The following reactions can be coupled to give alanine andoxaloacetate: glutamate + pyruvate ↔ ketoglutarate + alanine ∆Go’rxn,303 = − 1004 J/mol glutamate + oxaloacetate ↔ ketoglutarate +aspartate ∆Go ’rxn,303 = − 4812 J/mol
(a) Write the form of the equilibrium constant for pyruvate +aspartate ↔ alanine + oxaloacetate and calculate the numericalvalue of the equilibrium constant at 30o C.
(b) In the cytoplasm of a certain cell, the components are atthe following concentrations: pyruvate = 10-2 M, aspartate = 10-2M, alanine = 10-4 M, and oxaloacetate = 10-5 M. Calculate the Gibbsfree energy change for the reaction of part (a) under theseconditions. What conclusion can you reach about the direction ofthis reaction under cytoplasmic conditions?
