If the enzyme phosphohexose isomerase is added to a 0.3 M solution of fructose 6- phosphate, and the reaction is allowed to proceed to equilibrium, the ?nal concentrations tions are 0.2 M glucose 6-phosphate and 0.1 M fructose 6-phosphate. These data give an equilibrium constant of 2. What is the equi- equilibrium constant if the initial concentration of fructose 6-phosphate is 3 M?