Final answer:
Tetrahydrobiopterin (BH4) is a cofactor used by hydroxylase enzymes in the synthesis of several important substances, including dopamine, serotonin, catecholamines, heme, choline, creatine, glutathione, epinephrine, taurine, bile acid taurocholic acid, and threonine.
Step-by-step explanation:
Tetrahydrobiopterin (BH4) is a cofactor used by hydroxylase enzymes in the synthesis of dopamine, serotonin, catecholamines and heme. It is also involved in the synthesis of choline, creatine, glutathione, epinephrine, taurine, and bile acid taurocholic acid. Additionally, it is necessary for the synthesis of threonine and is a constituent of enzymes such as tyrosinase, cytochrome oxidase, uricase, ferroxidase I (ceruloplasmin), ferroxidase II, superoxide dismutase, amino oxidase, and dopamine hydroxylase.