ANALYSIS OF DRUG ACTION 



79 



of the drug on a given enzyme system is the same as it 

 would be on the same enzyme in aqueous solution. 

 The analysis is further complicated by the fact that the 



100 



200 



100 



Concentration x 10 



Fig. 1 3. The eflfect of dichlorophenol upon the respiration (a) and cleavage 



(b) of Arbacia ova. Note that there is little effect on cleavage until the 



increase in respiration is almost complete. 



effect of an enzyme poison may affect different cellular 

 processes in different ways. As is shown by Fig. 12 

 phenol increases the rate of fermentation of sugar by 

 yeasts, but decreases the rate of respiration. Fig 13 shows 



0.8 1.2 



"/o phenol in solution 



Fig. 14. The relationship between the uptake of phenol by yeast (a), and 

 the lethal action of phenol on yeast (b) 



