270 F. Lynen, et al. 



rate of fermentation. Thus, if the Pasteur effect is eUminated 

 by cyanide or an uncouphng agent, the induced fermentation 

 leads after a short transitional period to the increase in fruc- 

 tose diphosphate which was observed experimentally (Figs. 8, 

 10). Simultaneously ATP, the polyphosphates and glucose- 

 6-phosphate increase, due to the gradual substitution of 



Fig. 10. Changes in the inorganic and organic phosphates of baker's 



yeast, following the addition of 2 : 4-dinitrophenol. 

 Yeast, 10 per cent ; glucose, 2 per cent ; in • 02 m citrate buffer, pH 5 • 4 ; 

 temp. 15° ; oxygenated; 4 x 10^* m dinitrophenol added at arrow. The 

 ordinate values refer to changes in concentration of compounds specified. 



energy supply by fermentation. The inorganic phosphate 

 decreases again and is maintained at a higher level than before 

 cyanide addition, as is required by the theory. 



The changes observed on switching from fermentation to 

 respiration also fit this picture. It is remarkable that ATP 

 and ADP are not affected by aeration, as shown experiment- 

 ally (Fig. 11). This is difficult to reconcile with the theory, 



