The temperature coefficients and energy exchanges of the citric acid dehydrogenase of cucumber seeds

Abstract

The Michaelis constant of the citric acid dehydrogenase of cucumber seed was 1.65 X 10-4 [image] at 25[degree] and 8X 10-5 [image] at 35[degree]. The heat of formation of the enzyme-substrate compound was 13,460 cal. per gm. mol. as calculated from the temp. coefficient Q10[degree]=0.48 at 30[degree]. The temp. coeff. of the velocity of the reaction catalyzed by the dehydrogenase was: Q10[degree]=1.65 at 30[degree]. From this the calculated energy of activation was 8.790 cal. per gm. mol.