An amino acid is an organic molecule in which a hydrogen atom, a carboxyl group, and an amino group (–NH2) are all bonded to the same alpha carbon with the side chain at the end. They can form peptide bonds. Some amino acid groups can be specifiedby the number of amino acids designated such as ooligopeptideswhich can join up to 20 amino acids and polypeptides which can join up to 50 amino acids.