Lecture 10 - Pentose Phosphate Shunt Flashcards Preview

Fuel Metabolism - 2016 > Lecture 10 - Pentose Phosphate Shunt > Flashcards

Flashcards in Lecture 10 - Pentose Phosphate Shunt Deck (22):
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

How is the pentose phosphate pathway linked to the activity of phagocytic cells?

Phagocytic cells generate superoxide anions and other reactive oxygen species to kill ingested bacteria.