METHIONINE

The dominant interest awakened by the amino-acids in any consideration of the metabolism of proteins in the body represents one of the newer developments of biologic chemistry. Proteins, in the course of digestion, are disintegrated into their amino-acid components, which are absorbed as such and carried to the tissues, where they may experience a variety of chemical transformations, now being reconstructed into new protein or other body constituents, now further broken down and used as fuel or converted to simpler derivatives, such as sugar. Added to this story of the physiologic changes undergone by the amino-acids is the well established fact that some of them which are indispensable to the nutritive processes and to the growth of the organism cannot be synthesized de novo in the body and hence must be supplied somehow in the dietary intake. Perversions in the metabolism of the amino-acids present some of the outstanding instances