An amino acid is any molecule that contains both amino and carboxylic acid functional groups. Amino acid is any one of a class of
simple organic compounds containing carbon, hydrogen, oxygen, nitrogen, and in certain cases sulfur. These compounds are the
building blocks of proteins. Amino acids are biochemical building blocks. They form short polymer chains called peptides or
polypeptides which in turn form structures called proteins. Each amino acid has at least one carboxyl (COOH) group, which is acidic,
and one amino (NH(2)) group, which is basic. Amino acids join together in long chains, the amino group of one amino acid linking
with the carboxyl group of another. The linkage is known as a peptide bond, and a chain of amino acids is known as a polypeptide.
Proteins are large, naturally occurring polypeptides.

Hundreds of different amino acids exist in nature, and about two dozen of them are important to human nutrition. Essential amino
acids are amino acids that cannot be synthesized in 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. Non-essential amino
acids are those that the body can manufacture from an available source of nitrogen and a carbon skeleton. The nonessential
amino acids are arginine, alanine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, proline, serine, and tyrosine.
Semi-essential amino acids are ones that can sometimes be made internally if conditions are right. Histidine is considered semi-
essential because the body does not always require dietary sources of it. Other amino acids, such as carnitine, are used by the body
in ways other than protein-building and are often used therapeutically.

Amino acids are needed to build the various proteins used in the growth, repair, and maintenance of body tissues. Amino acids
play innumerable roles in human health and disease. Alanine is necessary for the promotion of proper blood glucose levels from
dietary protein. Alanine stimulates lymphocyte production and may help people who have immune suppression. Alanine strengthens
the immune system by producing antibodies. L-arginine is used by the immune system to help regulate the activity of the thymus
gland, which is responsible for manufacturing T lymphocytes. The body uses arginine to produce nitric oxide. Nitric oxide is an
endogenous messenger molecule involved in a variety of endothelium-dependent physiological effects in the cardiovascular system.
In the central nervous system, asparagine is needed to maintain a balance, preventing over nervousness or being overly calm.
Aspartic acid can help protect the liver from some drug toxicity and the body from radiation.

references: 1) http://www.vitamins-supplements.org/amino-acids/ 2) http://en.wikipedia.org/wiki/Amino_acid

Chemical Zone, Chunjiang Town, Xinbei District, Changzhou, Jiangsu, China
Tel.: +86-519-8511 3273 Fax: +86-519-8513 2127 E-Mail: sales@hitrox.com