Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED
SOLUTIONS.
Mobilization of fat stored in adipocytes involves
A. activation of fatty acids by synthesis of acyl CoA.
B. rearrangement of fatty acids in triglycerides.
C. phosphorylation of glycerol at the expense of ATP.
D. activation of a triglyceride lipase by ADP.
E. activation of a triglyceride lipase by cAMP-dependent protein kinase - ANSWER E
Each of the following is expected to be active during fatty acid biosynthesis EXCEPT one. Which one is
the EXCEPTION?
A. Tricarboxylic acid cycle
B. Pyruvate dehydrogenase complex
C. Amino acid catabolism
D. B-oxidation
E. Glycolysis - ANSWER D
Which of the following is NOT a property of triglycerides?
A. Energy-rich
B. Form micelles
C. Incorporation into chylomicrons
D. Contain saturated unsaturated fatty acids
E. Solvated by bile salts secreted by gall bladder - ANSWER B
What steps are repeated per two-carbon degradative cycle in fatty acid breakdown?
A. oxidation (NADP+), hydration (H2O), oxidation (NADP+), thiolysis (HS-CoA)
,Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
B. oxidation (FAD), hydration (H2O), oxidation (NAD+), thiolysis (HS-CoA)
C. reduction (NADPH), hydration (H2O), reduction (NADPH), thiolysis (HS-CoA)
D. reduction (FADH2), hydration (H2O), reduction (NADH), thiolysis (HS-CoA)
E. None of the above - ANSWER B
Free fatty acids diffuse passively out of adipose cells, but activated fatty acids (acyl CoA) are transported
into the mitochondrial matrix for degradation
A. by glycocholate.
B. by citrate.
C. as acyl CoA.
D. as acyl carnitine.
E. as phosphatidate. - ANSWER D
Ketone bodies produced as a result of fasting or diabetes can be metabolized by any of the following
EXCEPT:
A. Brain cells
B. Liver cells
C. Heart-muscle cells
D. Renal-cortex cells
E. Can be used by all of the above - ANSWER B
Which of the following statements is true concerning fatty acid synthesis and fatty acid breakdown?
A. Both are mitochondrial functions.
B. Both require phosphopantothenic acid.
C. Both exclusively require CoA as cofactor.
D. Both share common electron donors and acceptors.
E. Both share common enzymes for oxidation and reduction reactions. - ANSWER B
,Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
The pathway of extramitochondrial synthesis of even-numbered fatty acids differs from that of the
catabolism of fatty acids in that
A. malonyl CoA is an intermediate in synthesis.
B. acyl carrier protein is needed in catabolism.
C. no flavoprotein enzymes are required for catabolism.
D. propionyl CoA may serve as an intermediate in synthesis.
E. takes place in the endoplasmic reticulum. - ANSWER A
The first step in the pathway for fatty acid synthesis is catalyzed by an allosteric enzyme that is the
principal regulator of the pathway. This enzyme is
A. thiolase.
B. pyruvate carboxylase.
C. citrate synthetase.
D. acetyl CoA carboxylase.
E. pyruvate dehydrogenase. - ANSWER D
Complete hydrolysis of one mole of lecithin yields?
A. L-amino acids
B. D-monosaccharides
C. phosphatidylethanolamines
D. two fatty acids, one glycerol, one phosphoric acid and one choline residue
E. two fatty acids, one glycerol, one phosphoric acid and one cholesterol moiety - ANSWER D
Low-density lipoprotein (LDL) taken up by white blood cells that imbed in blood vessels and result in
arterial plaque (atherosclerosis) is composed of
A. 98% triglyceride.
B. 55-60% triglyceride, 10-15% cholesterol, 10-20% phospholipid, 5-10% protein.
C. 10% triglyceride, 45% cholesterol, 20% phospholipid, 25% protein.
D. 5% triglyceride, 20% cholesterol, 30% phospholipid, 45-50% protein.
, Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
E. 70% phospholipid. - ANSWER C
Gangliosides linked to Tay-Sachs disease
A. contain a phosphatidyl inositol moiety and four other sugars.
B. are synthesized from serine.
C. contain a special ether linkage.
D. are major components of the lysosome.
E. a and d. - ANSWER B
Degradation of proteins is mediated by ubiquitin, which
A. is an electron carrier (CoQ).
B. attaches to the C-terminus of proteins.
C. is a large proteolytic complex, also known as the ubiquinone.
D. is a small conserved protein tag added constitutively to all proteins.
E. marks specific proteins for degradation via multiple regulated steps. - ANSWER E
Degradation of proteins is mediated by a small protein that has been given the name ubiquitin, because
the tag is ubiquitously added to all cellular proteins as a common marker for proteasomal disposal.
A. Both the statement and the reason are correct and related.
B. Both the statement and the reason are correct but NOT related.
C. The statement is correct, but the reason is NOT.
D. The statement is NOT correct, but the reason is correct.
E. NEITHER the statement NOR the reason is correct. - ANSWER C
During amino acid catabolism, glutamate is converted to alpha-ketoglutarate and ammonium by
glutamate dehydrogenase via ________________.
A. oxidative amination
B. reductive amination
C. oxidative deamination
CORRECT AND APPROVED SOLUTIONS
Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED
SOLUTIONS.
Mobilization of fat stored in adipocytes involves
A. activation of fatty acids by synthesis of acyl CoA.
B. rearrangement of fatty acids in triglycerides.
C. phosphorylation of glycerol at the expense of ATP.
D. activation of a triglyceride lipase by ADP.
E. activation of a triglyceride lipase by cAMP-dependent protein kinase - ANSWER E
Each of the following is expected to be active during fatty acid biosynthesis EXCEPT one. Which one is
the EXCEPTION?
A. Tricarboxylic acid cycle
B. Pyruvate dehydrogenase complex
C. Amino acid catabolism
D. B-oxidation
E. Glycolysis - ANSWER D
Which of the following is NOT a property of triglycerides?
A. Energy-rich
B. Form micelles
C. Incorporation into chylomicrons
D. Contain saturated unsaturated fatty acids
E. Solvated by bile salts secreted by gall bladder - ANSWER B
What steps are repeated per two-carbon degradative cycle in fatty acid breakdown?
A. oxidation (NADP+), hydration (H2O), oxidation (NADP+), thiolysis (HS-CoA)
,Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
B. oxidation (FAD), hydration (H2O), oxidation (NAD+), thiolysis (HS-CoA)
C. reduction (NADPH), hydration (H2O), reduction (NADPH), thiolysis (HS-CoA)
D. reduction (FADH2), hydration (H2O), reduction (NADH), thiolysis (HS-CoA)
E. None of the above - ANSWER B
Free fatty acids diffuse passively out of adipose cells, but activated fatty acids (acyl CoA) are transported
into the mitochondrial matrix for degradation
A. by glycocholate.
B. by citrate.
C. as acyl CoA.
D. as acyl carnitine.
E. as phosphatidate. - ANSWER D
Ketone bodies produced as a result of fasting or diabetes can be metabolized by any of the following
EXCEPT:
A. Brain cells
B. Liver cells
C. Heart-muscle cells
D. Renal-cortex cells
E. Can be used by all of the above - ANSWER B
Which of the following statements is true concerning fatty acid synthesis and fatty acid breakdown?
A. Both are mitochondrial functions.
B. Both require phosphopantothenic acid.
C. Both exclusively require CoA as cofactor.
D. Both share common electron donors and acceptors.
E. Both share common enzymes for oxidation and reduction reactions. - ANSWER B
,Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
The pathway of extramitochondrial synthesis of even-numbered fatty acids differs from that of the
catabolism of fatty acids in that
A. malonyl CoA is an intermediate in synthesis.
B. acyl carrier protein is needed in catabolism.
C. no flavoprotein enzymes are required for catabolism.
D. propionyl CoA may serve as an intermediate in synthesis.
E. takes place in the endoplasmic reticulum. - ANSWER A
The first step in the pathway for fatty acid synthesis is catalyzed by an allosteric enzyme that is the
principal regulator of the pathway. This enzyme is
A. thiolase.
B. pyruvate carboxylase.
C. citrate synthetase.
D. acetyl CoA carboxylase.
E. pyruvate dehydrogenase. - ANSWER D
Complete hydrolysis of one mole of lecithin yields?
A. L-amino acids
B. D-monosaccharides
C. phosphatidylethanolamines
D. two fatty acids, one glycerol, one phosphoric acid and one choline residue
E. two fatty acids, one glycerol, one phosphoric acid and one cholesterol moiety - ANSWER D
Low-density lipoprotein (LDL) taken up by white blood cells that imbed in blood vessels and result in
arterial plaque (atherosclerosis) is composed of
A. 98% triglyceride.
B. 55-60% triglyceride, 10-15% cholesterol, 10-20% phospholipid, 5-10% protein.
C. 10% triglyceride, 45% cholesterol, 20% phospholipid, 25% protein.
D. 5% triglyceride, 20% cholesterol, 30% phospholipid, 45-50% protein.
, Biochem Test Bank 3 WITH 132
CORRECT AND APPROVED SOLUTIONS
E. 70% phospholipid. - ANSWER C
Gangliosides linked to Tay-Sachs disease
A. contain a phosphatidyl inositol moiety and four other sugars.
B. are synthesized from serine.
C. contain a special ether linkage.
D. are major components of the lysosome.
E. a and d. - ANSWER B
Degradation of proteins is mediated by ubiquitin, which
A. is an electron carrier (CoQ).
B. attaches to the C-terminus of proteins.
C. is a large proteolytic complex, also known as the ubiquinone.
D. is a small conserved protein tag added constitutively to all proteins.
E. marks specific proteins for degradation via multiple regulated steps. - ANSWER E
Degradation of proteins is mediated by a small protein that has been given the name ubiquitin, because
the tag is ubiquitously added to all cellular proteins as a common marker for proteasomal disposal.
A. Both the statement and the reason are correct and related.
B. Both the statement and the reason are correct but NOT related.
C. The statement is correct, but the reason is NOT.
D. The statement is NOT correct, but the reason is correct.
E. NEITHER the statement NOR the reason is correct. - ANSWER C
During amino acid catabolism, glutamate is converted to alpha-ketoglutarate and ammonium by
glutamate dehydrogenase via ________________.
A. oxidative amination
B. reductive amination
C. oxidative deamination
