Cholesterol, from the Greek chole- (bile) and stereos (solid) followed by the chemical suffix -ol for an alcohol, is an
organic chemical substance classified as a waxy steroid of
fat. It is an essential structural component of mammalian
cell membranes and is required to establish proper
membrane permeability and fluidity.
In addition to its importance within cells, cholesterol
also serves as a precursor for the biosynthesis of steroid hormones, bile acids, and vitamin D. Cholesterol is the principal sterol synthesized by animals; in vertebrates
it is formed predominantly in the liver. Small quantities
are synthesized in other cellular organisms (eukaryotes)
such as plants and fungi. It is almost completely absent
among prokaryotes (i.e., bacteria).
Although cholesterol is important and necessary for human health, high levels of cholesterol in the blood have been
linked to damage to arteries and cardiovascular disease.
Source: Internet.
