Pentose Phosphate Shunt + Cellular Fuels

Question 1

Pentose shunt yields:

Answer 1

NADPH for FA & cholesterol synth
Maintains glutathione as reduced GSH to act as an anti-oxidant

Ribose-5-P for nucleotide synth

Question 2

G6PDH acts as what as what in the pentose shunt?

Answer 2

First and rate limiting enzyme of pentose shunt

Question 3

Pentose phosphate shunt expressed by:

Answer 3

All cells.

Note that all but RBC synth nucleotides & have mitochondria

Question 4

Why do RBC require GSH?

Answer 4

GHS helps to prevent excessive oxidative damage to hemoglobin
-Rely exclusively on pentose shunt NAPDH to maintain reduced glutathione (GSH)

Question 5

G6PDH Deficiency

Answer 5

• Most pts asymptomatic

- Oxidative stress can cause transient hemolytic anemia in these pts

Question 6

Oxidative stressor examples

Answer 6

Infection
Certain drugs
Fava beans

Question 7

Postprandial State

Answer 7

4 hrs post meal
Glucagon:insulin is low
Insulin secretion stim, glucagon secretion inhib

Question 8

Fasting State

Answer 8

Low [Glucose] :

• stim glucagon
• inhib insulin

Low [Insulin]:
-prevents glucagon inhib

Question 9

RBC fuel source during fasting is _____

Answer 9

Glucose

Question 10

Brain fuel source during fasting

Answer 10

Glucose

KB

Question 11

Liver, Adipose fuel source during fasting

Answer 11

FA

Question 12

SKM fuel source during fasting

Answer 12

FA

KB

Question 13

G6PDH generates ___

Answer 13

1st of the 2 NADPHs

Question 14

G6PDH is stimulated by ___

Answer 14

Insulin (+) in liver and adipose