Amino acids

Human nutrition requires a source of the components of protein, carbohydrates, lipids, vitamins and minerals. Proteins are associated with all forms of life. The proteins of living matter act as organic catalysts (enzymes), as structural features of the cell, as messengers (peptide hormones), and as antibodies. Amino acids are often referred to as the building blocks of proteins. Amino acids also serve as sources of nitrogen and sulfur and can be catabolized to provide energy. There are twenty common amino acids all containing at least one carbon atom covalently bonded to a carboxyl group (COOH), an amino group (NH3), hydrogen (H) and a variable side chain (R). Amino acids are necessary for the survival of all organisms. Some amino acids are synthesized by the organism while others are provided in the diet. Enzymes transform biomolecules into amino acids, degrade amino acids, and convert amino acids from one type to another. The absence or excess of an amino acid in humans can cause a clinical disorder such as Phenylketonuria, Cystinuria, Fanconi's syndrome or Hartnup disease. It is known that the adult human requires eight amino acids which are essential for the maintenance of good health. These amino acids are isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. The essential amino acids in man are L-isoleucine, L-leucine, L-valine, L-methionine, L-phenylalanine, L-histidine, L-lysine, L-tryptophan and L-threonine. The semi-essential amino acids for man include L-tyrosine, L-cystine, and L-cysteine, which are believed to be required for optimal growth in infants. Arginine is essential in children who have defects of one of the enzymes of the urea cycle, but is not generally considered essential or semi-essential in normal man. Amino acids, in addition to their role as protein monomeric units, are energy metabolites and precursors of many biologically important nitrogen-containing compounds, notably heme, physiologically active amines, glutathione, nucleotides, and nucleotide coenzymes. Excess dietary amino acids are neither stored for future use nor excreted. Rather they are converted to common metabolic intermediates such as pyruvate, oxaloacetate, and alpha-ketoglutarate. Consequently, amino acids are also precursors of glucose, fatty acids, and ketone bodies and are therefore metabolic fuels. In nature, there are three branched chain amino acids (BCAA's): L-lsoleucine, L-Leucine and L-Valine. As mentioned above, amino acids are the building blocks of protein. These three are among those considered "essential" because they cannot be manufactured in the body and must be obtained through diet. They have been shown to provide safe nutritional support for individuals seeking optimal lean muscle mass. BCAA's play a principle role in muscle recovery, muscle growth and energy maintenance. They help increase the bioavailability of complex carbohydrate intake and are absorbed by the muscle cells for anabolic muscle building activity.