
BCH 3025 Exam 4 Questions with Detailed
Verified Answers
Which of the following is not required in the synthesis of fatty acids?
A) Acetyl-CoA
B) Biotin
C) HCO3- (CO2)
D) Malonyl-CoA
E) NADH
Ans: E) NADH
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 CO2 (or bicarbonate).
D) One mole of ATP is converted to ADP + Pi for each malonyl-CoA synthesized.
E) The cofactor is biotin.
Ans: B) It requires acyl carrier protein (ACP).
If malonyl-CoA is synthesized from 14CO2 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.
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
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).
Ans: D) no part of the molecule.
Which one of the following statements best applies to synthesis of fatty acids in E. coli
extracts?
A) Acyl intermediates are thioesters of a low molecular weight protein called acyl
carrier protein.
B) CO2 or HCO3- is essential.
C) Reducing equivalents are provided by NADPH.
D) The ultimate source of all the carbon atoms in the fatty acid product is acetyl-CoA.
E) All of the above
Ans: E) All of the above
In comparing fatty acid biosynthesis with β oxidation of fatty acids, which of the
following statements is incorrect?
A) A thioester derivative of crotonic acid (trans-2-butenoic acid) is an intermediate in
the synthetic path, but not in the degradative path.
B) A thioester derivative of D-β-hydroxybutyrate is an intermediate in the synthetic
path, not in the degradative path.
C) Fatty acid biosynthesis uses NADPH exclusively, whereas β oxidation uses NAD+
exclusively.
D) Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by
mitochondrial enzymes.
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
E) The condensation of two moles of acetyl-CoA in the presence of a crude extract is
more rapid in bicarbonate buffer than in phosphate buffer at the same pH; the cleavage
of acetoacetyl-CoA proceeds equally well in either buffer.
Ans: D) Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by
mitochondrial enzymes.
Which of the following is not true of the fatty acid synthase and the fatty acid β-
oxidation systems?
A) A derivative of the vitamin pantothenic acid is involved.
B) Acyl-CoA derivatives are intermediates.
C) Double bonds are oxidized or reduced by pyridine nucleotide coenzymes.
D) The processes occur in different cellular compartments.
E) The processes occur in the mitochondrial matrix.
Ans: E) The processes occur in the mitochondrial matrix.
The rate-limiting step in fatty acid synthesis is:
A) condensation of acetyl-CoA and malonyl-CoA.
B) formation 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 β-hydroxybutyryl group.
Ans: D) the reaction catalyzed by acetyl-CoA carboxylase.
Which of the following is not true of the fatty acid elongation system of vertebrate
cells?
© Get it right 2025 Getaway - Stuvia US All rights reserved
, Click here for more: Scholars nexus
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.
Ans: E) The immediate precursor of the added carbons is acetyl-CoA.
Which of the following is not true about precursors required for fatty acid synthesis
in animal cells?
A) NADPH is produced in the cytosol by the pentose phosphate pathway.
B) NADPH is produced in the nucleus by malic enzyme.
C) Acetyl-CoA is transported out of the mitochondrion via the citrate shuttle.
D) CoA is not transported across the mitochondrial membrane.
E) Malonyl-CoA is formed in the cytosol.
Ans: B) NADPH is produced in the nucleus by malic enzyme.
Which of these can be synthesized by plants but not by humans?
A) Linoleate [18:2(Δ9,12)]
B) Palmitate (16:0)
C) Phosphatidylcholine
D) Pyruvate
E) Stearate (18:0)
Ans: A) Linoleate [18:2(Δ9,12)]
© Get it right 2025 Getaway - Stuvia US All rights reserved
BCH 3025 Exam 4 Questions with Detailed
Verified Answers
Which of the following is not required in the synthesis of fatty acids?
A) Acetyl-CoA
B) Biotin
C) HCO3- (CO2)
D) Malonyl-CoA
E) NADH
Ans: E) NADH
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 CO2 (or bicarbonate).
D) One mole of ATP is converted to ADP + Pi for each malonyl-CoA synthesized.
E) The cofactor is biotin.
Ans: B) It requires acyl carrier protein (ACP).
If malonyl-CoA is synthesized from 14CO2 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.
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
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).
Ans: D) no part of the molecule.
Which one of the following statements best applies to synthesis of fatty acids in E. coli
extracts?
A) Acyl intermediates are thioesters of a low molecular weight protein called acyl
carrier protein.
B) CO2 or HCO3- is essential.
C) Reducing equivalents are provided by NADPH.
D) The ultimate source of all the carbon atoms in the fatty acid product is acetyl-CoA.
E) All of the above
Ans: E) All of the above
In comparing fatty acid biosynthesis with β oxidation of fatty acids, which of the
following statements is incorrect?
A) A thioester derivative of crotonic acid (trans-2-butenoic acid) is an intermediate in
the synthetic path, but not in the degradative path.
B) A thioester derivative of D-β-hydroxybutyrate is an intermediate in the synthetic
path, not in the degradative path.
C) Fatty acid biosynthesis uses NADPH exclusively, whereas β oxidation uses NAD+
exclusively.
D) Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by
mitochondrial enzymes.
© Get it right 2025 Getaway - Stuvia US All rights reserved
,Click here for more: Scholars nexus
E) The condensation of two moles of acetyl-CoA in the presence of a crude extract is
more rapid in bicarbonate buffer than in phosphate buffer at the same pH; the cleavage
of acetoacetyl-CoA proceeds equally well in either buffer.
Ans: D) Fatty acid degradation is catalyzed by cytosolic enzymes; fatty acid synthesis by
mitochondrial enzymes.
Which of the following is not true of the fatty acid synthase and the fatty acid β-
oxidation systems?
A) A derivative of the vitamin pantothenic acid is involved.
B) Acyl-CoA derivatives are intermediates.
C) Double bonds are oxidized or reduced by pyridine nucleotide coenzymes.
D) The processes occur in different cellular compartments.
E) The processes occur in the mitochondrial matrix.
Ans: E) The processes occur in the mitochondrial matrix.
The rate-limiting step in fatty acid synthesis is:
A) condensation of acetyl-CoA and malonyl-CoA.
B) formation 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 β-hydroxybutyryl group.
Ans: D) the reaction catalyzed by acetyl-CoA carboxylase.
Which of the following is not true of the fatty acid elongation system of vertebrate
cells?
© Get it right 2025 Getaway - Stuvia US All rights reserved
, Click here for more: Scholars nexus
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.
Ans: E) The immediate precursor of the added carbons is acetyl-CoA.
Which of the following is not true about precursors required for fatty acid synthesis
in animal cells?
A) NADPH is produced in the cytosol by the pentose phosphate pathway.
B) NADPH is produced in the nucleus by malic enzyme.
C) Acetyl-CoA is transported out of the mitochondrion via the citrate shuttle.
D) CoA is not transported across the mitochondrial membrane.
E) Malonyl-CoA is formed in the cytosol.
Ans: B) NADPH is produced in the nucleus by malic enzyme.
Which of these can be synthesized by plants but not by humans?
A) Linoleate [18:2(Δ9,12)]
B) Palmitate (16:0)
C) Phosphatidylcholine
D) Pyruvate
E) Stearate (18:0)
Ans: A) Linoleate [18:2(Δ9,12)]
© Get it right 2025 Getaway - Stuvia US All rights reserved
