CATALYSIS AND THE ENZYMES 



living cells show different enzyme effects, we 

 find a certain variety in their combinations, 

 and never find two or more enzyme effects in- 

 separably connected in any case. So in germinating 

 seeds we very often observe catalytic effects 

 both on cane sugar and on malt sugar. In other 

 cases these two effects are strictly limited to two 

 different cell-species. In yeast Saccharomyces 

 cerevisia acts very effectively on cane sugar, but 

 not on malt sugar, whilst Saccharomyces Marxi- 

 anus only acts on malt sugar. When we prepare 

 a watery extract from both species of yeast we 

 can easily convince ourselves that even there only 

 one of the two enzyme effects is exerted. By 

 Marxianus only the splitting of maltose, by 

 Cerevisice of saccharose. We cannot doubt that 

 these two enzymes are different substances. 

 Many more difficulties arise when the enzymes 

 cannot be separated from the cells and the enzyme 

 effects are watched only in the paste of ground- 

 down cells. There it is often impossible to say 

 to what number of enzymes all these effects should 

 be attributed. All in all one feels at present in- 

 clined to indulge in the opinion that each single 

 effect corresponds to one certain enzyme. We are 

 justified in doing so, since many enzyme prepara- 

 tions have in the course of time proved to be 

 mixtures of different enzymes. It was well known 

 that preparations of starch-attacking enzymes gave 

 in most cases a blue reaction with guaiacum resin, 

 in 



