Question

The primary regulatory point of gluconeogenesis is____?

a. glucose-6-phosphatase

b. fructose-1,6-biphosphatase

c. fuctose-2,6-biphosphatase

d. pyruvate carboxylase (wrong answer)

e. PEP carboxykinase

Please explain why pyruvate carboxylase is wrong (isn't it one of the regulatory points, is it wrong because it isn't the primary one? and if so, how do you know what the primary one is?) and state the right answer and an explanation as to why.

Answer 1

The primary regulatory point of gluconeogenesis is___

b. fructose-1,6-biphosphate

It's occur mainly in liver and some extent in renal cortex. The pathway is cytoplasmic and partly mitochondrial.

*Phosphoenolpyruvate undergoes reversal of glycolysis until fructose 1,6-bisphosphate is produced.

*Enzyme fructose 1,6-bisphosphatase convert fructose 1,6-bisphosphate to fructose 6-phosphate.This enzyme is absent in smooth muscle and heart.

Please comment if any doubt.

Thanks...