Gluconeogenesis

Question 0

Where does Gluconeogenesis occur?

Answer 0

1. Liver (90%)

2. Kidneys (10%), prolonged fasting (40%)

Question 1

Gluconeogenesis prevents?

Answer 1

Hypoglycemia

intermediates:

1. intermediates of glycolysis and tca(krebs)
2. glycerol
3. lactate (cori cyce)
4. glucogenic aminoacids

Question 2

A. Substrate for gluconeogenesis?

B. Product of gluconeogenesis?

Answer 2

a. Pyruvate

b. Glucose

Question 3

A. Rate limiting step in gluconeogenesis?

B. Rate limiting enzyme?

Answer 3

a. conversion of fructose 1,6-bisphosphate > fructose 6-phosphate
b. fructose 1,6 bisphosphatase

Question 4

Co factor of pyruvate carboxylase?

Answer 4

Biotin

*if the enzyme ends with carboxylase the co factor is always biotion

Question 5

At what level of venous blood glucose concentration does glucosuria occur?

Answer 5

> 9.5-10.0 mmol/L renal threshold for venous blood glucose concentration

Question 6

What does high amounts of NADH favors? what will be its effect on gluconeogenesis?

Answer 6

High NADH favors:

1. pyruvate > lactate
2. OAA > malate
3. DHAP > glycerol 3 phosphate

*NADH diverts pyruvate to lactate and OAA to malate which would decrease gluconeogenesis

Question 7

What would cause Increase NADH?

Answer 7

ethanol metabolism generates NADH

*Aldehyde causes flushing during alcohol intake