Definition for Amino acid
From Biology Forums Dictionary
1. The building block of proteins. Amino acids have a common structure in which a carbon atom, called the α-carbon, is linked to an amino group (NH2) and a carboxyl group (COOH). The α-carbon also is linked to a hydrogen atom and a particular side chain.
2. a compound in which an amino group and a carboxyl group are attached to the same carbon atom.