Biochemistry 6th Edition by Reginald Garrett,Charles Grisham

Exercise 13

Energetics of PEP hydrolysis (Integrates with Chapter 3.) The standard free energy change (?G°') for hydrolysis of phosphoenolpyruvate (PEP) is -62.2 kJ/mol. The standard free energy change (?G°') for ATP hydrolysis is -30.5 kJ/mol.
A) What is the standard free energy change for the pyruvate kinase reaction:
ADP + phosphoenolpyruvate ? ATP + pyruvate
B) What is the equilibrium constant for this reaction?
C) Assuming the intracellular concentrations of [ATP] and [ADP] remain fixed at 8 mM and 1 mM, respectively, what will be the ratio of [pyruvate]/[phosphoenolpyruvate] when the pyruvate kinase reaction reaches equilibrium?