Flashcards in Lecture 10 - Pentose Phosphate Shunt Deck (22)
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1
One function of the Pentose Phosphate pathway is recycling of excess pentose phosphates back to _________ and glycolysis. This is especially important in RBCs where there are no biosynthetic reactions.
glyceraldehyde-3-phosphate
2
What is the function of the oxidative phase of the pentose phosphate pathway?
generate NADPH and pentoses
3
What is the function of the non-oxidative phase of the pentose phosphate pathway?
recycle excess pentose phosphates
4
Which phase of the pentose phosphate pathway is irreversible?
oxidative phase
5
Which phase of the pentose phosphate pathway is reversible?
non-oxidative phase
6
The major site of regulation of the pentose phosphate pathway is __________.
glucose-6-P dehydrogenase
7
Glucose-6-P dehydrogenase, a major site of regulation in the pentose phosphate pathway, is inhibited by what two molecules?
1. NADPH
2. fatty acyl-CoA
Note: Inhibition is reversed by oxidized glutathione
8
What condition can occur in individuals deficient in glu-6-P dehydrogenase who are taking antimalarial drugs?
anemia
9
_________ reduces the iron of metHb back to its normal ferrous state and restores hemoglobin's function as an oxygen carrier.
MetHb Reductase
10
Glutathione Reductase uses _____ to reduce oxidized glutathione back to the reduced form.
NADPH
11
The pentose phosphate pathway is a major source of _____ for biosynthesis.
NADPH
12
The pentose phosphate pathway is a major source of __________ for nucleotide synthesis.
ribose-5-P
13
__________ is the only enzyme in the non-oxidative branch of the pentose phosphate pathway with a coenzyme requirement.
Transketolase - requires thiamine pyrophosphate
14
Transketolase requires a coenzyme that can be used to diagnose Wernick-Korsakoff syndrome. What coenzyme is being referred to?
Thiamine pyrophosphate - deficiency of thiamine in lysed RBCs can be used to detect a thiamine deficiency
15
How do antimalarial drugs increase oxidative stress?
Increased production of toxic oxygen metabolites
16
__________ converts hydrogen peroxide to water and molecular oxygen.
A. MetHb reductase
B. Superoxide dismutase
C. Glutathione peroxidase
D. Glutathione reductase
E. Catalase
E
17
____________ converts superoxide to hydrogen peroxide and oxygen.
A. MetHb reductase
B. Superoxide dismutase
C. Glutathione peroxidase
D. Glutathione reductase
E. Catalase
B
18
_____________ uses NADPH to return glutathione to reduced and functional form.
A. MetHb reductase
B. Superoxide dismutase
C. Glutathione peroxidase
D. Glutathione reductase
E. Catalase
D
19
__________ reduces hydrogen peroxide to water and is the most important enzyme in RB for disposal of peroxide. (Hint: it uses glutathione as a reducing agent.)
A. MetHb reductase
B. Superoxide dismutase
C. Glutathione peroxidase
D. Glutathione reductase
E. Catalase
C
20
___________ catalyzes the conversion of NADPH and oxygen to the superoxide anion.
NADPH oxidase
21
Chronic granulocytic disease is a heritable disease caused by a deficiency in what enzyme?
NADPH oxidase
22
