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Cholesterol

Biology  Chloroplasts  Chordata

Cholesterol is a lipid found in the cell membranes of all tissues, and it is transported in the blood plasma of all animals. Cholesterol is also considered a sterol (a combination steroid and alcohol).



is small molecule, one of the steroids. It is essential to life.

cholesterol
An amphipathic lipid containing the four-ring steroid structure with a hydroxyl group on one ring; a major component of many eukaryotic membranes and precursor of steroid hormones. (Figure 5-29) ...

(high)
is a type of fat found in all animals. It is an essential part of cell membranes, and is used in the body to make bile, steroid hormones, and fat-soluble vitamins including Vitamin A, D, E and K.

Cholesterol
In animals, cholesterol is a major membrane lipid. It may be equal in amount to phospholipids.
It is similar to phospholipids in that it one end is hydrophilic, the other end is hydrophobic.

and steroids: Most mention of these two in the news is usually negative. has many biological uses, such as its occurrence in the cell membranes, and its role in forming the sheath of some neurons.

cholesterol
(kol-ess-teh-rol)
A steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids.
Chondrichthyes ...

/kə-LEST-ə-rawl/ The most important sterol in animals. It is a product of the liver and is essential to the functionality of the lipid bilayers of animal cell membranes.

Hampton RY: Cholesterol homeostasis: ESCAPe from the ER.
Davies JP, Chen FW, Ioannou YA: Transmembrane molecular pump activity of Niemann-Pick C1 protein. ...


The Biology Project > Cell Biology > Cell Membranes > Problem Set
The Biology Project
Department of Biochemistry and Molecular Biophysics
University of Arizona
May 2002
Revised: August 2004
Contact the Development Team ...

Cholesterol is also present in the membrane. It maintains the fluidity and increases the stability of the membrane. Without cholesterol the membrane would easily split apart.
Functions of a membrane it's:
Selectively permeable barrier.


What are these molecules, and how do they affect health?
Common Risk-Associated Diseases ...

Cholesterol is another important component of cell membranes embedded in the hydrophobic areas of the inner (tail-tail) region. Most bacterial cell membranes do not contain cholesterol. Cholesterol aids in the flexibility of a cell membrane.

- a steroid
Can comprise up to 50% of animal plasma membrane
Hydrophilic OH groups toward surface
Smaller than a phospholipid and less amphipathic (having both polar and non-polar regions of the molecule) ...

Cholesterol synthesis
Lipogenesis, the production of triglycerides (fats).
A bulk of the lipoproteins are synthesized in the liver.

- lipid molecule with a characteristic four-ringed steroid structure that is an important component of the plasma membranes of animal cells ...

cholesterol Steroid that is an integral part of cell membranes and a precursor to other steroidal compounds in animals.
cholinergic Type of nerve fiber that releases acetylcholine from axon terminal.

While is an essential molecule in animals, high levels of in the blood may contribute to cardiovascular disease.
Both saturated fats and trans fats exert their negative impact on health by affecting levels.

In contrast, cholesterol has a complex carbon-based ring structure, and a single hydrophilic -OH group â†'.
Molecules with both hydrophobic and hydrophilic groups are termed amphipathic.

9. Which of the following are found in the cell membrane?
a. cellulose
b. phospholipids
c.
d. proteins ...

cholesterol
choline
chromatid
chromatin
chromosomal
chromosome 1 2 3 4 5 6 7 8 9 10 11 12
chromosomes 1 2 3 4
chronic
chrysoperla
ciat ...

>"bad" ) and decreases HDL ("good" ) thus
>increasing the risk of heart attack, still the # 1 cause of death in the
>U.S.
> The text also mentioned the protective effect in females of having ...

for discovering the molecular structure of DNA 1963 Sir John Carew Eccles, Alan Lloyd Hodgkin, Andrew Fielding Huxley for describing the electric transmission of impulses along nerves 1964 Konrad Bloch, Feodor Lynen for research on cholesterol and ...

MRC/BHF Heart Protection Study of -lowering with simvastatin in 5963 people with diabetes: a randomised placebo-controlled trial. Lancet 2003;361(9374):2005-16. PMID 12814710.

Cholesterol (← links)
Diabetes insipidus (← links)
Adulterant (← links)
Pickle (← links)
Ilosvay reagent (← links)
Persulphocyanogen (← links)
Myosin (← links)
Hungary (← links)
Wormleys test (← links)
Papyrine (← links) ...

Cell membranes also contain in the phospholipid bilayer. In some membranes there are only a few molecules, but in others there are as many s as phospholipids according to Audesirk & Audesirk.

Steroid molecules and if you ever see a name of a molecule and it has the syllable ster in it like cholesterol estrogen, testosterone, ...

The cell membranes found in animal cells contain a chemical called . This chemical makes the membrane harder. Plant cells do not need , because they have a cell wall, as a result, their cell membranes are softer.

an organic compound containing four fused carbon rings, for example, cholesterol, sex hormones, vitamin D, and adrenocortical hormone (ACTH)
Source: Noland, George B. 1983. General Biology, 11th Edition. St. Louis, MO. C. V. Mosby
...

Myelin a mixture of phospholipids and which forms a sheath around many nerve cells
Myofibrils the microscopic fibres that make up the larger fibres of skeletal muscle
Myoglobin an iron-containing protein found in muscle ...

ATP in liver is used for active transport / phagocytosis / synthesise of glucose, protein, DNA, RNA, lipid, cholesterol / urea in glycolysis / bile production / cell division
Brown fat ...

Because they do that job, you would expect liver cells to have more peroxisomes than most other cells in a human body. They also play a role in synthesis and the digestion of amino acids.

And there are different types of plasma membranes in different types of cells, and the plasma membrane has in it in general a lot of cholesterol as its lipid component. That's different from certain other membranes from within the cell.

See also: See also: Cells, Trans, Protein, Blood, Organ

Biology  Chloroplasts  Chordata

 
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