The enzyme hexokinase catalyzes the first reaction in the glycolytic pathway. In this reaction, glucose is phosphorylated to form glucose-6-phosphate (G6P) with ATP as the phosphate donor and energy source:
glucose + ATP –> glucose-6-phosphate + ADP
delta-G-naught-prime for this reaction at 25 degrees C is -4.0 kcal/mol. The concentration of ATP, ADP, and glucose-6-phosphate in a typical bacterial cell are as follows:
[ATP] = 2.0 mM [ADP] = 0.15 mM [G6P] = 0.05 mM
a) What is Keq for the reaction above at 25 degrees C? Show calculations
b) In a bacterial cell with ATP, ADP, and G6P present at the above concentrations, at what concentration of glucose would this reaction be in equilibrium?
c) Assuming that the prevailing concentration of glucose in the bacterial cell is 5.0 mM, what is the delta-G-naugh-prime for this reaction at 25 degrees C?