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Article: Cholesterol
- Article from:
- Chemistry: Foundations and Applications
- Author:
CopyrightCOPYRIGHT 2004 The Gale Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Cholesterol
Cholesterol is the most abundant sterol in animal tissues, making up as much as 25 percent of cell membranes. Cholesterol may be found free or as part of cholesteryl
esters
. It is a
precursor molecule
for many steroid hormones, including
glucocorticoids
,
androgens
and
estrogen
, aldosterone, and mineralocorticoids. A major component of lipoproteins, it is also the precursor for bile salts and bile acids, which are necessary for digestion. Gallstones contain large amounts of cholesterol.
Cholesterol is a seventeen-carbon polycyclic compound made up of three six-membered and one five-membered fused rings. The molecule is relatively
nonpolar
and
hydrophobic
, but ...