Chapters consider individual amino acids, grouped according to their metabolic origin, and discussing their biosynthesis (in plants and micro-organisms for those that are dietary essentials for human beings), major metabolic roles (mainly in human metabolism) and catabolism (again mainly in human metabolism). There is also discussion of regulatory mechanisms for all these metabolic pathways, and of metabolic and genetic diseases affecting the (human) metabolism of amino acids. Throughout the book the emphasis is on the nutritional importance of amino acids, integration and control of metabolism and metabolic and other disturbances of relevance to human biochemistry and health.