Biochemistry 4th Edition by Reginald Garrett, Charles Grisham

Exercise 11

Energetics of the triose phosphate isomerase reaction
(Integrates with Chapter 3.) Triose phosphate isomerase catalyzes the conversion of dihydroxyacetone-P to glyceraldehyde-3-P. The standard free energy change, Gº', for this reaction is +7.6 kJ/mol. However, the observed free energy change ( G) for this reaction in erythrocytes is + 2.4 kJ/mol.
a. Calculate the ratio of [dihydroxyacetone-P]/[glyceraldehyde-3-P] in erythrocytes from G.
b. If [dihydroxyacetone-P] = 0.2 mM, what is [glyceraldehyde-3-P]