The oxidation of galactose in the presence of 2,4-dinitrophenol as a measure of galactose adaptation in Saccharomyces cerevisiae

Abstract

The degree of oxidation of galactose in the presence of 2,4-dinitrophenol was used as a measure of galactose adaptation in Saccharomyces cerevisiae. The results indicated that the rate of synthesis of the limiting adaptive enzyme in the galactozymase system assumes a linear or hyperbolic form. An important implication of this finding is that it permits an explanation to be made of the kinetics of galactokinase synthesis in yeast without assuming the existence of extrachromosomal hereditary factors. A comparison of the Q O 2 and Q CO 2 N 2 at the same stages of galactose adaptation demonstrated further that the oxidative phase is not a pre-adaptive oxidation of galactose, but is also dependent upon the formation of the adaptive enzyme.