17-a hydroxylase is not involved in the pathway for synthesis of -

Ans. is 'b' i.e., Aldosterone o All steroid hormones originate from cholesterol.o Steps involved in biosynthesis of various steroid hormones are as followsi) Cholesterol is first acted upon by desmolase to form a 21 -carbon product pregnenolone, which is the biosynthetic precursor of all steroid hormones.ii) Pregnenolone is converted to progesterone by dehydrogenase.iii) Progesterone is further converted to glucocorticoids and mineralcorticoids by hydroxylations. These reactions are affected by monooxygenases which require cytochrome P-450 as an intermediate electrone carrier. These monooxygenases are -a) 17-hydroxylase and 21-hydroxylase - Microsomalb) 11-hydroxyalse - Mitochondrial