Biochemistry. The major fatty steroid alcohol of all vertebrate cells. It is an essential component of the cell membrane and a precursor in the synthesis of steroid hormones. It is found in animal fats and oils, in liver, milk products and egg yolk. Most of the body's cholesterol is synthesized in the liver.
Cholesterol is bound to high-density lipoproteins (HDL) or low density lipoproteins (LDL) for transport in the blood. High levels of LDL-cholesterol ("bad" cholesterol) have been linked to heart disease and arteriosclerosis whereas high levels of HDL-cholesterol ("good" cholesterol) have a protective function.