<prompt> Which is not a biological derivative of tyrosine?MelaninMelatoninEpinephrineDopamine  <response>: Uses of tyrosine: Melatonin is formed from tryptophan not from tyrosine Tip to remember:- Tyrosine smaller name - Melanin smaller name Tryptophan bigger name - Melatonin bigger name Extra information:- Phenylalanine is conveed to tyrosine by enzyme Phenylalanine Hydroxylase. Therefore tyrosine is non-essential as it can be synthesized in body from phenylalanine. Other uses of tryptophan are- Synthesis of vitamin B3 and serotonin 