Question

If 1,6 Fructose biphosphate (FBPASE-1) had a 50% lower affinity for citrate, which of the following changes would occur in the fasted state?

A. AMP would increase

B. Glucagon would increase

C. 2,6 fructose biphosphate would increase

D. Insulin would increase

Answer 1

1. Answer: Option B is correct
Explanation:
Fructose 1, 6-bisphosphatase is an important enzyme involved in Gluconeogenesis.
It is allosterically activated by Citrate.
It is allosterically inhibited by AMP and Fructose 2, 6-bisphosphate.

If Fructose 1, 6-bisphosphatase exhibits only 50% affinity for citrate, its activation will be reduced.
As a result, the rate of gluconeogenesis will be reduced.
i.e. the amount of glucose produced will be decreased.
This stimulates glucagon secretion to promote glycogenolysis and gluconeogenesis.