452 CHEMICAL DYNAMICS 



not entering to any appreciable extent into the reaction, and there- 

 fore not requiring the expenditure of any energy to withdraw it 

 from the system. Most investigators will prefer to assume, from 

 Dietz' results, that lipase is not a "typical" catalysor, but enters 

 appreciably into the reaction which it catalyses (10) (11). 



7. Biological Applications. — It may here be noted that the 

 hypothesis outlined above is not inconsistent with the generally 

 expressed view that the enzyme may be recovered without appreci- 

 able loss of activity from a protein digest which has reached equi- 

 librium. Even if, in consequence of the presence of protein, the 

 station of equilibrium between the two modifications of the 

 enzyme has been shifted in such a direction as to diminish its 

 power of accelerating hydrolysis, yet upon removal from the 

 system the enzyme would regain its normal equilibrium, although, 

 of course, this process might involve a greater or a shorter period 

 of time. The energy thus apparently gained would be slowly lost 

 through the slow (because of the absence of catalysors) regaining 

 of equilibrium between the protein and its products. The protein 

 ^ products system would, in other words, be left "supersaturated " 

 in respect to products, or, were the enzyme in the system highly 

 concentrated, or did it, for any other reason, initially contain a 

 high proportion of anhydrous (synthesis-accelerating) form so that 

 it gained power of accelerating hydrolyses as a result of the presence 

 of protein, then the protein <=^ products system would be left, by 

 removal of the enzyme, "supersaturated" with respect to protein. 

 In the former case the anhydrous ^ hydrated enzyme system 

 would be left supersaturated with respect to the anhydrous 

 (synthesis-accelerating) form, in the latter, with respect to the 

 hydrated (hydrolysis-accelerating) form. By mechanical separa- 

 tion of the enzyme and substrate at various periods in living 

 tissues it is obvious that a cycle of such operations could occur, 

 the enzyme being utilized over and over again, now for hydrolysis 

 and now for synthesis. It is obvious that if such reciprocal rela- 

 tions as that outUned above find a place in living material, the 

 organism may be enabled thereby to temporarily and locally store 

 up large quantities of energy. The significance of this possibihty 

 in the general interpretation of life-phenomena is patent. 



Finally, it may be pointed out that the conceptions which I have 

 developed above enable us to understand how the living organism, 

 through temporary mechanical or chemical separation and localiza- 



