186 



COLLOIDS IN BIOLOGY AND MEDICINE 



We learn from this table that analysis by simple adsorption may 

 replace the more difficult and complicated electric migration. It is 

 very instructive for our knowledge of enzymes, that their action is 

 strongest with the reaction which expresses their own charges as may 

 be seen from the following table (from L. MICHAELIS) : 



Optimum Activity Occurs 

 with an H-ion Concentration of 



Water 1 . 10~ 7 



Invertase 2. 10~ 5 



Maltase 2.5.1Q- 7 



Trypsin 2. 10-* 



Erepsin 2. 1Q- 8 



Pancreatic lipase 2 . 10" 8 



Pepsin 2 . 10~ 2 



