This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Phenylalanine and Tyrosine metabolism Detail, Subject name: Biochemistry
Melanin is synthesized from : 
Select and explain. 
A. Tyrosine, B. Tryptophan, C. Phenyl alanine, D. Threonine
A: Tyrosine
Answer: A: Tyrosine 
Explanation: Synthesis of Melanin Pigment Melanin is synthesized from tyrosine by following pathway. It occurs in melanosomes present in melanocytes of skin and hair Option 2-Tryptophan forms niacin (Vit B3), serotonin and melatonin. Extra Information: Uses of tyrosine: 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.