ESSENTIALITY OF AMINO ACIDS

Not long after the demonstration, on the basis of chemical analysis, that some proteins fail to provide certain amino acids, nutritional studies with experimental animals established that growth, maintenance and physiologic well being cannot be attained unless certain amino acids are available to the animal. Indeed, the work of Hopkins and of Osborne and Mendel in this connection served to turn attention from the importance of the quantity of protein in the diet to a consideration of the biologic significance of the quality of the food proteins as regards their amino acid content. The brilliant work of Rose and his callaborators at the University of Illinois has served not only to expand the number of amino acids recognized as indispensable for adequate nutrition but also to clarify the general concept of the nutritional significance of amino acids. At present it is generally accepted that there are ten amino acids essential