BCH 361 CHAPTER 18 TEST
QUESTIONS WITH ALL CORRECT
ANSWERS
Beriberi involves a reduction in the activity of pyruvate dehydrogenase complex. Which
enzyme(s) in the complex is/are specifically affected in this disease through loss or
reduction of a prosthetic group? - pyruvate dehydrogenase component (E1)
When pyruvate initially binds to the pyruvate dehydrogenase complex, which of the
following statements is TRUE? - The cofactor of E3 is in its reduced form
Which of the following is NOT a coenzyme necessary in the function of pyruvate
dehydrogenase complex?
a. thiamine pyrophosphate (TPP)
b. FAD
c. lipoic acid
d. NAD+
e. ubiquinone - e. ubiquinone
Entry to the citric acid cycle involves the generation of acetyl CoA. The enzyme that
catalyzes the production of acetyl CoA is . This enzyme is negatively regulated by
in a high-energy charge situation. - pyruvate dehydrogenase; NADH
Pyruvate dehydrogenase complex falls within which size range? - 4—10 million daltons
The formation of acetyl CoA from pyruvate is an irreversible step in animals, and thus
they are unable to convert into . - acetyl CoA; glucose
Which of the following lists the steps in the conversion of pyruvate into acetyl CoA by
pyruvate dehydrogenase complex in the CORRECT order? - decarboxylation; oxidation;
transfer reaction
Beriberi patients have higher blood levels of which compound(s)? - pyruvate
If pyruvate is labeled with 14C at the central carbon, which of the following molecules
will NOT contain 14C during/after the conversion of the pyruvate to acetyl CoA
catalyzed by pyruvate dehydrogenase complex? - CO2
The mechanism of inhibition of dihydrolipoyl dehydrogenase by arsenite involves: - both
the release of two water molecules and an oxidation reaction
Negative regulation of citric acid cycle enzymes in a muscle cell would lead to
and - a reduction in the rate of glycolysis; lower ATP production
Assume that in a cell the ratio listed is high. Which ratio(s) would lead to a decrease in
the rate of entrance of acetyl CoA into the citric acid cycle? - NADH/NAD+
QUESTIONS WITH ALL CORRECT
ANSWERS
Beriberi involves a reduction in the activity of pyruvate dehydrogenase complex. Which
enzyme(s) in the complex is/are specifically affected in this disease through loss or
reduction of a prosthetic group? - pyruvate dehydrogenase component (E1)
When pyruvate initially binds to the pyruvate dehydrogenase complex, which of the
following statements is TRUE? - The cofactor of E3 is in its reduced form
Which of the following is NOT a coenzyme necessary in the function of pyruvate
dehydrogenase complex?
a. thiamine pyrophosphate (TPP)
b. FAD
c. lipoic acid
d. NAD+
e. ubiquinone - e. ubiquinone
Entry to the citric acid cycle involves the generation of acetyl CoA. The enzyme that
catalyzes the production of acetyl CoA is . This enzyme is negatively regulated by
in a high-energy charge situation. - pyruvate dehydrogenase; NADH
Pyruvate dehydrogenase complex falls within which size range? - 4—10 million daltons
The formation of acetyl CoA from pyruvate is an irreversible step in animals, and thus
they are unable to convert into . - acetyl CoA; glucose
Which of the following lists the steps in the conversion of pyruvate into acetyl CoA by
pyruvate dehydrogenase complex in the CORRECT order? - decarboxylation; oxidation;
transfer reaction
Beriberi patients have higher blood levels of which compound(s)? - pyruvate
If pyruvate is labeled with 14C at the central carbon, which of the following molecules
will NOT contain 14C during/after the conversion of the pyruvate to acetyl CoA
catalyzed by pyruvate dehydrogenase complex? - CO2
The mechanism of inhibition of dihydrolipoyl dehydrogenase by arsenite involves: - both
the release of two water molecules and an oxidation reaction
Negative regulation of citric acid cycle enzymes in a muscle cell would lead to
and - a reduction in the rate of glycolysis; lower ATP production
Assume that in a cell the ratio listed is high. Which ratio(s) would lead to a decrease in
the rate of entrance of acetyl CoA into the citric acid cycle? - NADH/NAD+
