<prompt> All of the following are essential amino acids exceptMethionineLysineAlanineLeucine  <response>: Alanine is a non-essential amino acid .essential amino acids are threonine valine tryptophan isoleucine lysine proline methionine TV TILL 8 PM.they are not synthesized by humans.they are required for our normal growth.Ref: DM Vasudevan - Textbook of Biochemistry for Medical Students, 7th edition, page no: 27 