BCH 369 EXAM 4 QUESTIONS WITH
REVISED ANSWERS
The commercial herbicide Roundup inhibits chorismate synthesis in plants. Chorismate
is the precursor for the biosynthesis of aromatic amino acids. Which amino acids would
likely become essential for weeds growing in crop-fields being sprayed with Roundup
("Roundup ready")?
A) Phe, Pro, Thr B) Phe, Tyr, Trp C) Tyr, Trp, Thr D) Pro, Tyr, Phe E) Pro, Tyr, Trp -
Answer-B) Phe, Tyr, Trp
What is the product of the following transaminase reaction: arginine + α-ketoglutarate --
>
glutamate +
A) A B) B C) C D) D - Answer-D) D
Under which one of the following conditions does the biosynthesis of fatty acids in the
liver mainly
occur?
A) After ingestion of excess triacylglycerols.
, D) High carbohydrate intake.
B) Low carbohydrate intake.
E) None of the above.
C) High cholesterol intake. - Answer-D) High carbohydrate intake.
Of the molecules below, which is not used by any organism for nitrogen excretion?
A) A B) B C) C D) D - Answer-D) D
Adrenalin (epinephrine) is the "fight-or-flight hormone". Given this, which of the following
does
NOT typically occur in response to the release of adrenalin?
A) Glycogen breakdown in the muscle.
C) Glycolysis in the muscle.
B) Gluconeogenesis in the liver.
D) Glycogen synthesis in the liver. - Answer-D) Glycogen synthesis in the liver.
Why does the catabolism of fat produce more energy than an equivalent mass of
carbohydrate?
A) Fat catabolism produces more reduced cofactors gram per gram.
B) Carbohydrate catabolism involves substrate-level phosphorylation.
C) Carbohydrate is catabolized anaerobically.
D) Fat catabolism leads to the formation of thioesters. - Answer-A) Fat catabolism
produces more reduced cofactors gram per gram.
Glutamate dehydrogenase, which calatyzes the reaction below, is allosterically
regulated by a variety of metabolites. What would be the effect of ADP and NADH on
this enzyme's activity?
A) ADP would inhibit the enzyme and NADH would activate it.
B) Both ADP and NADH would inhibit the enzyme
C) ADP would activate the enzyme and NADH would inhibit it.
D) Both ADP and NADH would activate the enzyme. - Answer-C) ADP would activate
the enzyme and NADH would inhibit it.
What is the net energetic cost of the Cori cycle per mole of glucose starting from the
muscle's
glycogen store?
A) 1 ATP, 2 GTP and 2 NADH
C) 1 ATP and 2 GTP
B) 2 ATP, 2 GTP and 2 NADH
D) 2 ATP and 2 GTP - Answer-C) 1 ATP and 2 GTP
If the fatty acid 14:1 is completely catabolized to CO2 and H2O, what would be the net
yield of ATP? (Assume that re-oxidation of NADH via the electron transport chain yields
the equivalent of
2.5 ATP, and that re-oxidation of QH2 yields 1.5 ATP.)
A) 90.5 ATP B) 89.5 ATP C) 78.5 ATP D) 92 ATP E) 94 ATP - Answer-A) 90.5 ATP
Which of the following does NOT correctly describe insulin's role in human metabolism?
A) Insulin activates glycogenolysis.
B) Insulin results in fatty acids being stored as fat in adipocytes.
REVISED ANSWERS
The commercial herbicide Roundup inhibits chorismate synthesis in plants. Chorismate
is the precursor for the biosynthesis of aromatic amino acids. Which amino acids would
likely become essential for weeds growing in crop-fields being sprayed with Roundup
("Roundup ready")?
A) Phe, Pro, Thr B) Phe, Tyr, Trp C) Tyr, Trp, Thr D) Pro, Tyr, Phe E) Pro, Tyr, Trp -
Answer-B) Phe, Tyr, Trp
What is the product of the following transaminase reaction: arginine + α-ketoglutarate --
>
glutamate +
A) A B) B C) C D) D - Answer-D) D
Under which one of the following conditions does the biosynthesis of fatty acids in the
liver mainly
occur?
A) After ingestion of excess triacylglycerols.
, D) High carbohydrate intake.
B) Low carbohydrate intake.
E) None of the above.
C) High cholesterol intake. - Answer-D) High carbohydrate intake.
Of the molecules below, which is not used by any organism for nitrogen excretion?
A) A B) B C) C D) D - Answer-D) D
Adrenalin (epinephrine) is the "fight-or-flight hormone". Given this, which of the following
does
NOT typically occur in response to the release of adrenalin?
A) Glycogen breakdown in the muscle.
C) Glycolysis in the muscle.
B) Gluconeogenesis in the liver.
D) Glycogen synthesis in the liver. - Answer-D) Glycogen synthesis in the liver.
Why does the catabolism of fat produce more energy than an equivalent mass of
carbohydrate?
A) Fat catabolism produces more reduced cofactors gram per gram.
B) Carbohydrate catabolism involves substrate-level phosphorylation.
C) Carbohydrate is catabolized anaerobically.
D) Fat catabolism leads to the formation of thioesters. - Answer-A) Fat catabolism
produces more reduced cofactors gram per gram.
Glutamate dehydrogenase, which calatyzes the reaction below, is allosterically
regulated by a variety of metabolites. What would be the effect of ADP and NADH on
this enzyme's activity?
A) ADP would inhibit the enzyme and NADH would activate it.
B) Both ADP and NADH would inhibit the enzyme
C) ADP would activate the enzyme and NADH would inhibit it.
D) Both ADP and NADH would activate the enzyme. - Answer-C) ADP would activate
the enzyme and NADH would inhibit it.
What is the net energetic cost of the Cori cycle per mole of glucose starting from the
muscle's
glycogen store?
A) 1 ATP, 2 GTP and 2 NADH
C) 1 ATP and 2 GTP
B) 2 ATP, 2 GTP and 2 NADH
D) 2 ATP and 2 GTP - Answer-C) 1 ATP and 2 GTP
If the fatty acid 14:1 is completely catabolized to CO2 and H2O, what would be the net
yield of ATP? (Assume that re-oxidation of NADH via the electron transport chain yields
the equivalent of
2.5 ATP, and that re-oxidation of QH2 yields 1.5 ATP.)
A) 90.5 ATP B) 89.5 ATP C) 78.5 ATP D) 92 ATP E) 94 ATP - Answer-A) 90.5 ATP
Which of the following does NOT correctly describe insulin's role in human metabolism?
A) Insulin activates glycogenolysis.
B) Insulin results in fatty acids being stored as fat in adipocytes.
