<prompt> All of the following are essential aminoacids except:MethionineLysineAlanineLeucine  <response>: Threonine, Lysine, Phenylalanine, Methionine, Isolcucine Leucine, Tryptophan, Valine Histidine Arginine are nutritionally essential amino acids. Among these last two histidine arginine are semi- essential, and arginine is more essential than histidine. 