part_of tryptophan metabolic pathway hydrophobic amino acid biosynthetic pathway tryptophan biosynthetic pathway 2013-05-13T11:10:00Z PW:0001280 Those metabolic reactions involved in the synthesis of tryptophan, an essential amino acid that humans cannot synthesize. Its synthesis takes place in plants and microorganisms. In plants, the synthesis of aromatic amino acids is part of the chorismate pathway, the end branch point of the shikimate pathway. pathway tryptophan biosynthetic process vpetri chorismate metabolic pathway