[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
February 17, 1906


JAMA. 1906;XLVI(7):512-513. doi:10.1001/jama.1906.02510340038005

Since up to the present time no ferments have been isolated in an absolutely pure condition we are entirely unfamiliar with their chemical characters, and consequently are obliged to recognize them solely by their action. So far as we know, true enzymes never occur except as the result of cell life—they are produced within the cell and increased in amount by each new cell that is formed, and, furthermore, they are probably present in every living cell without exception. As the same facts are equally true of the proteids, and apparently true of nothing else, it is natural to associate the enzymes with proteids and so to explain the importance of the proteids for cell life. If enzymes are obtained in any of the usual ways from animal cells or secretions they are always found to give the reactions for proteids, even if repurified many times; but it is well