. "Biosynthesis of steroid hormones which takes place in the mitochondria of the adrenal cortex. Oxidation of two adjacent carbon atoms in the side chain of cholesterol, followed by the cleavage between them, produces pregnenolone, a precursor of all other steroid hormones. The hydroxylation and oxygenation reactions are catalyzed by cytochrome P450 and mixed-functions oxidases that use NADPH and O2." . . "Steroidogenesis" . . .