Sterols, or steroid alcohols are a subgroup of steroids with a hydroxyl group at the 3-position of the A-ring. [cite journal |author=Fahy E, Subramaniam S, Brown HA, "et al" |title=A comprehensive classification system for lipids |journal=J. Lipid Res. |volume=46 |issue=5 |pages=839–61 |year=2005 |pmid=15722563 |url= |doi=10.1194/jlr.E400004-JLR200] They are amphipathic lipids synthesized from acetyl-coenzyme A via the HMG-CoA reductase pathway. The overall molecule is quite flat. The hydroxyl group on the A ring is polar. The rest of the aliphatic chain is non-polar.

Sterols of plants are called "phytosterols" and sterols of animals are called "zoosterols". Important zoosterols are cholesterol and some steroid hormones; notable phytosterols include campesterol, sitosterol, and stigmasterol. Ergosterol is a sterol present in the cell membrane of fungi, where it serves a role similar to cholesterol in animal cells.

Sterols and related compounds play essential roles in the physiology of eukaryotic organisms. For example, cholesterol forms part of the cellular membrane in animals, where it affects the cell membrane's fluidity and serves as secondary messenger in developmental signaling. In humans and other animals, corticosteroids, such as cortisol act as signalling compounds in cellular communication and general metabolism.

Phytosterols may block cholesterol absorption sites in the human intestine thus helping to reduce cholesterol in humans. Fact|date=June 2008

ee also



Molecular Biology of the Cell (Alberts et al., 2002) [,bilayer&rid=mboc4.section.1864#1874]

External links

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  • sterol — STERÓL, steroli, s.m. (La pl.) Clasă de alcooli având o structură complexă, care se găsesc în alcătuirea multor vieţuitoare şi au un rol important în metabolismul organismului; (şi la sg.) substanţă din această clasă; sterină. – Din fr. stérol.… …   Dicționar Român

  • stérol — [ sterɔl ] n. m. • 1913; du suff. de cholestérol ♦ Biochim. Alcool polycyclique de masse moléculaire élevée, très répandu dans les règnes animal et végétal où il joue un rôle important. ⇒ cholestérol, ergostérol. Adj. STÉROLIQUE . ● stérol nom… …   Encyclopédie Universelle

  • sterol — [stir′ôl΄, ster′ôl΄; stir′ōl΄, ster′ōl΄] n. [< (CHOLE)STEROL] any of a group of solid cyclic unsaturated alcohols, as cholesterol, found in plant and animal tissues …   English World dictionary

  • sterol — ► NOUN Biochemistry ▪ any of a group of naturally occurring unsaturated steroid alcohols, typically waxy solids. ORIGIN independent usage of the ending of words such as CHOLESTEROL(Cf. ↑cholesterol) …   English terms dictionary

  • -sterol — sterol, suffix Biochem. (stərɒl) [f. cholesterol.] A formative element in the names of many sterols, as in ergosterol, phytosterol …   Useful english dictionary

  • Stérol — Noyau de base des stérols Cholestérol, un stérol. Un …   Wikipédia en Français

  • sterol — si·to·sterol; spi·na·sterol; sterol; …   English syllables

  • sterol — /ˈstɛrɒl/ (say sterol) noun any of a group of steroid alcohols derived from plants or animals, as cholesterol and ergosterol. {abstracted from (chole)sterol, (ergo)sterol} …   Australian English dictionary

  • Sterol — Strukturformel von Sterin (Sterol) Sterine, auch Sterole, sind eine Gruppe von biochemisch wichtigen Naturstoffen aus der Obergruppe der Steroide. Grundgerüst ist das Sterin, ein Steran mit einer 3β Hydroxygruppe. Nach ihrem Vorkommen lassen die… …   Deutsch Wikipedia

  • sterol — noun Etymology: International Scientific Vocabulary, from sterol (as in cholesterol) Date: 1913 any of various solid steroid alcohols (as cholesterol) widely distributed in animal and plant lipids …   New Collegiate Dictionary

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