[Biosynthesis of steroids in the adrenal gland]

Cholesterol and steroid hormone biosynthesis, enzymes which catalyze each step in the biosynthesis, their localization and the genes that encode them are presented. The simplified mechanism of the enzyme cytochrome P450 action is described. It comprises alternative oxidation and reduction of flavoprotein adrenodoxin reductase, adrenodoxin and cytochrome P450. delta 4 and delta 5 pathways for androgen biosynthesis and an alternative biosynthetic pathway for aldosterone and cortisol biosynthesis are also described.