Amino Acid, Essential

Amino acids (AA) are the building blocks of all proteins and are characterized by the presence of at least one amino group (NH2) and carboxyl or acid group (COOH), hence the name amino acid. Many amino acids are produced by the body, others called essential amino acids, cannot be synthesized by the body in adequate amounts and must be obtained from the diet. 

The essential amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Semi-essential AA (some are made by the body but not enough to meet the body's needs) are arginine, histidine, cysteine and taurine. Some disorders associated with AA imbalances include alcoholism, ataxia, behavioral disorders, cardiovascular disease, depression, insomnia, hypertension, eye problems, poor wound healing, digestive problems. Inborn errors of amino acid metabolism, includes phenylketonuria (PKU), tyrosinemia, alkaptonuria, maple syrup urine disease (MSUD), etc.

Amino acids may be ordered as a profile of Essential AA, or as Fractionated AA. The essential AA profile contains arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The fractionated AA profile includes the essential AA plus alanine, asparagine, aspartic acid, a-amino-N-butyric acid, citrulline, cystine, glutamine, glutamic acid, glycine, hydroxyproline, ornithine, proline, serine, tyrosine, and taurine.

Profile Includes Histidine; isoleucine; leucine; lysine; methionine; phenylalanine; threonine; tryptophan; valine; arginine

REFERENCES:

• Alverdy, J.C. Effects of glutamine-supplemented diets on immunology of the gut. J Parent Ent Nutr, 1990,14(4):1095-1135
• Meyer, NA, Muller, MJ, Herndon DN Nutrition support of the healing wound. New Horz, 1994,2(2):202-214
• Shih, V.E. Amino acid analysis. Physician’s guide to the laboratory diagnosis of metabolic diseases. 1996; London: Chapman and Hall Medical.