essential amino acid

of the 20 AMINO ACIDS required by the body, a number are termed essential because they must be included in the diet as they cannot be synthesized in the body. The essential ones are: isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. In addition, infants require arginine and histidine. A lack leads to protein deficiency, but they are available in meat, cheese and eggs, and all eight would be obtained if the diet contained corn and beans.