This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Biochemistry
[{'content': 'Melanin is derived from which amino acid? \nSelect and explain. \nA. Tyrosine, B. Tryptophan, C. Phenylalanine, D. Alanine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Melanin is synthesized from tyrosine by following pathway. Melanin is synthesized from tyrosine by following pathway It occurs in melanosomes present in melanocytes of skin and hair Uses of tyrosine: Option B: Tryptophan forms niacin (Vit B3), serotonin and melatonin. Extra Information: Albinism - Absence of pigment from skin, hair and eyes. Defect is in enzyme Tyrosinase. Patients also have vision defects and photophobia. This is also called oculo-cutaneous albinism. Vitiligo: Lack of melanoblast in some regional areas, but enzyme Tyrosinase is normal', 'role': 'assistant'}]