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26 Cards in this Set

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Glycolysis is divided into the preparatory phase and the pay-off phase. How many ATP molecules are used per glucose
in the preparatory phase and how many are produced per
glucose in the payoff phase?
A. 1 and 2
B. 4 and 2
C. 3 and 6
D. 1 and 4
E. 2 and 4
F. 2 and 2
E. 2 and 4
The preparatory phase of glycolysis starts with the formation of
A. glycogen
B. glucose-6-phosphate
C. glucose-1-phosphate
D. glucose
E. glyceraldehyde-3-phosphate
F. fructose-1-phosphate
B. glucose-6-phosphate
In alphabetical order, the five enzymes of the preparatory phase of glycolysis are: 1. aldolase, 2. hexokinase, 3. phos-
phofructokinase, 4. phosphohexose isomerase and 5. triose
phosphate isomerase. In what order do they process glucose
in glycolysis?
A. 4, 3, 5, 1, 2
B. 2, 4, 3, 1, 5
C. 2, 1, 4, 5, 3
D. 1, 5, 4, 2, 3
E. 1, 2, 3, 4, 5
B. 2, 4, 3, 1, 5
The payoff phase of glycolysis starts with the conversion of
glyceraldehyde-3-phosphate, Pi and NAD+ to
A. phosphoenolpyruvate and H2O
B. 1,3-bisphosphoglycerate, NADH and H+
C. 3-phosphoglycerate
D. 2-phosphoglycerate, NADH and H+
E. 3-phosphoglycerate and ATP
B. 1,3-bisphosphoglycerate, NADH and H+
The enzyme catalyzing the first reaction of the payoff phase of glycolysis is
A. phosphoglycerate mutase
B. pyruvate kinase
C. triose phosphate isomerase
D. glyceraldehyde-3-phosphate dehydrogenase
E. phosphoglycerate kinase
D. glyceraldehyde-3-phosphate dehydrogenase
The net products of glycolysis after ten rxns starting with glucose are
A. 2 pyruvate, 2 H+, 2 ATP, 2 H2O
B. 2 lactate, 2 NADH
C. 2 pyruvate, 2 ATP, NADH
D. pyruvate, ATP
E. 2 pyruvate, 4 ATP, 2 NADH, 2 H2O
F. 2 pyruvate, 2 NADH, 2 H+, 2 ATP, 2 H2O
F. 2 pyruvate, 2 NADH, 2 H+, 2 ATP, 2 H2O
The shown glycolytic intermediate is a substrate for which enzyme
A. glucokinase
B. phosphoglucomutase
C. aldolase
D. phosphofructokinase-2
E. hexokinase
F. phosphofructokinase-1
F. phosphofructokinase-1
An intermediate Schiff base between an enzyme amino group
and a f-keto substrate group is formed during the glycolytic reaction catalyzed by
A. phosphoglycerate kinase
B. hexose isomerase
C. enolase
D. phosphofructokinase
E. phosphoglycerate mutase
F. aldolase
F. aldolase
What do the two enzymes, phosphoglycerate mutase and
phosphoglucomutase, have in common?
A. They are both enzymes of the ten core reactions of gly-
colysis.
B. They both generate NADH.
C. They both have a phosphoryl group transiently bound
in the active center.
D. They both use ATP.
E. They both have 3-carbon compounds as subtrate.
F. None of the above.
C. They both have a phosphoryl group transiently bound in the active center.
If 2-[14C]-glucose is fed to yeast and glycolytic intermediates are analyzed shortly thereafter, which carbon(s) is (are) found labeled in half of the 3-phosphoglycerate molecules.
A. C3
B. C4
C. C2
D. C1
E. All of the above.
F. None of the above.
C. C2
Pyruvate produced by glycolysis can have different fates.
Which statement is not correct?
A. It can be converted to acetyl-CoA and enter the TCA
cycle.
B. It can be converted to ethanol in yeast under aerobic
conditions.
C. It can be converted to ethanol in yeast under anaerobic
conditions.
D. Whenever an alligator moves for some time, it will con-
vert pyruvate into lactate.
E. It can be converted to alanine in one step.
F. It can be converted to lactate in the anaerobic muscle.
B. It can be converted to ethanol in yeast under aerobic
conditions.
Why is it critical for glycolysis under anaerobic conditions in the active muscle that pyruvate is converted to lactate?
Lactate production under these conditions is necessary to
A. generate ADP
B. stop bacterial growth
C. regenerate NAD+
D. produce NADH
E. avoid muscle cramps
C. regenerate NAD+
Which enzyme is not involved in converting galactose into
glucose-6-phosphate?
A. galactokinase
B. UDP-glucose epimerase
C. UDP-glucose:galactose-1-phosphate uridyltransferase
D. phosphohexose isomerase
E. phosphoglucomutase
D. phosphohexose isomerase
Gluconeogenesis bypasses three reactions of glycolysis. One
of these glycolytic reactions is catalyzed by
A. glyceraldehyde-3-phosphate dehydrogenase
B. phophoglycerate mutase
C. enolase
D. pyruvate kinase
E. phosphoglycerate kinase
D. pyruvate kinase
Which statement is not true about oxaloacetate formation
during gluconeogenesis when pyruvate serves as a substrate?
A. It is produced in the cytosol.
B. It is produced in the mitochondrion.
C. It is produced by the action of pyruvate dehydrogenase.
D. It is produced by the action of cytosolic malate dehydrogenase.
E. It is produced by the action of mitochodrial pyruvate carboxylase.
C. It is produced by the action of pyruvate dehydrogenase.
Which of the following compounds are intermediates of
the oxidative pentose phosphate pathway: 1. fructose-6-
phosphate; 2. ribulose-5-phosphate; 3., sedoheptulose-7-
phosphate; 4. ribose-5-phosphate; 5. erythrose-4-phosphate;
and 6. xylulose-5-phosphate.
A. 2, 3, 4, 5, 6
B. 1, 2, 3, 5, 6
C. 1, 3, 4, 6
D. 1, 2, 3, 4, 5, 6
D. 1, 2, 3, 4, 5, 6
Which of the following compounds are phosphorylated pentoses: 1. fructose-6-phosphate; 2. ribulose-5-phosphate;
3., sedoheptulose-7-phosphate; 4. ribose-5-phosphate; 5.
erythrose-4-phosphate; and 6. xylulose-5-phosphate?
A. 1, 2, 3
B. 2, 3, 4
C. 3, 4, 5
D. 4, 5, 6
E. 2, 4, 6
F. 1, 3, 5
E. 2, 4, 6
Which statement is incorrect? A genetic defect in glucose-6-
phosphate dehydrogenase in red blood cells of humans
A. affects a relatively large number of people.
B. increases the susceptibility to the toxic effects of anti-
malarial drugs.
C. is detrimental under conditions that produce reactive
oxygen species.
D. provides a genetic advantage in malaria-infested coun-
tries.
E. is the cause of adult lactose intolerance in large population groups.
F. causes fava beans to be toxic.
E. is the cause of adult lactose intolerance in large population groups.
You want to distinguish whether a particular tissue metabolizes glucose primarily by the oxidative pentose phosphate pathway or by glycolysis. You correctly hypothesized that
measuring the rate of carbon dioxide release might provide
the answer. You have a choice of 6 synthetic glucose molecules
available to you, each labeled at a different carbon. Which of
the 6 compounds is best suited for this experiment?
A. C2
B. C6
C. C1
D. C5
E. C3
F. C4
C. C1
Thiamine pyrophosphate is an important cofactor of which
enzyme of the oxidative pentose phosphate pathway?
A. transketolase
B. ribose-5-phosphate isomerase
C. transaldolase
D. 6-phosphogluconate dehydrogenase
E. glucose-6-phosphate dehydrogenase
F. phosphopentose isomerase
A. transketolase
In gluconeogenesis, how many nucleoside triphosphates does
it take to convert 2 pyruvates into one glucose?
A. 7
B. 2
C. 3
D. 4
E. 6
F. 5
E. 6
Which statement is not true? The glycolytic enzyme PFK-1
and the gluconeogenic enzyme FBPase-1 are not engaged in
a futile cycle because
A. AMP stimulates PFK-1
B. AMP inhibits FBPase-1
C. ATP inhibits PFK-1
D. ATP inhibits FBPase-1
E. fructose-2,6-bisphosphate increases the affinity of PFK-
1 for its substrate
F. fructose-2,6-bisphosphate decreases the affinity of
FBPase-1 for its substrate
D. ATP inhibits FBPase-1
Hexokinase IV catalyzes the first reaction of glycolysis in the liver. Three properties distinguish it from the hexokinase iso-
form in muscle. Identify those three properties in this list: 1. Hexokinase IV is reversibly phosphorylated; 2. Hexokinase IV is not feedback-inhibited by its product; 3. Hexokinase
IV can be sequestered into the nucleus; 4. Hexokinase IV’s activity is responsive to glucose over a wide range of concentrations; and 5. Hexokinase IV is stimulated by ATP.
A. 3, 4, 5
B. 1, 3, 4
C. 1, 4, 5
D. 2, 3, 4
E. 1, 2, 3
D. 2, 3, 4
Which statement is not correct about glycogen?
A. Glycogen has many reducing ends.
B. Glycogenin is covalently bound at the core of the
molecule.
C. Glucose residues are _1!4 linked.
D. Glucose residues are _1!6 linked.
E. One molecule contains about 50,000 glucose residues.
A. Glycogen has many reducing ends.
Which enzyme is not required for biosynthesis of glycogen
from glucose-6-phosphate in liver?
A. UDP-glucose pyrophosphorylase
B. glycogenin
C. phosphoglucomutase
D. glycogen synthase
E. glycogen branching enzyme
F. hexokinase
F. hexokinase
Which statement about glycogen degradation is not true?
A. Glycogen phosphorylase generates glucose-1-phosphate.
B. Glycogen phosphorylase stops four residues from a
glycogen branch point.
C. The debranching enzyme transfers three glucose
residues from a branch to a non-reducing end.
D. Water is involved in the phosphorylysis of glycogen.
E. The debranching enzyme cleaves _1,6 linkages.
D. Water is involved in the phosphorylysis of glycogen.