SOME ASPECTS OF THE BIOSYNTHESIS OF AMINO ACIDS

The biosynthesis of amino acids, for the purpose of this discussion, may be separated into two main processes, namely the synthesis and source of the carbon chain and the utilization and mode of participation of the nitrogen atom. The total synthesis of an amino acid may take place either from an α-keto acid formed from metabolites other than preformed amino acids, or from organic nitrogen compounds. If a keto acid is an intermediate in the synthesis of an amino acid it would have to be reductively aminated or be involved in transamination. If the intermediate is an organic nitrogen compound, which may or may not be an amino acid, it will have to be converted into an amino acid either by a condensation reaction or by a degradative step. In the latter case the amino acid will be formed utilizing the carbon atoms and the nitrogen of the precursor and...