MICROANATOMY

Detailed explanation-1: -Steroids are lipids because they are hydrophobic and insoluble in water, but they do not resemble lipids since they have a structure composed of four fused rings. Cholesterol is the most common steroid and is the precursor to vitamin D, testosterone, estrogen, progesterone, aldosterone, cortisol, and bile salts.

Detailed explanation-2: -Cholesterol is the sole precursor of steroids. Steroid synthesis is initiated at the inner mitochondrial membrane (IMM), where the cytochrome P450 cholesterol side chain cleavage enzyme (CYP11A1) catalyzes the conversion of cholesterol to pregnenolone [1].

Detailed explanation-3: -Cholesterol is a steroid because it shares the chemical structure of four fused carbon rings with other steroids. Specifically, it is a sterol, which is a class of lipid with an alcohol (hydroxyl) or-OH group.