All the amino acids that form proteins are called protein amino acids. Protein is 20 amino acids. Glycine, lysine, valine, alanine, tyrosine, leucine, isoleucine, aspartic acid, glutamic acid, asparagine, glutamine, arginine, cystine, serine, methionine, threonine, phenylalanine, histidine, tryptophan and proline.