Coupled Reactions in Biological Systems

Abstract

Feeding benzoic and phenylacetic acids to animals may have no effect on total N catabolism. Glycine and glutamic acid thus lost from body are not specially synthesized for detoxication. Creatine is markedly reduced by the benzoic acid but not by phenylacetic acid. An appreciable part of normal protein catabolism is believed to go via gluta-thione. Glycine is involved in creatine formation; the guanidine group is synthetic in origin. The carboxyl group of creatine may be linked as an ester, thioxy ester, or amide, in the formation of creatinine.