150 Prof. B. Moore. On the Synthesis of [June 15 r 



S-wmmary of Results and Conclusions. 



1. Analyses of the lymph contained in the mesenteric lymphatic 

 vessels during fat absorption demonstrate that at this stage of absorp- 

 tion practically all of the fatty constituents formed in the intestine 

 during digestion have been re-synthesized into neutral fat. 



This points to synthetic processes occuring in the cells present in the 

 intestinal wall, and to the further conclusion that the cells of the 

 mesenteric lymphatic glands are not normally concerned in the process 

 of synthesis of the absorbed fatty constituents. 



2. Analyses of the fatty constituents of the intestinal mucosa during 

 fat absorption show a preponderance of neutral fat, but at the same 

 time a considerable percentage of free fatty acid, showing that the 

 synthesis is in progress, and has not obtained that completion found in 

 the mesenteric lymphatic vessels. 



3. No synthesis of neutral fat has been obtained from the normal 

 cleavage constituents of fat (viz. soap and glycerine), by the action in 

 vitro either of cells of the pancreas, intestinal mucosa or lymphatic 

 glands, or of cell-free extracts of those tissues. 



This observation taken in conjunction with the results above- 

 mentioned proves that the living cell in situ, supplied with energy by 

 the circulating blood, is capable of inducing a synthesis, which is not 

 brought about by the detached cell or substances extracted from it. 



A large number of similar synthetic actions of gland cells have been 

 observed throughout the body, and this points to an important function 

 of the cell as an energy transformer in such reactions as are endothermic 

 in character, and require a supply of external energy. The action of a, 

 chemical catalyzer or enzyme is simpler in character The same 

 enzyme cannot in any known case induce two different types of 

 chemical transformation, one running exo-thermically and the other 

 endo-thermically, and in so doing use up the energy re-acquired from 

 the exo-thermic reaction. This is the essential difference between the 

 chemical activity of the living cell when supplied by energy, and that 

 of the enzyme, which in each specific instance is confined to a reaction 

 of a single type. 



An example is given by the transformation of carbohydrate into fat > 

 here part of the carbohydrate is oxidised by the cell, and the energy 

 obtained in this process is utilised for the conversion of another portion 

 of the carbohydrate into fat with the taking up of energy. In most 

 cases the reactions brought about, or increased in velocity, by enzymes 

 are exo thermic in character, giving rise to substances with less chemical 

 energy than those from which they are formed, and in the few recorded 

 cases of syntheses by enzymes, the products formed in the syntheses 

 possess no measurably greater amount of energy than those from which 

 they are formed. 



