Amino acids are the basic structure of proteins. The 20 different amino acids are characterized by a central carbon atom with an amino group (NH2) on one end and a carboxyl functional group (COOH) on the other end. The symbol R designates a variable side chain group which is attached to the central carbon atom.
This R group determines the chemical characteristics of the different amino acids. The amino acids are linked by amid linkages, called peptide bonds, which are formed by linking the carboxyl group of one amino acid to the amino group of the neighboring amino acid. Amino acids can be linked in different sequences to form Amino acids play an important role as the building blocks of proteins which are important in cellular processes. The chemical structure of amino acids determines the biological activity and properties of a particular protein.
The amino acid sequence is important in the folding of a protein into a three dimensional structure and in the resulting stability of the structure. Amino acids are also necessary in the formation of parts of coenzymes and they also act as precursors for the biosynthesis of molecules. Because of their central role in biochemistry, amino acids are also important in nutrition, food technology and different industries such as pharmaceutical and biodegradable plastics industries.
Classes of Biological Molecules (n.d.). Retrieved May 15, 2009, from http://www.unisanet.unisa.edu.au/08365/h&p1bmol.htm#amino_acid