Energetics of fructose-1,6-bisP hydrolysis (Integrates with Chapter 3.) The standard free energy change (ΔG°’) for hydrolysis of fructose-l, 6- bisphosphate (FBP) to fructose-6-phosphate (F-6-P) and Pi is -16.7 kJ/mol:
FBP + H2O → fructose-6-P + Pi
The standard free energy change (ΔG°’) for ATP hydrolysis is -30.5 kJ/mol:
ATP + H,→ ADP + Pi
a. What is the standard free energy change for the phosphofructokinase reaction:
ATP + fructose-6-phosphate ADP + FBP
b. What is the equilibrium constant for this reaction?
c. Assuming the intracellular concentrations of [ATP] and [ADP] are maintained constant at 4 mM and 1.6 mM, respectively, in a rat liver cell, what will be the ratio of [FBP]/[fructose-6-P] when the phosphofructokinase reaction reaches equilibrium?