Muscle cells need energy to contract. one biochemical pathway for energy transfer is the breakdown of glucose to pyruvate in aprocess called glycolysis. In the presence of sufficient oxygen inthe cell, pyruvate is oxidized to CO2 and H2O to make furtherenergy available. However, under extreme conditions not enoughoxygen can be supplied to the cells. so muscle cells producelactate ion according to the reactionpyruvate + NADH + H+--> lactate + NAD+where delta rG*=-25.1kj/mol. in living cells, the pH value isabout 7. The hydronium ion concentration is constant and isincluded in delta G, which is then called delta r G*'.

a) Calculate delta rG* for the reaction at 25*C.

b) Calculate the equilibrium constant K'. ( the hydronium ionconcentration is included in the constant. That is K'= K. [H3O+]for the reaction at 25* C and pH= 7.0)

c) Delta r G' is the free energy change under standardconditions; that is, the concentrations of all reactants (exceptH30+) are 1.00 mol/L. Calculate delta r G' at 25*C, assuming the following concentrations in the cell: pyruvate, 380 umol/L; HAD, 50umol/L; lactae ion, 3700 umol/L and NAD+ ion, 540 umol/L