Amino-acid definition

An organic compound containing an amino group (NH₂ ), a carboxylic acid group (COOH), and any of various side groups, especially any of the twenty compounds that have the basic formula NH₂ CHRCOOH, and that link together by peptide bonds to form proteins or that function as chemical messengers and as intermediates in metabolism.

Any of a large group of organic acids containing a carboxyl group, COOH, and an amino group, NH₂

Any of the amino acids, usually about 20, that link together into polypeptide chains to form proteins that are necessary for all life: in general, they are water-soluble, crystalline, amphoteric electrolytes having mirror-image isomeric forms with right and left optical activity: ten of these (essential amino acids) cannot be synthesized by the human body and must be consumed.

Any of various compounds containing an amino group (NH₂ ), a carboxylic acid group (COOH), and a distinctive side chain, especially any of the 20 amino acids that link together to form proteins. Some amino acids (called nonessential) can be synthesized in the human body, while others (called essential) must be obtained through the diet.

Any of a large number of compounds found in living cells that contain carbon, oxygen, hydrogen, and nitrogen, and join together to form proteins. Amino acids contain a basic amino group (NH₂ ) and an acidic carboxyl group (COOH), both attached to the same carbon atom. Since the carboxyl group has a proton available for binding with the electrons of another atom, and the amino group has electrons available for binding with a proton from another atom, the amino acid behaves as an acid and a base simultaneously. Twenty of the naturally occurring amino acids are the building blocks of proteins, which they form by being connected to each other in chains. Eight of those twenty, called essential amino acids, cannot be synthesized in the cells of humans and must be consumed as part of the diet. The remaining twelve are nonessential amino acids.