JOHN H. NORTHROP 



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present the greater the percentage of combined and therefore stable 

 trypsin. In a solution, therefore, originally containing trypsin and 

 inhibiting (protective) substances, the percentage of the trypsin that 



12 3 4 



Hours at 38*^ 



Fig. 1. Inactivation of various trypsin solutions at 38°C. 



is free is constantly decreasing. Since it is this quantity that deter- 

 mines the rate of inactivation, the rate of inactivation will also con- 

 stantly decrease and the resulting decomposition curve will fall more 



