Cholesterol

 

Cholesterol, from the Ancient Greek chole- (bile) and stereos (solid) followed by the chemicalsuffix -ol for an alcohol, is an organic molecule. It is a sterol (or modified steroid),^[3] and an essential structural component of animal cell membranes that is required to establish proper membrane permeability and fluidity. Cholesterol is thus considered within the class of lipid molecules.

In addition to its importance within cells, cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acids, and vitamin D.^[4] Cholesterol is the principal sterol synthesized by animals, all cells; in vertebrates the liver typically produces greater amounts than other cells. It is almost completely absent among prokaryotes (i.e., bacteria), although there are some exceptions such as Mycoplasma, which require cholesterol for growth.^[5]

François Poulletier de la Salle first identified cholesterol in solid form in gallstones in 1769. However, it was not until 1815 that chemist Michel Eugène Chevreul named the compound "cholesterine".^[6][7]