<prompt> All are essential amino acid exceptPhenylalanineLysineLeucineGlycine  <response>: The essential amino acids are Isoleucine, Leucine Threonine Lysine, Methionine, Phenylalanine, Tryptophan, and Valine.Ref: DM Vasudevan - Textbook of Biochemistry for Medical Students, 7th edition, page no: 27 