Effects of 2,4-Dinitrophenol Concentrations on Rates of Respiration and Fermentation of Yeast. ∗

Abstract

Summary

Low concentrations of DNP stimulate the respiration of living yeast cells in the presence or absence of glucose. Respiration in the absence of substrate is normally insensitive to CO, but the increment increase due to DNP is sensitive to CO. Higher concentrations of DNP inhibit both respiration and fermentation of glucose. However, the respiratory pathway is considerably more sensitive to the inhibitor than is the fermentation pathway. In consequence, at certain concentrations of DNP, the Pasteur effect is depressed and there is a striking increase in the rate of aerobic fermentation.