BIOCHEM CHAPTER 19 EXAM 19
21. A mutation in the active site of succinyl CoA synthetase where His is converted
to a lysine
would result in which?
increased stable folding
the loss of a succinyl phosphate intermediate
the loss of a positive-charged amino acid necessary for catalysis
All of the above
None of the above - CORRECT ANSWER-B) the loss of a succinyl
phosphate intermediate
22. What molecule initiates the citric acid cycle by reacting with oxaloacetate?
pyruvate
acetyl CoA
oxaloacetate
All of the above.
None of the above. - CORRECT ANSWER-B) acetyl CoA
23. In muscle, the enzyme used to catalyze a substrate-level phosphorylation is:
nucleoside triphosphate transferase.
protein kinase C.
GTP kinase.
succinyl CoA synthetase.
ATP-GTP transferase. - CORRECT ANSWER-D) succinyl CoA synthetase.
24. The direct channeling of proteins from one enzyme to the next will happen in
a(n):
protein complex.
metabolon.
linker coenzyme.
cell with sufficient available water.
electron acceptor. - CORRECT ANSWER-B) metabolon.
25. Which of the following vitamins are precursors to coenzymes that are necessary
for the
formation of succinyl CoA from α-ketoglutarate?
thiamine, riboflavin, niacin, lipoic acid, and pantothenic acid
thiamine, riboflavin, niacin, lipoic acid, pantothenic acid, and biotin
thiamine, riboflavin, niacin, and biotin
thiamine, riboflavin, and lipoic acid
None of the above. - CORRECT ANSWER-A) thiamine, riboflavin, niacin,
lipoic acid, and pantothenic acid
, 26. Isomerization of citrate is catalyzed by:
citrate synthase.
aldolase.
α-ketogutarate dehydrogenase.
D)--- - CORRECT ANSWER-Answer is D 19.2
27. Formation of citrate from acetyl CoA and oxaloacetate is a(n) _________
reaction.
oxidation
reduction
condensation
ligation
None of the above. - CORRECT ANSWER-C) condensation
28. What is/are the chemical change(s) involved in the conversion of citrate into
isocitrate?
hydration followed by dehydration
oxidation
oxidation followed by reduction
dehydration followed by hydration
A and B - CORRECT ANSWER-D) dehydration followed by hydration
29. In which reaction is ATP directly formed in the citric acid cycle?
conversion of succinyl CoA to succinate
decarboxylation of α-ketoglutarate
conversion of isocitrate to α-ketoglutarate
All of the above.
None of the above. - CORRECT ANSWER-A) conversion of succinyl CoA to
succinate
30. In which step of the citric acid cycle is FADH2 formed?
the conversion of succinate to malate
the conversion of succinate to oxaloacetate
the conversion of succinate to fumarate
the conversion of malate to oxaloacetate
None of the above. - CORRECT ANSWER-C) the conversion of succinate to
fumarate
31. Which of these compounds is oxidized by a multienzyme complex that requires
five different
coenzymes?
A)
-O2C C
H
C CO2
-
21. A mutation in the active site of succinyl CoA synthetase where His is converted
to a lysine
would result in which?
increased stable folding
the loss of a succinyl phosphate intermediate
the loss of a positive-charged amino acid necessary for catalysis
All of the above
None of the above - CORRECT ANSWER-B) the loss of a succinyl
phosphate intermediate
22. What molecule initiates the citric acid cycle by reacting with oxaloacetate?
pyruvate
acetyl CoA
oxaloacetate
All of the above.
None of the above. - CORRECT ANSWER-B) acetyl CoA
23. In muscle, the enzyme used to catalyze a substrate-level phosphorylation is:
nucleoside triphosphate transferase.
protein kinase C.
GTP kinase.
succinyl CoA synthetase.
ATP-GTP transferase. - CORRECT ANSWER-D) succinyl CoA synthetase.
24. The direct channeling of proteins from one enzyme to the next will happen in
a(n):
protein complex.
metabolon.
linker coenzyme.
cell with sufficient available water.
electron acceptor. - CORRECT ANSWER-B) metabolon.
25. Which of the following vitamins are precursors to coenzymes that are necessary
for the
formation of succinyl CoA from α-ketoglutarate?
thiamine, riboflavin, niacin, lipoic acid, and pantothenic acid
thiamine, riboflavin, niacin, lipoic acid, pantothenic acid, and biotin
thiamine, riboflavin, niacin, and biotin
thiamine, riboflavin, and lipoic acid
None of the above. - CORRECT ANSWER-A) thiamine, riboflavin, niacin,
lipoic acid, and pantothenic acid
, 26. Isomerization of citrate is catalyzed by:
citrate synthase.
aldolase.
α-ketogutarate dehydrogenase.
D)--- - CORRECT ANSWER-Answer is D 19.2
27. Formation of citrate from acetyl CoA and oxaloacetate is a(n) _________
reaction.
oxidation
reduction
condensation
ligation
None of the above. - CORRECT ANSWER-C) condensation
28. What is/are the chemical change(s) involved in the conversion of citrate into
isocitrate?
hydration followed by dehydration
oxidation
oxidation followed by reduction
dehydration followed by hydration
A and B - CORRECT ANSWER-D) dehydration followed by hydration
29. In which reaction is ATP directly formed in the citric acid cycle?
conversion of succinyl CoA to succinate
decarboxylation of α-ketoglutarate
conversion of isocitrate to α-ketoglutarate
All of the above.
None of the above. - CORRECT ANSWER-A) conversion of succinyl CoA to
succinate
30. In which step of the citric acid cycle is FADH2 formed?
the conversion of succinate to malate
the conversion of succinate to oxaloacetate
the conversion of succinate to fumarate
the conversion of malate to oxaloacetate
None of the above. - CORRECT ANSWER-C) the conversion of succinate to
fumarate
31. Which of these compounds is oxidized by a multienzyme complex that requires
five different
coenzymes?
A)
-O2C C
H
C CO2
-
