Enzymes and their applications / By Dr. Jean Effront ... English translation by Samuel C. Prescott ... v. 1. The enzymes of the carbohydrates. The oxidases.

  • Effront, Jean, 1850-1931.
Date:
1902
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Licence: Public Domain Mark

Credit: Enzymes and their applications / By Dr. Jean Effront ... English translation by Samuel C. Prescott ... v. 1. The enzymes of the carbohydrates. The oxidases. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    are favored in living cells by physical and chemical conditions peculiar to the medium. This proposition cannot be con- sidered as an explanation of intercellular phenomena. We cannot really understand them except by a thorough study of the media in which they are produced. A careful study of these conditions shows that the ready occurrence of all inter- cellular reactions is not to be ascribed to a single cause; that the affinity is sometimes favored by a purely physical con- dition and sometimes by a purely chemical one. Certainly, we are far from knowing all the conditions which favor inter- cellular reactions, but it has been possible to study some among them, and from the acquired knowledge, one may conclude that whenever one observes an increase of cellular energy, this is produced, not by a single condition common to all such phenomena, but by a cause strictly determinable and differing in different cases. We know certain reactions in which chemical affinity in- creases because of purely physical conditions, such as osmosis, which continually occurs through cell membranes. In other cases we find that reactions are favored in the cells by the presence of mineral substances. The decomposition of sodium chloride, for example, and the formation of hydrochloric acid in certain cells is one of those phenomena which do not accord at all with the general ideas we have of the stability of certain substances. We know, in fact, that sodium chloride is a very stable substance, and that its decomposition in the cold, in a medium slightly acidified by weak acids, is impossible. Thus the de- composition of sodium chloride in the cells was formerly* explained by the intervention of vital energy, which was said to render the body less stable and more readily decomposed. To-day a more rational explanation is given to the phenom- enon: we recognize that the decomposition of sodium chloride is caused simply by osmosis and independently of vital energy, because the salt, in a very dilute solution, is dissociated. In the cells an analogous phenomenon of dis-