Question

Explain how fructose 2,6-bisphosphate levels are regulated in a cell, and the relationship between fructose 2,6-bisphosphate levels and blood glucose levels.

Answer 1

1.Explain how fructose 2,6-bisphosphate levels are regulated in a cell

Answer: The hormones responsible for regulation of Fructose 2,6-biphophate are insulin, glucagon, and epinephrine . These hormones regulate the reactions called as phosphorlyation/dephosphorylation.

hormone glucagon Released ---> production of cyclic adenosine monophosphate (cAMP) ---> activation of cAMP-dependent protein kinase

This kinase phosphorylates the PFK-2/FBPase-2 enzyme with ATP to activate the FBPase-2 activity

Inhibit the PFK-2 activity of the enzyme,---> thus reducing levels offructose 2,6-bisphosphate in the cell.

2. Relationship between fructose 2,6-bisphosphate levels and blood glucose levels.

In glycolysis, fructose 2,6-bisphosphate strongly activates glucose breakdown through allosteric modulation of phosphofructokinase 1 enzyme. The enzyme gets activated in presence of fructose 2,6-bisphosphate.