Biomolecules Question 12
12. The amino acid Tryptophan is the precursor for the synthesis of
(a) Melatonin and Serotonin
(b) Thyroxine and Triiodothyronine
(c) Estrogen and Progesterone
(d) Cortisol and Cortisone
Show Answer
Answer : a
Hints & Solutions
(a) Tryptophan is a precursor to neurotransmitters serotonin and melatonin. Thyroxine (3,5,3’ ,5’-tetraiodothyronine) is produced by follicular cells of the thyroid gland. It is produced as the precursor thyroglobulin. Estrogen is biosynthesized from progesterone (in two steps from cholesterol, via intermediate pregnenolone). Cortisone is one of several endproducts of a process called steroidogenesis. Cortisol is produced in the adrenal cortex of kidney.
