| umls-concept:C0041485 | skos:definition | MSH: A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.,CSP: amino acid, p-hydroxyphenylalanine, found in most proteins, synthesized metabolically from phenylalanine; a precursor of thyroid hormones, catecholamines, and melanin.,NCI: The levorotatory isomer of the aromatic amino acid tyrosine. L-tyrosine is a naturally occurring tyrosine and is synthesized in vivo from L-phenylalanine. It is considered a non-essential amino acid; however, in patients with phenylketonuria who lack phenylalanine hydroxylase and cannot convert phenylalanine into tyrosine, it is considered an essential nutrient. In vivo, tyrosine plays a role in protein synthesis and serves as a precursor for the synthesis of catecholamines, thyroxine, and melanin.,NCI: Amino acid with side chain -CH2-C6H4OH. | lld:umls |
