152 



CONTROL MECHANISMS IN CELLULAR PROCESSES 



Eys and Warnock, 1959 ) ( Fig. 5-1 ) . With measurable DPNH levels 

 restored, the removal of glycolytically reduced DPN can be a rate- 

 limiting step, which determines the rate of aerobic lactic acid pro- 

 duction. 



9. On 



5 10 



UNITS HEXOKINASE ADDED 



Fig. 5-1. The effect of the addition of hexokinase and 2-deoxyglucose on 

 aerobic glycolysis of fructose diphosphate. All flasks contained 30 //mole of 

 2-deoxyglucose. One unit of hexokinase is that amount of enzyme which phos- 

 phorylates 1 /imole of glucose per minute. 



The following experiments performed by Mr. Warnock in this 

 laboratory illustrate this. In mouse liver homogenates the lactic acid 

 production from fructose diphosphate can be lowered if microsomes 

 and cytochrome c are added ( Table 5-3 ) . This effect is seen only 



