The hormonal factor responsible for circadian rhythm is formed from which amino acid?: (A) Tyrosine, (B) Tryptophan, (C) Phenylalanine, (D) Histidine
Answer is B. Ans. is 'b' i.e., Tryptophan In circadian rhythm maintenance melatonin is involved which is derived from tryptophan.Tryptophan is a precursor for synthesis of niacin (nicotinic acid), serotonin and melatonin.