O que (quem) é cholesterol - definição
![[[Reference ranges for blood tests]], showing usual, as well as optimal, levels of HDL, LDL, and total cholesterol in mass and molar concentrations, is found in orange color at right, that is, among the blood constituents with the highest concentration.](https://commons.wikimedia.org/wiki/Special:FilePath/Blood values sorted by mass and molar concentration.png?width=200 "[[Reference ranges for blood tests]], showing usual, as well as optimal, levels of HDL, LDL, and total cholesterol in mass and molar concentrations, is found in orange color at right, that is, among the blood constituents with the highest concentration.")
!['''[[Substrate presentation]]'''; PLD (blue oval) is sequestered into cholesterol-dependent lipid domains (green lipids) by [[palmitoylation]]. PLD also binds PIP2(red hexagon) domains (grey shading) located in the disordered region of the cell with phosphatidylcholine (PC). When cholesterol decreases or PIP2 increases in the cell, PLD translocates to PIP2 where it is exposed to and hydrolizes PC to phosphatidic acid (red spherical lipid).](https://commons.wikimedia.org/wiki/Special:FilePath/Enzyme translocation.png?width=200 "'''[[Substrate presentation]]'''; PLD (blue oval) is sequestered into cholesterol-dependent lipid domains (green lipids) by [[palmitoylation]]. PLD also binds PIP2(red hexagon) domains (grey shading) located in the disordered region of the cell with phosphatidylcholine (PC). When cholesterol decreases or PIP2 increases in the cell, PLD translocates to PIP2 where it is exposed to and hydrolizes PC to phosphatidic acid (red spherical lipid).")
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![[[Steroidogenesis]], using cholesterol as building material](https://commons.wikimedia.org/wiki/Special:FilePath/Steroidogenesis.svg?width=200 "[[Steroidogenesis]], using cholesterol as building material")
![[[Space-filling model]] of the Cholesterol molecule](https://commons.wikimedia.org/wiki/Special:FilePath/Cholesterol Spacefill.jpeg?width=200 "[[Space-filling model]] of the Cholesterol molecule")
![Numbering of the [[steroid]] nuclei](https://commons.wikimedia.org/wiki/Special:FilePath/Steroid numbering.svg?width=200 "Numbering of the [[steroid]] nuclei")
Wikipédia
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membranes. When chemically isolated, it is a yellowish crystalline solid.
Cholesterol also serves as a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Cholesterol is the principal sterol synthesized by all animals. In vertebrates, hepatic cells typically produce the greatest amounts. It is absent among prokaryotes (bacteria and archaea), although there are some exceptions, such as Mycoplasma, which require cholesterol for growth.
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".
