ENZYMES Si 



A PHYSIOLOGICAL PROBLEM: ENZYMES 



BY ORVILLE HARRY BROWN, Ph.D., M.D. 

 PHYSICtAN IN CHIEF OF THE MISSOURI STATE SANATORIUM FOR INCIPIENT TUBERCULOSIS 



MT. VERNON, MO. 



THE question of enzymes is one of fascinating interest to the 

 biologist. There is more or less of a mystical atmosphere sur- 

 rounding these unknown ever-present bodies in all living organisms, 

 on account of the difficulty in effecting their isolation, and in regard 

 to the method in which they perform their function. The study of 

 enzymes has been pursued with much vigor for years by eminent in- 

 vestigators of the biological sciences, and yet their exact nature is 

 almost as little understood to-day as ever. Xo enzyme has been abso- 

 lutely isolated, and consequently the chemical constitution of these 

 principles is yet a matter of conjecture. We can, however, unerringly 

 detect their presence, both qualitatively and quantitatively. 



The terms enzyme and ferment as used to-day are practically 

 synonymous. The latter term is doubtless the more familiar of the 

 two to the laity. A classical example of fermentation is the changing 

 of sugar, by means of yeast, to alcohol and carbonic acid gas. The 

 yeast is necessary to this process, in so far as it elaborates the active 

 agent — enzyme, or ferment — which is essential. The yeast, more 

 properly according to our former conception, than now, is spoken of as 

 an organized ferment. This was on account of the supposition that the 

 yeast itself was the ferment. It has only recently been shown that 

 a substance can be extracted from the yeast cell, which brings about 

 the process, spoken of as fermentation. In contradistinction to the 

 organized ferments there were the unorganized ferments, as, for 

 example, the enzymes of the alimentary canal, which were capable of 

 bringing about digestion as w T ell outside of the body in a test beaker, 

 as in their normal habitat, the stomach and intestines. The separa- 

 tion of a material from the yeast cell, which still possessed its activity 

 made obsolete the classification of unorganized and organized ferments. 

 The agents which were formerly classified under the two heads, 

 although differing in characteristics, are alike in that both are definite 

 chemical substances secreted or manufactured by cells — a single-celled 

 organism in one case and a multicellular in the other. Many bacteria 

 were formerly believed to belong to the same class as the yeast, and 

 thought to possess a fermentative function; now it is known that the 

 bacteria elaborate a substance which has the enzymotic properties. 



The physiologist defines an enzyme as a body, which, remaining 



