Question

g Fructose 2,6-bisphosphate is a _______________ regulator of glycolysis and a _________________regulator of gluconeogenesis.

Answer 1

Answer:

Fructose 2,6-bisphosphate is a positive regulator of glycolysis and a negative regulator of gluconeogenesis.

Explanation:

Fructose-2,6-bisphophate is an allosteric effector of the enzymes phosphofructokinase-1, PFK-1 and fructose-1,6-bisphosphatase, FBPase-1.

When fructose-2,6-bisphosphate binds to its allosteric site on PFK-1, it increases the enzymes affinity for its substrate fructose-6- phosphate and reduces its affinity for ATP and citrate, its allosteric inhibitors. This favors favors glycolysis.

However, binding of fructose-2,6-bisphosphate on its allosteric site on FBpase-1 has the opposite effect on it. It reduces its affinity for its substrate, fructose-1,6-bisphosphate, thereby inibiting gluconeogenesis.