ChemWiki - User contributions [en]

It07:Dichloro-Diphenyl-Trichloroethane

2007-12-06T21:17:31Z

Ikm06: Corrected lit value for Henry's Law Constant

It07:Cholesterol

2007-12-06T21:11:37Z

Ikm06: /* Supplemental Project Page */

It07:Cholesterol

2007-10-29T14:48:16Z

Ikm06:

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
<ref>Journal; Barton,D.H.R. et al.; JCPRB4; J. Chem. Soc. Perkin Trans. 1; EN; 1973; 599-603. </ref>
<ref>Journal; Freire; Ribas; ANQUBU; An. Quim.; 71; 1975; 418,421. </ref>
<ref>Journal; Vochten; Joos; JCPBAN; J. Chim. Phys. Phys. Chim. Biol.; 67; 1970; 1372,1375. </ref>
<ref>Journal; Smith; Deavenport; JOMRA4; J. Magn. Reson.; 6; 1972; 257. </ref>
<ref>Journal; Kasuga, Kazuyuki; Hatakeyama, Hyoe; Hatakeyama, Tatsuko; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 1-14. </ref>
<ref>Journal; Adams, Nathan W.; Bradshaw, Jerald S.; Bayona, Jose-Maria; Markides, Karin E.; Lee, Milton L.; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 43-60. </ref>

|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:Cholesterol structure.jpg|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| 17-(1,5-dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-
tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol
|-
| Other names
| cholest-5-en-3(beta)-ol
cholesterin
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C<sub>27</sub>H<sub>46</sub>O
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| O[C@H](C4)CC[C@@]1(C)C4=CC[C@]2([H])[C@@]([H])1 CC[C@@]3(C)[C@]([H])2CC[C@@H]3[C@H](C)CCCC(C)C
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 386.65354g/mol
|-
| Appearance
| Soft, waxy yellow solid
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 57-88-5, 474-77-1, 14868-17-8, 23820-70-4, 34026-89-6, 57759-45-2, 71869-93-7, 121155-47-3, 138456-89-0
|-
| ACX Number
| X1001660-1
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 1.067g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 148°C (421K) 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 360°C (633K)
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''<sub>a</sub>) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''<sub>b</sub>) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki><sub>D</sub>] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination<br />geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| 250°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} <br /> [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and<br />properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant ε<sub>r</sub>], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic<br />data]]
| Phase behaviour<br />Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | <small>Except where noted otherwise, data are given for<br /> materials in their [[standard state|standard state (at 25 °C, 100 kPa)]]<br />[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small>
|-
|}
{{Chem-Data_Structure}}

==Cholesterol==
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HEADER NONAME 22-Oct-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 22-Oct-07 0 NONE 4
ATOM 1 O 0 7.862 -0.699 0.647 0.00 0.00 O+0
ATOM 2 C 0 6.594 -0.363 0.080 0.00 0.00 C+0
ATOM 3 H 0 6.745 0.236 -0.818 0.00 0.00 H+0
ATOM 4 C 0 5.777 0.439 1.098 0.00 0.00 C+0
ATOM 5 C 0 5.841 -1.644 -0.281 0.00 0.00 C+0
ATOM 6 C 0 4.523 -1.290 -0.973 0.00 0.00 C+0
ATOM 7 C 0 3.635 -0.504 -0.003 0.00 0.00 C+0
ATOM 8 C 0 3.301 -1.415 1.179 0.00 0.00 C+0
ATOM 9 C 0 4.393 0.680 0.518 0.00 0.00 C+0
ATOM 10 C 0 3.937 1.898 0.501 0.00 0.00 C+0
ATOM 11 C 0 2.590 2.259 -0.055 0.00 0.00 C+0
ATOM 12 C 0 1.661 1.044 0.046 0.00 0.00 C+0
ATOM 13 H 0 1.485 0.790 1.092 0.00 0.00 H+0
ATOM 14 C 0 2.334 -0.117 -0.686 0.00 0.00 C+0
ATOM 15 H 0 2.551 0.199 -1.707 0.00 0.00 H+0
ATOM 16 C 0 1.435 -1.349 -0.746 0.00 0.00 C+0
ATOM 17 C 0 0.057 -1.020 -1.342 0.00 0.00 C+0
ATOM 18 C 0 -0.550 0.075 -0.487 0.00 0.00 C+0
ATOM 19 C 0 -0.565 -0.360 0.980 0.00 0.00 C+0
ATOM 20 C 0 0.346 1.353 -0.647 0.00 0.00 C+0
ATOM 21 H 0 0.511 1.572 -1.702 0.00 0.00 H+0
ATOM 22 C 0 -0.535 2.433 -0.010 0.00 0.00 C+0
ATOM 23 C 0 -1.952 2.084 -0.543 0.00 0.00 C+0
ATOM 24 C 0 -1.936 0.566 -0.895 0.00 0.00 C+0
ATOM 25 H 0 -2.079 0.424 -1.966 0.00 0.00 H+0
ATOM 26 C 0 -3.026 -0.171 -0.114 0.00 0.00 C+0
ATOM 27 H 0 -2.865 -0.030 0.955 0.00 0.00 H+0
ATOM 28 C 0 -2.971 -1.664 -0.445 0.00 0.00 C+0
ATOM 29 C 0 -4.397 0.387 -0.501 0.00 0.00 C+0
ATOM 30 C 0 -5.476 -0.261 0.369 0.00 0.00 C+0
ATOM 31 C 0 -6.847 0.297 -0.019 0.00 0.00 C+0
ATOM 32 C 0 -7.926 -0.351 0.851 0.00 0.00 C+0
ATOM 33 C 0 -9.279 0.296 0.550 0.00 0.00 C+0
ATOM 34 C 0 -7.997 -1.848 0.545 0.00 0.00 C+0
ATOM 35 H 0 8.303 0.134 0.860 0.00 0.00 H+0
ATOM 36 H 0 5.693 -0.125 2.027 0.00 0.00 H+0
ATOM 37 H 0 6.266 1.394 1.290 0.00 0.00 H+0
ATOM 38 H 0 6.452 -2.247 -0.953 0.00 0.00 H+0
ATOM 39 H 0 5.633 -2.211 0.626 0.00 0.00 H+0
ATOM 40 H 0 4.727 -0.681 -1.854 0.00 0.00 H+0
ATOM 41 H 0 4.013 -2.205 -1.273 0.00 0.00 H+0
ATOM 42 H 0 4.206 -1.612 1.754 0.00 0.00 H+0
ATOM 43 H 0 2.564 -0.927 1.817 0.00 0.00 H+0
ATOM 44 H 0 2.894 -2.356 0.810 0.00 0.00 H+0
ATOM 45 H 0 4.555 2.686 0.907 0.00 0.00 H+0
ATOM 46 H 0 2.170 3.087 0.516 0.00 0.00 H+0
ATOM 47 H 0 2.694 2.551 -1.100 0.00 0.00 H+0
ATOM 48 H 0 1.915 -2.111 -1.359 0.00 0.00 H+0
ATOM 49 H 0 1.301 -1.740 0.263 0.00 0.00 H+0
ATOM 50 H 0 0.171 -0.670 -2.368 0.00 0.00 H+0
ATOM 51 H 0 -0.578 -1.905 -1.319 0.00 0.00 H+0
ATOM 52 H 0 0.456 -0.540 1.316 0.00 0.00 H+0
ATOM 53 H 0 -1.014 0.426 1.588 0.00 0.00 H+0
ATOM 54 H 0 -1.148 -1.276 1.082 0.00 0.00 H+0
ATOM 55 H 0 -0.505 2.363 1.078 0.00 0.00 H+0
ATOM 56 H 0 -0.231 3.425 -0.343 0.00 0.00 H+0
ATOM 57 H 0 -2.699 2.272 0.228 0.00 0.00 H+0
ATOM 58 H 0 -2.173 2.677 -1.431 0.00 0.00 H+0
ATOM 59 H 0 -3.131 -1.805 -1.513 0.00 0.00 H+0
ATOM 60 H 0 -1.994 -2.061 -0.168 0.00 0.00 H+0
ATOM 61 H 0 -3.747 -2.188 0.112 0.00 0.00 H+0
ATOM 62 H 0 -4.406 1.466 -0.349 0.00 0.00 H+0
ATOM 63 H 0 -4.595 0.167 -1.550 0.00 0.00 H+0
ATOM 64 H 0 -5.466 -1.340 0.216 0.00 0.00 H+0
ATOM 65 H 0 -5.277 -0.041 1.418 0.00 0.00 H+0
ATOM 66 H 0 -6.856 1.376 0.134 0.00 0.00 H+0
ATOM 67 H 0 -7.045 0.077 -1.068 0.00 0.00 H+0
ATOM 68 H 0 -7.679 -0.206 1.903 0.00 0.00 H+0
ATOM 69 H 0 -9.526 0.151 -0.502 0.00 0.00 H+0
ATOM 70 H 0 -10.048 -0.166 1.170 0.00 0.00 H+0
ATOM 71 H 0 -9.229 1.363 0.768 0.00 0.00 H+0
ATOM 72 H 0 -7.032 -2.309 0.759 0.00 0.00 H+0
ATOM 73 H 0 -8.765 -2.310 1.164 0.00 0.00 H+0
ATOM 74 H 0 -8.243 -1.993 -0.507 0.00 0.00 H+0
CONECT 1 2 35 0 0 NONE 79
CONECT 2 1 3 4 5 NONE 80
CONECT 4 2 9 36 37 NONE 81
CONECT 5 2 6 38 39 NONE 82
CONECT 6 5 7 40 41 NONE 83
CONECT 7 6 14 8 9 NONE 84
CONECT 8 7 42 43 44 NONE 85
CONECT 9 7 4 10 0 NONE 86
CONECT 10 9 11 45 0 NONE 87
CONECT 11 10 12 46 47 NONE 88
CONECT 12 11 20 13 14 NONE 89
CONECT 14 12 15 7 16 NONE 90
CONECT 16 14 17 48 49 NONE 91
CONECT 17 16 18 50 51 NONE 92
CONECT 18 17 24 19 20 NONE 93
CONECT 19 18 52 53 54 NONE 94
CONECT 20 18 21 12 22 NONE 95
CONECT 22 20 23 55 56 NONE 96
CONECT 23 22 24 57 58 NONE 97
CONECT 24 23 25 18 26 NONE 98
CONECT 26 24 27 28 29 NONE 99
CONECT 28 26 59 60 61 NONE 100
CONECT 29 26 30 62 63 NONE 101
CONECT 30 29 31 64 65 NONE 102
CONECT 31 30 32 66 67 NONE 103
CONECT 32 31 33 34 68 NONE 104
CONECT 33 32 69 70 71 NONE 105
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===Introduction===

Cholesterol is a '''lipid''' with a waxy, fatty texture that doesn’t dissolve in water. To be specific, cholesterol is a sub-set of lipids known as a '''steroid'''. It can be found naturally in the bloodstream and tissue of animals (especially the liver, spinal cord and the brain) where it makes up cell membranes; is used to make vitamin D, adrenal gland hormones and sex hormones: and carries out many other functions.
It must be transported between cells by carriers known as '''lipoproteins''' because it cannot dissolve in the blood. The soft, waxy texture of cholesterol means that too much cholesterol in the diet can result in '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – which can lead to heart attack.

{| border="1"
|-
|+ ''Crystals of cholesterol shown in a false colour scanning electron micrograph.''
![[Image:Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://www.scienceclarified.com/Ca-Ch/Cholesterol.html.JPG</sub>
|}

===Types of cholesterol===

There are 3 types of cholesterol:

#Cholesterol carried around in the blood by '''Low Density Lipoproteins (LDL)''' (also known as '''''“bad”''''' cholesterol) is the most common form of cholesterol in the blood. The body needs cholesterol to work properly and cells usually absorb it from the bloodstream as they need it. However, an excess of LDL cholesterol in the bloodstream can result in an accumulation of LDL cholesterol along with other substances on the walls of arteries. This can result in a condition called '''atherosclerosis''' in which the build up of cholesterol forms '''plaque''', a tough deposit that narrows the arteries. Blood flow can be blocked if a '''clot (thrombus)''' forms near to this plaque. If this blockage is near to heart muscle, a heart attack results. If it is near to any part of the brain, it leads to a stroke. Hence, high levels of LDL increase the risk of heart disease.
#The 2nd type of cholesterol is a genetic variation of LDLs known as '''Lp(a) cholesterol'''. High levels of Lp(a) cholesterol are believed to increase the risk of heart disease by leading to atherosclerosis prematurely, although the exact reason why is not known. It is believed that Lp(a) cholesterol may react with substances contained in the lesions in the artery walls, resulting in an accumulation of fatty deposits.
#Cholesterol carried by '''High Density Lipoproteins (HDL)''' (also known as '''''“good”''''' cholesterol) accounts for approximately 25-33% of the body’s cholesterol. HDL cholesterol tends to be transported away from arteries towards the liver, en route to being passed from the body. It has also been theorised that HDL cholesterol slows the growth of plaque by removing excess LDL cholesterol build up from the plaque. Contrary to LDL cholesterol, high levels of HDL cholesterol reduces the risk of heart disease and stroke.

===Where does cholesterol come from?===

Cholesterol comes from outside and inside the human body:

*'''''Inside''''' – The liver produces approximately 1000mg of cholesterol per day (it also helps to remove any excess cholesterol in the blood). This is approximately 80% of the cholesterol present in the body.

{| border="1"
|-
|+ ''Cholesterol is found naturally around the kidneys.''
![[Image:Cholesterol kidney.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://pharmalicensing.com/.../1128004281_433bfab90eaa8.JPG</sub>
|}

*'''''Outside''''' – Food from plants doesn’t contain cholesterol, however, food obtained from animals does.

In general, the body does not need any cholesterol from outside because it makes all the cholesterol that it needs within the body. If too much cholesterol is present in the bloodstream, '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – can result, increasing the risk of heart disease. Saturated fatty acids and trans fats are the main causes of rising cholesterol levels in the blood. Cholesterol levels also tend to rise with age.

===How does the body make cholesterol?===

Cholesterol synthesis is a long, complex process. It involves several stages of the formation and subsequent conversion of intermediate compounds. This is a brief summary:
*Acetyl-CoA (CoA = coenzyme) and acetoacetyl-CoA undergo condensation to form '''Hydroxymethylglutaryl-coenzyme A (HMG-CoA)'''. The process is catalysed by HMG-CoA Synthase.
*HMG-CoA Reductase then catalyses the reduction of HMG-CoA to '''mevalonate'''. This is achieved by using NADPH to reduce the carboxyl group of hydroxymethylglutarate (HMG) (connected to the thiol of CoA via an ester linkage) to an aldehyde, followed by reduction to an alcohol. This reaction is the '''''rate determining step''''' of the whole cholesterol synthesis reaction and as such, is the reaction targeted by pharmaceutical drugs designed to control cholesterol levels in the body.
*The next stage involves two phosphate transfers from 2 ATP molecules to allow phosphorylation of the newly formed mevalonate molecule, giving a new '''pyrophosphate derivative'''. This derivative then undergoes ATP-dependent decarboxylation, with dehydration, catalysed by Pyrophosphomevolanate Decarboxylase, to form a compound called '''isopentenyl pyrophosphate'''. This newly formed compound is characterised as an isoprenoid because it is a derivative of isoprene (pictured).
*Isopentenyl pyrophosphate is then interconverted into '''dimethylallyl pyrophosphate''' by isopentenyl Pyrophosphate Isomerase, involving protonation and subsequent de-protonation. This means that there will be some molecules of isopentenyl pyrophosphate and some of dimethylallyl pyrophosphate present.
*Next, isopentenyl pyrophosphate undergoes a condensation reaction, catalysed by Prenyl Transferase, with the newly formed dimethylallyl pyrophosphate to yield a single '''geranyl pyrophosphate''' molecule. The geranyl pyrophosphate molecule then proceeds to undergo another condensation reaction with an isopentenyl pyrophosphate molecule, resulting in '''farnesyl pyrophosphate.'''
*The next stage involves synthesis of a molecule of '''squalene''', made by condensing 2 molecules of farnesyl pyrophosphate together. This condensation reaction involves reduction of NADPH and is catalysed by the catalyst Squalene Synthase.
*Squalene is oxidised to '''2,3-oxidosqualene''' (an epoxide), with the help of Squalene epoxidase (catalyst), NADPH (reductant) and O2 (oxidant, 2 molecules needed).
*Protonation of 2,3-oxidosqualene triggers a sequence of electron shifts, catalysed by Squalene Oxidocyclase, resulting in '''''cyclization'''''. This leads to the generation of the sterol '''lanosterol'''.
*The final step in cholesterol synthesis involves 19 sequential reactions, catalysed by enzymes found in the endoplasmic reticulum membranes, which convert lanosterol to the final '''cholesterol''' molecule. [http://www.jce.divched.org/Journal/Issues/2002/Mar/PlusSub/V79N03/p377.pdf Diagrams and details of these reactions]

The full synthesis, as well as diagrams that make the above description clearer and easier to understand, can be found [http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm here]

===Lowering your blood cholesterol levels===

Eating more fruits and vegetables can help, as these foods do not contain any cholesterol.

Any form of physical activity can help to reduce cholesterol levels by increasing HDL cholesterol and hence lower the risk of heart disease.
HDL cholesterol levels can also be increased through moderate drinking of alcohol – although drinking '''''too''''' much can result in dangers which outweigh the benefits.

Unsurprisingly, smoking has the opposite and undesirable effect of raising blood cholesterol levels by lowering HDL cholesterol levels and the secondary effect of causing your blood to clot more readily.

===Spectra===

{| border="1"
|-
|+ ''Mass Spectrum of Cholesterol.''
![[Image:IR Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=200#Mass-Spec</sub>
|}
|-
{| border="1"
|-
|+ ''IR spectrum of Cholesterol (KBr solution).''
![[Image:Mass spec Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC</sub>
|}
|-
{| border="1"
|-
|+ ''UV Spectrum of Cholesterol.''
![[Image:UV Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=400#UV-Vis-Spec</sub>
|}

==References==

<references/>

It07:Cholesterol

2007-10-29T14:32:37Z

Ikm06:

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:Cholesterol structure.jpg|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| 17-(1,5-dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-
tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol
|-
| Other names
| cholest-5-en-3(beta)-ol
cholesterin
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C<sub>27</sub>H<sub>46</sub>O
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| O[C@H](C4)CC[C@@]1(C)C4=CC[C@]2([H])[C@@]([H])1 CC[C@@]3(C)[C@]([H])2CC[C@@H]3[C@H](C)CCCC(C)C
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 386.65354g/mol
|-
| Appearance
| Soft, waxy yellow solid
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 57-88-5, 474-77-1, 14868-17-8, 23820-70-4, 34026-89-6, 57759-45-2, 71869-93-7, 121155-47-3, 138456-89-0
|-
| ACX Number
| X1001660-1
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 1.067g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 148°C (421K) 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 360°C (633K)
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''<sub>a</sub>) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''<sub>b</sub>) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki><sub>D</sub>] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination<br />geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| 250°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} <br /> [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and<br />properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant ε<sub>r</sub>], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic<br />data]]
| Phase behaviour<br />Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | <small>Except where noted otherwise, data are given for<br /> materials in their [[standard state|standard state (at 25 °C, 100 kPa)]]<br />[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small>
|-
|}
{{Chem-Data_Structure}}

==Cholesterol==
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HEADER NONAME 22-Oct-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 22-Oct-07 0 NONE 4
ATOM 1 O 0 7.862 -0.699 0.647 0.00 0.00 O+0
ATOM 2 C 0 6.594 -0.363 0.080 0.00 0.00 C+0
ATOM 3 H 0 6.745 0.236 -0.818 0.00 0.00 H+0
ATOM 4 C 0 5.777 0.439 1.098 0.00 0.00 C+0
ATOM 5 C 0 5.841 -1.644 -0.281 0.00 0.00 C+0
ATOM 6 C 0 4.523 -1.290 -0.973 0.00 0.00 C+0
ATOM 7 C 0 3.635 -0.504 -0.003 0.00 0.00 C+0
ATOM 8 C 0 3.301 -1.415 1.179 0.00 0.00 C+0
ATOM 9 C 0 4.393 0.680 0.518 0.00 0.00 C+0
ATOM 10 C 0 3.937 1.898 0.501 0.00 0.00 C+0
ATOM 11 C 0 2.590 2.259 -0.055 0.00 0.00 C+0
ATOM 12 C 0 1.661 1.044 0.046 0.00 0.00 C+0
ATOM 13 H 0 1.485 0.790 1.092 0.00 0.00 H+0
ATOM 14 C 0 2.334 -0.117 -0.686 0.00 0.00 C+0
ATOM 15 H 0 2.551 0.199 -1.707 0.00 0.00 H+0
ATOM 16 C 0 1.435 -1.349 -0.746 0.00 0.00 C+0
ATOM 17 C 0 0.057 -1.020 -1.342 0.00 0.00 C+0
ATOM 18 C 0 -0.550 0.075 -0.487 0.00 0.00 C+0
ATOM 19 C 0 -0.565 -0.360 0.980 0.00 0.00 C+0
ATOM 20 C 0 0.346 1.353 -0.647 0.00 0.00 C+0
ATOM 21 H 0 0.511 1.572 -1.702 0.00 0.00 H+0
ATOM 22 C 0 -0.535 2.433 -0.010 0.00 0.00 C+0
ATOM 23 C 0 -1.952 2.084 -0.543 0.00 0.00 C+0
ATOM 24 C 0 -1.936 0.566 -0.895 0.00 0.00 C+0
ATOM 25 H 0 -2.079 0.424 -1.966 0.00 0.00 H+0
ATOM 26 C 0 -3.026 -0.171 -0.114 0.00 0.00 C+0
ATOM 27 H 0 -2.865 -0.030 0.955 0.00 0.00 H+0
ATOM 28 C 0 -2.971 -1.664 -0.445 0.00 0.00 C+0
ATOM 29 C 0 -4.397 0.387 -0.501 0.00 0.00 C+0
ATOM 30 C 0 -5.476 -0.261 0.369 0.00 0.00 C+0
ATOM 31 C 0 -6.847 0.297 -0.019 0.00 0.00 C+0
ATOM 32 C 0 -7.926 -0.351 0.851 0.00 0.00 C+0
ATOM 33 C 0 -9.279 0.296 0.550 0.00 0.00 C+0
ATOM 34 C 0 -7.997 -1.848 0.545 0.00 0.00 C+0
ATOM 35 H 0 8.303 0.134 0.860 0.00 0.00 H+0
ATOM 36 H 0 5.693 -0.125 2.027 0.00 0.00 H+0
ATOM 37 H 0 6.266 1.394 1.290 0.00 0.00 H+0
ATOM 38 H 0 6.452 -2.247 -0.953 0.00 0.00 H+0
ATOM 39 H 0 5.633 -2.211 0.626 0.00 0.00 H+0
ATOM 40 H 0 4.727 -0.681 -1.854 0.00 0.00 H+0
ATOM 41 H 0 4.013 -2.205 -1.273 0.00 0.00 H+0
ATOM 42 H 0 4.206 -1.612 1.754 0.00 0.00 H+0
ATOM 43 H 0 2.564 -0.927 1.817 0.00 0.00 H+0
ATOM 44 H 0 2.894 -2.356 0.810 0.00 0.00 H+0
ATOM 45 H 0 4.555 2.686 0.907 0.00 0.00 H+0
ATOM 46 H 0 2.170 3.087 0.516 0.00 0.00 H+0
ATOM 47 H 0 2.694 2.551 -1.100 0.00 0.00 H+0
ATOM 48 H 0 1.915 -2.111 -1.359 0.00 0.00 H+0
ATOM 49 H 0 1.301 -1.740 0.263 0.00 0.00 H+0
ATOM 50 H 0 0.171 -0.670 -2.368 0.00 0.00 H+0
ATOM 51 H 0 -0.578 -1.905 -1.319 0.00 0.00 H+0
ATOM 52 H 0 0.456 -0.540 1.316 0.00 0.00 H+0
ATOM 53 H 0 -1.014 0.426 1.588 0.00 0.00 H+0
ATOM 54 H 0 -1.148 -1.276 1.082 0.00 0.00 H+0
ATOM 55 H 0 -0.505 2.363 1.078 0.00 0.00 H+0
ATOM 56 H 0 -0.231 3.425 -0.343 0.00 0.00 H+0
ATOM 57 H 0 -2.699 2.272 0.228 0.00 0.00 H+0
ATOM 58 H 0 -2.173 2.677 -1.431 0.00 0.00 H+0
ATOM 59 H 0 -3.131 -1.805 -1.513 0.00 0.00 H+0
ATOM 60 H 0 -1.994 -2.061 -0.168 0.00 0.00 H+0
ATOM 61 H 0 -3.747 -2.188 0.112 0.00 0.00 H+0
ATOM 62 H 0 -4.406 1.466 -0.349 0.00 0.00 H+0
ATOM 63 H 0 -4.595 0.167 -1.550 0.00 0.00 H+0
ATOM 64 H 0 -5.466 -1.340 0.216 0.00 0.00 H+0
ATOM 65 H 0 -5.277 -0.041 1.418 0.00 0.00 H+0
ATOM 66 H 0 -6.856 1.376 0.134 0.00 0.00 H+0
ATOM 67 H 0 -7.045 0.077 -1.068 0.00 0.00 H+0
ATOM 68 H 0 -7.679 -0.206 1.903 0.00 0.00 H+0
ATOM 69 H 0 -9.526 0.151 -0.502 0.00 0.00 H+0
ATOM 70 H 0 -10.048 -0.166 1.170 0.00 0.00 H+0
ATOM 71 H 0 -9.229 1.363 0.768 0.00 0.00 H+0
ATOM 72 H 0 -7.032 -2.309 0.759 0.00 0.00 H+0
ATOM 73 H 0 -8.765 -2.310 1.164 0.00 0.00 H+0
ATOM 74 H 0 -8.243 -1.993 -0.507 0.00 0.00 H+0
CONECT 1 2 35 0 0 NONE 79
CONECT 2 1 3 4 5 NONE 80
CONECT 4 2 9 36 37 NONE 81
CONECT 5 2 6 38 39 NONE 82
CONECT 6 5 7 40 41 NONE 83
CONECT 7 6 14 8 9 NONE 84
CONECT 8 7 42 43 44 NONE 85
CONECT 9 7 4 10 0 NONE 86
CONECT 10 9 11 45 0 NONE 87
CONECT 11 10 12 46 47 NONE 88
CONECT 12 11 20 13 14 NONE 89
CONECT 14 12 15 7 16 NONE 90
CONECT 16 14 17 48 49 NONE 91
CONECT 17 16 18 50 51 NONE 92
CONECT 18 17 24 19 20 NONE 93
CONECT 19 18 52 53 54 NONE 94
CONECT 20 18 21 12 22 NONE 95
CONECT 22 20 23 55 56 NONE 96
CONECT 23 22 24 57 58 NONE 97
CONECT 24 23 25 18 26 NONE 98
CONECT 26 24 27 28 29 NONE 99
CONECT 28 26 59 60 61 NONE 100
CONECT 29 26 30 62 63 NONE 101
CONECT 30 29 31 64 65 NONE 102
CONECT 31 30 32 66 67 NONE 103
CONECT 32 31 33 34 68 NONE 104
CONECT 33 32 69 70 71 NONE 105
CONECT 34 32 72 73 74 NONE 106
END NONE 107

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===Introduction===

Cholesterol is a '''lipid''' with a waxy, fatty texture that doesn’t dissolve in water. To be specific, cholesterol is a sub-set of lipids known as a '''steroid'''. It can be found naturally in the bloodstream and tissue of animals (especially the liver, spinal cord and the brain) where it makes up cell membranes; is used to make vitamin D, adrenal gland hormones and sex hormones: and carries out many other functions.
It must be transported between cells by carriers known as '''lipoproteins''' because it cannot dissolve in the blood. The soft, waxy texture of cholesterol means that too much cholesterol in the diet can result in '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – which can lead to heart attack.

{| border="1"
|-
|+ ''Crystals of cholesterol shown in a false colour scanning electron micrograph.''
![[Image:Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://www.scienceclarified.com/Ca-Ch/Cholesterol.html.JPG</sub>
|}

===Types of cholesterol===

There are 3 types of cholesterol:

#Cholesterol carried around in the blood by '''Low Density Lipoproteins (LDL)''' (also known as '''''“bad”''''' cholesterol) is the most common form of cholesterol in the blood. The body needs cholesterol to work properly and cells usually absorb it from the bloodstream as they need it. However, an excess of LDL cholesterol in the bloodstream can result in an accumulation of LDL cholesterol along with other substances on the walls of arteries. This can result in a condition called '''atherosclerosis''' in which the build up of cholesterol forms '''plaque''', a tough deposit that narrows the arteries. Blood flow can be blocked if a '''clot (thrombus)''' forms near to this plaque. If this blockage is near to heart muscle, a heart attack results. If it is near to any part of the brain, it leads to a stroke. Hence, high levels of LDL increase the risk of heart disease.
#The 2nd type of cholesterol is a genetic variation of LDLs known as '''Lp(a) cholesterol'''. High levels of Lp(a) cholesterol are believed to increase the risk of heart disease by leading to atherosclerosis prematurely, although the exact reason why is not known. It is believed that Lp(a) cholesterol may react with substances contained in the lesions in the artery walls, resulting in an accumulation of fatty deposits.
#Cholesterol carried by '''High Density Lipoproteins (HDL)''' (also known as '''''“good”''''' cholesterol) accounts for approximately 25-33% of the body’s cholesterol. HDL cholesterol tends to be transported away from arteries towards the liver, en route to being passed from the body. It has also been theorised that HDL cholesterol slows the growth of plaque by removing excess LDL cholesterol build up from the plaque. Contrary to LDL cholesterol, high levels of HDL cholesterol reduces the risk of heart disease and stroke.

===Where does cholesterol come from?===

Cholesterol comes from outside and inside the human body:

*'''''Inside''''' – The liver produces approximately 1000mg of cholesterol per day (it also helps to remove any excess cholesterol in the blood). This is approximately 80% of the cholesterol present in the body.

{| border="1"
|-
|+ ''Cholesterol is found naturally around the kidneys.''
![[Image:Cholesterol kidney.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://pharmalicensing.com/.../1128004281_433bfab90eaa8.JPG</sub>
|}

*'''''Outside''''' – Food from plants doesn’t contain cholesterol, however, food obtained from animals does.

In general, the body does not need any cholesterol from outside because it makes all the cholesterol that it needs within the body. If too much cholesterol is present in the bloodstream, '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – can result, increasing the risk of heart disease. Saturated fatty acids and trans fats are the main causes of rising cholesterol levels in the blood. Cholesterol levels also tend to rise with age.

===How does the body make cholesterol?===

Cholesterol synthesis is a long, complex process. It involves several stages of the formation and subsequent conversion of intermediate compounds. This is a brief summary:
*Acetyl-CoA (CoA = coenzyme) and acetoacetyl-CoA undergo condensation to form '''Hydroxymethylglutaryl-coenzyme A (HMG-CoA)'''. The process is catalysed by HMG-CoA Synthase.
*HMG-CoA Reductase then catalyses the reduction of HMG-CoA to '''mevalonate'''. This is achieved by using NADPH to reduce the carboxyl group of hydroxymethylglutarate (HMG) (connected to the thiol of CoA via an ester linkage) to an aldehyde, followed by reduction to an alcohol. This reaction is the '''''rate determining step''''' of the whole cholesterol synthesis reaction and as such, is the reaction targeted by pharmaceutical drugs designed to control cholesterol levels in the body.
*The next stage involves two phosphate transfers from 2 ATP molecules to allow phosphorylation of the newly formed mevalonate molecule, giving a new '''pyrophosphate derivative'''. This derivative then undergoes ATP-dependent decarboxylation, with dehydration, catalysed by Pyrophosphomevolanate Decarboxylase, to form a compound called '''isopentenyl pyrophosphate'''. This newly formed compound is characterised as an isoprenoid because it is a derivative of isoprene (pictured).
*Isopentenyl pyrophosphate is then interconverted into '''dimethylallyl pyrophosphate''' by isopentenyl Pyrophosphate Isomerase, involving protonation and subsequent de-protonation. This means that there will be some molecules of isopentenyl pyrophosphate and some of dimethylallyl pyrophosphate present.
*Next, isopentenyl pyrophosphate undergoes a condensation reaction, catalysed by Prenyl Transferase, with the newly formed dimethylallyl pyrophosphate to yield a single '''geranyl pyrophosphate''' molecule. The geranyl pyrophosphate molecule then proceeds to undergo another condensation reaction with an isopentenyl pyrophosphate molecule, resulting in '''farnesyl pyrophosphate.'''
*The next stage involves synthesis of a molecule of '''squalene''', made by condensing 2 molecules of farnesyl pyrophosphate together. This condensation reaction involves reduction of NADPH and is catalysed by the catalyst Squalene Synthase.
*Squalene is oxidised to '''2,3-oxidosqualene''' (an epoxide), with the help of Squalene epoxidase (catalyst), NADPH (reductant) and O2 (oxidant, 2 molecules needed).
*Protonation of 2,3-oxidosqualene triggers a sequence of electron shifts, catalysed by Squalene Oxidocyclase, resulting in '''''cyclization'''''. This leads to the generation of the sterol '''lanosterol'''.
*The final step in cholesterol synthesis involves 19 sequential reactions, catalysed by enzymes found in the endoplasmic reticulum membranes, which convert lanosterol to the final '''cholesterol''' molecule. [http://www.jce.divched.org/Journal/Issues/2002/Mar/PlusSub/V79N03/p377.pdf Diagrams and details of these reactions]

The full synthesis, as well as diagrams that make the above description clearer and easier to understand, can be found [http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm here]

===Lowering your blood cholesterol levels===

Eating more fruits and vegetables can help, as these foods do not contain any cholesterol.

Any form of physical activity can help to reduce cholesterol levels by increasing HDL cholesterol and hence lower the risk of heart disease.
HDL cholesterol levels can also be increased through moderate drinking of alcohol – although drinking '''''too''''' much can result in dangers which outweigh the benefits.

Unsurprisingly, smoking has the opposite and undesirable effect of raising blood cholesterol levels by lowering HDL cholesterol levels and the secondary effect of causing your blood to clot more readily.

===Spectra===

{| border="1"
|-
|+ ''Mass Spectrum of Cholesterol.''
![[Image:IR Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=200#Mass-Spec</sub>
|}
|-
{| border="1"
|-
|+ ''IR spectrum of Cholesterol (KBr solution).''
![[Image:Mass spec Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC</sub>
|}
|-
{| border="1"
|-
|+ ''UV Spectrum of Cholesterol.''
![[Image:UV Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=400#UV-Vis-Spec</sub>
|}

==References==

#Journal; Barton,D.H.R. et al.; JCPRB4; J. Chem. Soc. Perkin Trans. 1; EN; 1973; 599-603.
#Journal; Freire; Ribas; ANQUBU; An. Quim.; 71; 1975; 418,421.
#Journal; Vochten; Joos; JCPBAN; J. Chim. Phys. Phys. Chim. Biol.; 67; 1970; 1372,1375.
#Journal; Smith; Deavenport; JOMRA4; J. Magn. Reson.; 6; 1972; 257.
#Journal; Kasuga, Kazuyuki; Hatakeyama, Hyoe; Hatakeyama, Tatsuko; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 1-14.
#Journal; Adams, Nathan W.; Bradshaw, Jerald S.; Bayona, Jose-Maria; Markides, Karin E.; Lee, Milton L.; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 43-60.
#http://www.americanheart.org/presenter.jhtml?identifier=4488
#http://www.nlm.nih.gov/medlineplus/cholesterol.html
#www.scienceclarified.com/Ca-Ch/Cholesterol.html
#http://heart.health.ivillage.com/cholesterol/cholesterol.cfm
#http://chemfinder.cambridgesoft.com/result.asp
#http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5997
#http://pharmalicensing.com/articles/disp/1128004281_433bfab90eaa8
#http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm
#Journal; Risley, John M. Cholesterol biosynthesis: lanosterol to cholesterol. Journal of Chemical Education (2002), 79(3), 377-384. CODEN: JCEDA8 ISSN:0021-9584. CAN 136:290557 AN 2002:149495 CAPLUS
#http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=200#Mass-Spec
#http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC
#http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=400#UV-Vis-Spec

It07:Cholesterol

2007-10-29T14:28:52Z

Ikm06:

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:Cholesterol structure.jpg|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| 17-(1,5-dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-
tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol
|-
| Other names
| cholest-5-en-3(beta)-ol
cholesterin
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C<sub>27</sub>H<sub>46</sub>O
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| O[C@H](C4)CC[C@@]1(C)C4=CC[C@]2([H])[C@@]([H])1 CC[C@@]3(C)[C@]([H])2CC[C@@H]3[C@H](C)CCCC(C)C
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 386.65354g/mol
|-
| Appearance
| Soft, waxy yellow solid
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 57-88-5, 474-77-1, 14868-17-8, 23820-70-4, 34026-89-6, 57759-45-2, 71869-93-7, 121155-47-3, 138456-89-0
|-
| ACX Number
| X1001660-1
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 1.067g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 148°C (421K) 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 360°C (633K)
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''<sub>a</sub>) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''<sub>b</sub>) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki><sub>D</sub>] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination<br />geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| 250°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} <br /> [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and<br />properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant ε<sub>r</sub>], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic<br />data]]
| Phase behaviour<br />Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | <small>Except where noted otherwise, data are given for<br /> materials in their [[standard state|standard state (at 25 °C, 100 kPa)]]<br />[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small>
|-
|}
{{Chem-Data_Structure}}

==Cholesterol==
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<size>300</size>
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<inlineContents>cholesterol.pdb
HEADER NONAME 22-Oct-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 22-Oct-07 0 NONE 4
ATOM 1 O 0 7.862 -0.699 0.647 0.00 0.00 O+0
ATOM 2 C 0 6.594 -0.363 0.080 0.00 0.00 C+0
ATOM 3 H 0 6.745 0.236 -0.818 0.00 0.00 H+0
ATOM 4 C 0 5.777 0.439 1.098 0.00 0.00 C+0
ATOM 5 C 0 5.841 -1.644 -0.281 0.00 0.00 C+0
ATOM 6 C 0 4.523 -1.290 -0.973 0.00 0.00 C+0
ATOM 7 C 0 3.635 -0.504 -0.003 0.00 0.00 C+0
ATOM 8 C 0 3.301 -1.415 1.179 0.00 0.00 C+0
ATOM 9 C 0 4.393 0.680 0.518 0.00 0.00 C+0
ATOM 10 C 0 3.937 1.898 0.501 0.00 0.00 C+0
ATOM 11 C 0 2.590 2.259 -0.055 0.00 0.00 C+0
ATOM 12 C 0 1.661 1.044 0.046 0.00 0.00 C+0
ATOM 13 H 0 1.485 0.790 1.092 0.00 0.00 H+0
ATOM 14 C 0 2.334 -0.117 -0.686 0.00 0.00 C+0
ATOM 15 H 0 2.551 0.199 -1.707 0.00 0.00 H+0
ATOM 16 C 0 1.435 -1.349 -0.746 0.00 0.00 C+0
ATOM 17 C 0 0.057 -1.020 -1.342 0.00 0.00 C+0
ATOM 18 C 0 -0.550 0.075 -0.487 0.00 0.00 C+0
ATOM 19 C 0 -0.565 -0.360 0.980 0.00 0.00 C+0
ATOM 20 C 0 0.346 1.353 -0.647 0.00 0.00 C+0
ATOM 21 H 0 0.511 1.572 -1.702 0.00 0.00 H+0
ATOM 22 C 0 -0.535 2.433 -0.010 0.00 0.00 C+0
ATOM 23 C 0 -1.952 2.084 -0.543 0.00 0.00 C+0
ATOM 24 C 0 -1.936 0.566 -0.895 0.00 0.00 C+0
ATOM 25 H 0 -2.079 0.424 -1.966 0.00 0.00 H+0
ATOM 26 C 0 -3.026 -0.171 -0.114 0.00 0.00 C+0
ATOM 27 H 0 -2.865 -0.030 0.955 0.00 0.00 H+0
ATOM 28 C 0 -2.971 -1.664 -0.445 0.00 0.00 C+0
ATOM 29 C 0 -4.397 0.387 -0.501 0.00 0.00 C+0
ATOM 30 C 0 -5.476 -0.261 0.369 0.00 0.00 C+0
ATOM 31 C 0 -6.847 0.297 -0.019 0.00 0.00 C+0
ATOM 32 C 0 -7.926 -0.351 0.851 0.00 0.00 C+0
ATOM 33 C 0 -9.279 0.296 0.550 0.00 0.00 C+0
ATOM 34 C 0 -7.997 -1.848 0.545 0.00 0.00 C+0
ATOM 35 H 0 8.303 0.134 0.860 0.00 0.00 H+0
ATOM 36 H 0 5.693 -0.125 2.027 0.00 0.00 H+0
ATOM 37 H 0 6.266 1.394 1.290 0.00 0.00 H+0
ATOM 38 H 0 6.452 -2.247 -0.953 0.00 0.00 H+0
ATOM 39 H 0 5.633 -2.211 0.626 0.00 0.00 H+0
ATOM 40 H 0 4.727 -0.681 -1.854 0.00 0.00 H+0
ATOM 41 H 0 4.013 -2.205 -1.273 0.00 0.00 H+0
ATOM 42 H 0 4.206 -1.612 1.754 0.00 0.00 H+0
ATOM 43 H 0 2.564 -0.927 1.817 0.00 0.00 H+0
ATOM 44 H 0 2.894 -2.356 0.810 0.00 0.00 H+0
ATOM 45 H 0 4.555 2.686 0.907 0.00 0.00 H+0
ATOM 46 H 0 2.170 3.087 0.516 0.00 0.00 H+0
ATOM 47 H 0 2.694 2.551 -1.100 0.00 0.00 H+0
ATOM 48 H 0 1.915 -2.111 -1.359 0.00 0.00 H+0
ATOM 49 H 0 1.301 -1.740 0.263 0.00 0.00 H+0
ATOM 50 H 0 0.171 -0.670 -2.368 0.00 0.00 H+0
ATOM 51 H 0 -0.578 -1.905 -1.319 0.00 0.00 H+0
ATOM 52 H 0 0.456 -0.540 1.316 0.00 0.00 H+0
ATOM 53 H 0 -1.014 0.426 1.588 0.00 0.00 H+0
ATOM 54 H 0 -1.148 -1.276 1.082 0.00 0.00 H+0
ATOM 55 H 0 -0.505 2.363 1.078 0.00 0.00 H+0
ATOM 56 H 0 -0.231 3.425 -0.343 0.00 0.00 H+0
ATOM 57 H 0 -2.699 2.272 0.228 0.00 0.00 H+0
ATOM 58 H 0 -2.173 2.677 -1.431 0.00 0.00 H+0
ATOM 59 H 0 -3.131 -1.805 -1.513 0.00 0.00 H+0
ATOM 60 H 0 -1.994 -2.061 -0.168 0.00 0.00 H+0
ATOM 61 H 0 -3.747 -2.188 0.112 0.00 0.00 H+0
ATOM 62 H 0 -4.406 1.466 -0.349 0.00 0.00 H+0
ATOM 63 H 0 -4.595 0.167 -1.550 0.00 0.00 H+0
ATOM 64 H 0 -5.466 -1.340 0.216 0.00 0.00 H+0
ATOM 65 H 0 -5.277 -0.041 1.418 0.00 0.00 H+0
ATOM 66 H 0 -6.856 1.376 0.134 0.00 0.00 H+0
ATOM 67 H 0 -7.045 0.077 -1.068 0.00 0.00 H+0
ATOM 68 H 0 -7.679 -0.206 1.903 0.00 0.00 H+0
ATOM 69 H 0 -9.526 0.151 -0.502 0.00 0.00 H+0
ATOM 70 H 0 -10.048 -0.166 1.170 0.00 0.00 H+0
ATOM 71 H 0 -9.229 1.363 0.768 0.00 0.00 H+0
ATOM 72 H 0 -7.032 -2.309 0.759 0.00 0.00 H+0
ATOM 73 H 0 -8.765 -2.310 1.164 0.00 0.00 H+0
ATOM 74 H 0 -8.243 -1.993 -0.507 0.00 0.00 H+0
CONECT 1 2 35 0 0 NONE 79
CONECT 2 1 3 4 5 NONE 80
CONECT 4 2 9 36 37 NONE 81
CONECT 5 2 6 38 39 NONE 82
CONECT 6 5 7 40 41 NONE 83
CONECT 7 6 14 8 9 NONE 84
CONECT 8 7 42 43 44 NONE 85
CONECT 9 7 4 10 0 NONE 86
CONECT 10 9 11 45 0 NONE 87
CONECT 11 10 12 46 47 NONE 88
CONECT 12 11 20 13 14 NONE 89
CONECT 14 12 15 7 16 NONE 90
CONECT 16 14 17 48 49 NONE 91
CONECT 17 16 18 50 51 NONE 92
CONECT 18 17 24 19 20 NONE 93
CONECT 19 18 52 53 54 NONE 94
CONECT 20 18 21 12 22 NONE 95
CONECT 22 20 23 55 56 NONE 96
CONECT 23 22 24 57 58 NONE 97
CONECT 24 23 25 18 26 NONE 98
CONECT 26 24 27 28 29 NONE 99
CONECT 28 26 59 60 61 NONE 100
CONECT 29 26 30 62 63 NONE 101
CONECT 30 29 31 64 65 NONE 102
CONECT 31 30 32 66 67 NONE 103
CONECT 32 31 33 34 68 NONE 104
CONECT 33 32 69 70 71 NONE 105
CONECT 34 32 72 73 74 NONE 106
END NONE 107

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===Introduction===

Cholesterol is a '''lipid''' with a waxy, fatty texture that doesn’t dissolve in water. To be specific, cholesterol is a sub-set of lipids known as a '''steroid'''. It can be found naturally in the bloodstream and tissue of animals (especially the liver, spinal cord and the brain) where it makes up cell membranes; is used to make vitamin D, adrenal gland hormones and sex hormones: and carries out many other functions.
It must be transported between cells by carriers known as '''lipoproteins''' because it cannot dissolve in the blood. The soft, waxy texture of cholesterol means that too much cholesterol in the diet can result in '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – which can lead to heart attack.

{| border="1"
|-
|+ ''Crystals of cholesterol shown in a false colour scanning electron micrograph.''
![[Image:Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://www.scienceclarified.com/Ca-Ch/Cholesterol.html.JPG</sub>
|}

===Types of cholesterol===

There are 3 types of cholesterol:

#Cholesterol carried around in the blood by '''Low Density Lipoproteins (LDL)''' (also known as '''''“bad”''''' cholesterol) is the most common form of cholesterol in the blood. The body needs cholesterol to work properly and cells usually absorb it from the bloodstream as they need it. However, an excess of LDL cholesterol in the bloodstream can result in an accumulation of LDL cholesterol along with other substances on the walls of arteries. This can result in a condition called '''atherosclerosis''' in which the build up of cholesterol forms '''plaque''', a tough deposit that narrows the arteries. Blood flow can be blocked if a '''clot (thrombus)''' forms near to this plaque. If this blockage is near to heart muscle, a heart attack results. If it is near to any part of the brain, it leads to a stroke. Hence, high levels of LDL increase the risk of heart disease.
#The 2nd type of cholesterol is a genetic variation of LDLs known as '''Lp(a) cholesterol'''. High levels of Lp(a) cholesterol are believed to increase the risk of heart disease by leading to atherosclerosis prematurely, although the exact reason why is not known. It is believed that Lp(a) cholesterol may react with substances contained in the lesions in the artery walls, resulting in an accumulation of fatty deposits.
#Cholesterol carried by '''High Density Lipoproteins (HDL)''' (also known as '''''“good”''''' cholesterol) accounts for approximately 25-33% of the body’s cholesterol. HDL cholesterol tends to be transported away from arteries towards the liver, en route to being passed from the body. It has also been theorised that HDL cholesterol slows the growth of plaque by removing excess LDL cholesterol build up from the plaque. Contrary to LDL cholesterol, high levels of HDL cholesterol reduces the risk of heart disease and stroke.

===Where does cholesterol come from?===

Cholesterol comes from outside and inside the human body:

*'''''Inside''''' – The liver produces approximately 1000mg of cholesterol per day (it also helps to remove any excess cholesterol in the blood). This is approximately 80% of the cholesterol present in the body.

{| border="1"
|-
|+ ''Cholesterol is found naturally around the kidneys.''
![[Image:Cholesterol kidney.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://pharmalicensing.com/.../1128004281_433bfab90eaa8.JPG</sub>
|}

*'''''Outside''''' – Food from plants doesn’t contain cholesterol, however, food obtained from animals does.

In general, the body does not need any cholesterol from outside because it makes all the cholesterol that it needs within the body. If too much cholesterol is present in the bloodstream, '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – can result, increasing the risk of heart disease. Saturated fatty acids and trans fats are the main causes of rising cholesterol levels in the blood. Cholesterol levels also tend to rise with age.

===How does the body make cholesterol?===

Cholesterol synthesis is a long, complex process. It involves several stages of the formation and subsequent conversion of intermediate compounds. This is a brief summary:
*Acetyl-CoA (CoA = coenzyme) and acetoacetyl-CoA undergo condensation to form '''Hydroxymethylglutaryl-coenzyme A (HMG-CoA)'''. The process is catalysed by HMG-CoA Synthase.
*HMG-CoA Reductase then catalyses the reduction of HMG-CoA to '''mevalonate'''. This is achieved by using NADPH to reduce the carboxyl group of hydroxymethylglutarate (HMG) (connected to the thiol of CoA via an ester linkage) to an aldehyde, followed by reduction to an alcohol. This reaction is the '''''rate determining step''''' of the whole cholesterol synthesis reaction and as such, is the reaction targeted by pharmaceutical drugs designed to control cholesterol levels in the body.
*The next stage involves two phosphate transfers from 2 ATP molecules to allow phosphorylation of the newly formed mevalonate molecule, giving a new '''pyrophosphate derivative'''. This derivative then undergoes ATP-dependent decarboxylation, with dehydration, catalysed by Pyrophosphomevolanate Decarboxylase, to form a compound called '''isopentenyl pyrophosphate'''. This newly formed compound is characterised as an isoprenoid because it is a derivative of isoprene (pictured).
*Isopentenyl pyrophosphate is then interconverted into '''dimethylallyl pyrophosphate''' by isopentenyl Pyrophosphate Isomerase, involving protonation and subsequent de-protonation. This means that there will be some molecules of isopentenyl pyrophosphate and some of dimethylallyl pyrophosphate present.
*Next, isopentenyl pyrophosphate undergoes a condensation reaction, catalysed by Prenyl Transferase, with the newly formed dimethylallyl pyrophosphate to yield a single '''geranyl pyrophosphate''' molecule. The geranyl pyrophosphate molecule then proceeds to undergo another condensation reaction with an isopentenyl pyrophosphate molecule, resulting in '''farnesyl pyrophosphate.'''
*The next stage involves synthesis of a molecule of '''squalene''', made by condensing 2 molecules of farnesyl pyrophosphate together. This condensation reaction involves reduction of NADPH and is catalysed by the catalyst Squalene Synthase.
*Squalene is oxidised to '''2,3-oxidosqualene''' (an epoxide), with the help of Squalene epoxidase (catalyst), NADPH (reductant) and O2 (oxidant, 2 molecules needed).
*Protonation of 2,3-oxidosqualene triggers a sequence of electron shifts, catalysed by Squalene Oxidocyclase, resulting in '''''cyclization'''''. This leads to the generation of the sterol '''lanosterol'''.
*The final step in cholesterol synthesis involves 19 sequential reactions, catalysed by enzymes found in the endoplasmic reticulum membranes, which convert lanosterol to the final '''cholesterol''' molecule. [http://www.jce.divched.org/Journal/Issues/2002/Mar/PlusSub/V79N03/p377.pdf Diagrams and details of these reactions]

The full synthesis, as well as diagrams that make the above description clearer and easier to understand, can be found [http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm here]

===Lowering your blood cholesterol levels===

Eating more fruits and vegetables can help, as these foods do not contain any cholesterol.

Any form of physical activity can help to reduce cholesterol levels by increasing HDL cholesterol and hence lower the risk of heart disease.
HDL cholesterol levels can also be increased through moderate drinking of alcohol – although drinking '''''too''''' much can result in dangers which outweigh the benefits.

Unsurprisingly, smoking has the opposite and undesirable effect of raising blood cholesterol levels by lowering HDL cholesterol levels and the secondary effect of causing your blood to clot more readily.

===Spectra===

{| border="1"
|-
|+ ''Mass Spectrum of Cholesterol.''
![[Image:IR Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=200#Mass-Spec</sub>
|}
|-
{| border="1"
|-
|+ ''IR spectrum of Cholesterol (KBr solution).''
![[Image:Mass spec Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC</sub>
|}
|-
{| border="1"
|-
|+ ''UV Spectrum of Cholesterol.''
![[Image:UV Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=400#UV-Vis-Spec</sub>
|}

==References==

#Journal; Barton,D.H.R. et al.; JCPRB4; J. Chem. Soc. Perkin Trans. 1; EN; 1973; 599-603.
#Journal; Freire; Ribas; ANQUBU; An. Quim.; 71; 1975; 418,421.
#Journal; Vochten; Joos; JCPBAN; J. Chim. Phys. Phys. Chim. Biol.; 67; 1970; 1372,1375.
#Journal; Smith; Deavenport; JOMRA4; J. Magn. Reson.; 6; 1972; 257.
#Journal; Kasuga, Kazuyuki; Hatakeyama, Hyoe; Hatakeyama, Tatsuko; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 1-14.
#Journal; Adams, Nathan W.; Bradshaw, Jerald S.; Bayona, Jose-Maria; Markides, Karin E.; Lee, Milton L.; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 43-60.
#http://www.americanheart.org/presenter.jhtml?identifier=4488
#http://www.nlm.nih.gov/medlineplus/cholesterol.html
#www.scienceclarified.com/Ca-Ch/Cholesterol.html
#http://heart.health.ivillage.com/cholesterol/cholesterol.cfm
#http://chemfinder.cambridgesoft.com/result.asp
#http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5997
#http://pharmalicensing.com/articles/disp/1128004281_433bfab90eaa8
#http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm
#Risley, John M. Cholesterol biosynthesis: lanosterol to cholesterol. Journal of Chemical Education (2002), 79(3), 377-384. CODEN: JCEDA8 ISSN:0021-9584. CAN 136:290557 AN 2002:149495 CAPLUS
#http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=200#Mass-Spec
#http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC
#http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=400#UV-Vis-Spec

It07:Cholesterol

2007-10-29T14:23:09Z

Ikm06:

<noinclude>

</noinclude>{| class="toccolours" border="1" style="float: right; clear: right; margin: 0 0 1em 1em; border-collapse: collapse; width: 280px"
! {{chembox header}} | {{PAGENAME}} 
|-
| align="center" colspan="2" bgcolor="#ffffff" | [[Image:Cholesterol structure.jpg|200px|{{PAGENAME}}]] 
|-
! {{chembox header}} | General
|-
| [http://en.wikipedia.org/wiki/IUPAC Systematic name]
| 17-(1,5-dimethyl-hexyl)-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-
tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol
|-
| Other names
| cholest-5-en-3(beta)-ol
cholesterin
|-
| [http://en.wikipedia.org/wiki/Chemical_formula Molecular formula]
| C<sub>27</sub>H<sub>46</sub>O
|-
| [http://en.wikipedia.org/wiki/Chemical_file_format SMILES] 
| O[C@H](C4)CC[C@@]1(C)C4=CC[C@]2([H])[C@@]([H])1 CC[C@@]3(C)[C@]([H])2CC[C@@H]3[C@H](C)CCCC(C)C
|-
| [http://en.wikipedia.org/wiki/Molar_mass Molar mass]
| 386.65354g/mol
|-
| Appearance
| Soft, waxy yellow solid
|-
| [http://en.wikipedia.org/wiki/CAS_registry_number CAS number]
| 57-88-5, 474-77-1, 14868-17-8, 23820-70-4, 34026-89-6, 57759-45-2, 71869-93-7, 121155-47-3, 138456-89-0
|-
| ACX Number
| X1001660-1
|-
! {{chembox header}} | Properties
|-
| [http://en.wikipedia.org/wiki/Density Density] & [http://en.wikipedia.org/wiki/Phase_%28matter%29 phase]
| 1.067g/cm³ 
|-
| [http://en.wikipedia.org/wiki/Solubility Solubility in water]
| {{{Sol_Water}}} g/100 ml (25°C) 
|-



| [http://en.wikipedia.org/wiki/Melting_point Melting point]
| 148°C (421K) 
|-
| [http://en.wikipedia.org/wiki/Boiling_point Boiling point]
| 360°C (633K)
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Acidity] (p''K''<sub>a</sub>) 
| {{{pKa}}}
|-
| [http://en.wikipedia.org/wiki/Acid_dissociation_constant Basicity] (p''K''<sub>b</sub>) 
| {{{pKb}}}
|-
| [http://en.wikipedia.org/wiki/Specific_rotation Chiral rotation <nowiki>[α]</nowiki><sub>D</sub>] 
| {{{Rotation}}}°
|-
| [http://en.wikipedia.org/wiki/Viscosity Viscosity]
| {{{Viscosity}}} [[Poise|cP]] at 25°C 
|-
! {{chembox header}} | Structure
|-
| [http://en.wikipedia.org/wiki/Orbital_hybridisation Molecular shape] 
| {{{Mol_Shape}}} 
|-
| [http://en.wikipedia.org/wiki/Coordination_geometry Coordination<br />geometry] 
| {{{Coordination}}} 
|-
| [http://en.wikipedia.org/wiki/Crystal_structure Crystal structure] 
| {{{Crystal_Structure}}} 
|-
| [[Dipole#Molecular_dipoles|Dipole moment]]
| {{{DM}}} [[Debye|D]]
|-
! {{chembox header}} | Hazards 
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] 
|-
| Main [[Worker safety and health|hazard]]s
| {{{Hazards}}} 
|-
| [[NFPA 704]]
| {{{NFPA}}}
|-
| [[Flash point]]
| 250°C
|-
| [[Risk and Safety Statements|R/S statement]]
| [[List of R-phrases|R]]: {{{R-S}}} <br /> [[List of S-phrases|S]]: ?
|-
| [[RTECS]] number
| {{{RTECS}}}
|-
! {{chembox header}} | [[{{PAGENAME}} (data page)|Supplementary data page]]
|-
| [[{{PAGENAME}} (data page)#Structure and properties|Structure and<br />properties]]
| [http://en.wikipedia.org/wiki/Refractive_index ''n''], [http://en.wikipedia.org/wiki/Dielectric_constant ε<sub>r</sub>], etc.
|-
| [[{{PAGENAME}} (data page)#Thermodynamic properties|Thermodynamic<br />data]]
| Phase behaviour<br />Solid, liquid, gas
|-
| [[{{PAGENAME}} (data page)#Spectral data|Spectral data]]
| [[UV/VIS spectroscopy|UV]], [[Infrared spectroscopy|IR]], [[nuclear magnetic resonance spectroscopy|NMR]], [[Mass spectrometry|MS]]
|-
! {{chembox header}} | Related compounds
|-
| Other [[Ion|anion]]s 
| {{{Other_anion}}} 
|-
| Other [[Ion|cation]]s 
| {{{Ohter_cation}}} 
|-
| Related compounds

| {{{Relative_Compounds}}}
|-
| {{chembox header}} | <small>Except where noted otherwise, data are given for<br /> materials in their [[standard state|standard state (at 25 °C, 100 kPa)]]<br />[[wikipedia:Chemical infobox|Infobox disclaimer and references]]</small>
|-
|}
{{Chem-Data_Structure}}

==Cholesterol==
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HEADER NONAME 22-Oct-07 NONE 1
TITLE NONE 2
AUTHOR WWW daemon apache NONE 3
REVDAT 1 22-Oct-07 0 NONE 4
ATOM 1 O 0 7.862 -0.699 0.647 0.00 0.00 O+0
ATOM 2 C 0 6.594 -0.363 0.080 0.00 0.00 C+0
ATOM 3 H 0 6.745 0.236 -0.818 0.00 0.00 H+0
ATOM 4 C 0 5.777 0.439 1.098 0.00 0.00 C+0
ATOM 5 C 0 5.841 -1.644 -0.281 0.00 0.00 C+0
ATOM 6 C 0 4.523 -1.290 -0.973 0.00 0.00 C+0
ATOM 7 C 0 3.635 -0.504 -0.003 0.00 0.00 C+0
ATOM 8 C 0 3.301 -1.415 1.179 0.00 0.00 C+0
ATOM 9 C 0 4.393 0.680 0.518 0.00 0.00 C+0
ATOM 10 C 0 3.937 1.898 0.501 0.00 0.00 C+0
ATOM 11 C 0 2.590 2.259 -0.055 0.00 0.00 C+0
ATOM 12 C 0 1.661 1.044 0.046 0.00 0.00 C+0
ATOM 13 H 0 1.485 0.790 1.092 0.00 0.00 H+0
ATOM 14 C 0 2.334 -0.117 -0.686 0.00 0.00 C+0
ATOM 15 H 0 2.551 0.199 -1.707 0.00 0.00 H+0
ATOM 16 C 0 1.435 -1.349 -0.746 0.00 0.00 C+0
ATOM 17 C 0 0.057 -1.020 -1.342 0.00 0.00 C+0
ATOM 18 C 0 -0.550 0.075 -0.487 0.00 0.00 C+0
ATOM 19 C 0 -0.565 -0.360 0.980 0.00 0.00 C+0
ATOM 20 C 0 0.346 1.353 -0.647 0.00 0.00 C+0
ATOM 21 H 0 0.511 1.572 -1.702 0.00 0.00 H+0
ATOM 22 C 0 -0.535 2.433 -0.010 0.00 0.00 C+0
ATOM 23 C 0 -1.952 2.084 -0.543 0.00 0.00 C+0
ATOM 24 C 0 -1.936 0.566 -0.895 0.00 0.00 C+0
ATOM 25 H 0 -2.079 0.424 -1.966 0.00 0.00 H+0
ATOM 26 C 0 -3.026 -0.171 -0.114 0.00 0.00 C+0
ATOM 27 H 0 -2.865 -0.030 0.955 0.00 0.00 H+0
ATOM 28 C 0 -2.971 -1.664 -0.445 0.00 0.00 C+0
ATOM 29 C 0 -4.397 0.387 -0.501 0.00 0.00 C+0
ATOM 30 C 0 -5.476 -0.261 0.369 0.00 0.00 C+0
ATOM 31 C 0 -6.847 0.297 -0.019 0.00 0.00 C+0
ATOM 32 C 0 -7.926 -0.351 0.851 0.00 0.00 C+0
ATOM 33 C 0 -9.279 0.296 0.550 0.00 0.00 C+0
ATOM 34 C 0 -7.997 -1.848 0.545 0.00 0.00 C+0
ATOM 35 H 0 8.303 0.134 0.860 0.00 0.00 H+0
ATOM 36 H 0 5.693 -0.125 2.027 0.00 0.00 H+0
ATOM 37 H 0 6.266 1.394 1.290 0.00 0.00 H+0
ATOM 38 H 0 6.452 -2.247 -0.953 0.00 0.00 H+0
ATOM 39 H 0 5.633 -2.211 0.626 0.00 0.00 H+0
ATOM 40 H 0 4.727 -0.681 -1.854 0.00 0.00 H+0
ATOM 41 H 0 4.013 -2.205 -1.273 0.00 0.00 H+0
ATOM 42 H 0 4.206 -1.612 1.754 0.00 0.00 H+0
ATOM 43 H 0 2.564 -0.927 1.817 0.00 0.00 H+0
ATOM 44 H 0 2.894 -2.356 0.810 0.00 0.00 H+0
ATOM 45 H 0 4.555 2.686 0.907 0.00 0.00 H+0
ATOM 46 H 0 2.170 3.087 0.516 0.00 0.00 H+0
ATOM 47 H 0 2.694 2.551 -1.100 0.00 0.00 H+0
ATOM 48 H 0 1.915 -2.111 -1.359 0.00 0.00 H+0
ATOM 49 H 0 1.301 -1.740 0.263 0.00 0.00 H+0
ATOM 50 H 0 0.171 -0.670 -2.368 0.00 0.00 H+0
ATOM 51 H 0 -0.578 -1.905 -1.319 0.00 0.00 H+0
ATOM 52 H 0 0.456 -0.540 1.316 0.00 0.00 H+0
ATOM 53 H 0 -1.014 0.426 1.588 0.00 0.00 H+0
ATOM 54 H 0 -1.148 -1.276 1.082 0.00 0.00 H+0
ATOM 55 H 0 -0.505 2.363 1.078 0.00 0.00 H+0
ATOM 56 H 0 -0.231 3.425 -0.343 0.00 0.00 H+0
ATOM 57 H 0 -2.699 2.272 0.228 0.00 0.00 H+0
ATOM 58 H 0 -2.173 2.677 -1.431 0.00 0.00 H+0
ATOM 59 H 0 -3.131 -1.805 -1.513 0.00 0.00 H+0
ATOM 60 H 0 -1.994 -2.061 -0.168 0.00 0.00 H+0
ATOM 61 H 0 -3.747 -2.188 0.112 0.00 0.00 H+0
ATOM 62 H 0 -4.406 1.466 -0.349 0.00 0.00 H+0
ATOM 63 H 0 -4.595 0.167 -1.550 0.00 0.00 H+0
ATOM 64 H 0 -5.466 -1.340 0.216 0.00 0.00 H+0
ATOM 65 H 0 -5.277 -0.041 1.418 0.00 0.00 H+0
ATOM 66 H 0 -6.856 1.376 0.134 0.00 0.00 H+0
ATOM 67 H 0 -7.045 0.077 -1.068 0.00 0.00 H+0
ATOM 68 H 0 -7.679 -0.206 1.903 0.00 0.00 H+0
ATOM 69 H 0 -9.526 0.151 -0.502 0.00 0.00 H+0
ATOM 70 H 0 -10.048 -0.166 1.170 0.00 0.00 H+0
ATOM 71 H 0 -9.229 1.363 0.768 0.00 0.00 H+0
ATOM 72 H 0 -7.032 -2.309 0.759 0.00 0.00 H+0
ATOM 73 H 0 -8.765 -2.310 1.164 0.00 0.00 H+0
ATOM 74 H 0 -8.243 -1.993 -0.507 0.00 0.00 H+0
CONECT 1 2 35 0 0 NONE 79
CONECT 2 1 3 4 5 NONE 80
CONECT 4 2 9 36 37 NONE 81
CONECT 5 2 6 38 39 NONE 82
CONECT 6 5 7 40 41 NONE 83
CONECT 7 6 14 8 9 NONE 84
CONECT 8 7 42 43 44 NONE 85
CONECT 9 7 4 10 0 NONE 86
CONECT 10 9 11 45 0 NONE 87
CONECT 11 10 12 46 47 NONE 88
CONECT 12 11 20 13 14 NONE 89
CONECT 14 12 15 7 16 NONE 90
CONECT 16 14 17 48 49 NONE 91
CONECT 17 16 18 50 51 NONE 92
CONECT 18 17 24 19 20 NONE 93
CONECT 19 18 52 53 54 NONE 94
CONECT 20 18 21 12 22 NONE 95
CONECT 22 20 23 55 56 NONE 96
CONECT 23 22 24 57 58 NONE 97
CONECT 24 23 25 18 26 NONE 98
CONECT 26 24 27 28 29 NONE 99
CONECT 28 26 59 60 61 NONE 100
CONECT 29 26 30 62 63 NONE 101
CONECT 30 29 31 64 65 NONE 102
CONECT 31 30 32 66 67 NONE 103
CONECT 32 31 33 34 68 NONE 104
CONECT 33 32 69 70 71 NONE 105
CONECT 34 32 72 73 74 NONE 106
END NONE 107

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===Introduction===

Cholesterol is a '''lipid''' with a waxy, fatty texture that doesn’t dissolve in water. To be specific, cholesterol is a sub-set of lipids known as a '''steroid'''. It can be found naturally in the bloodstream and tissue of animals (especially the liver, spinal cord and the brain) where it makes up cell membranes; is used to make vitamin D, adrenal gland hormones and sex hormones: and carries out many other functions.
It must be transported between cells by carriers known as '''lipoproteins''' because it cannot dissolve in the blood. The soft, waxy texture of cholesterol means that too much cholesterol in the diet can result in '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – which can lead to heart attack.

{| border="1"
|-
|+ ''Crystals of cholesterol shown in a false colour scanning electron micrograph.''
![[Image:Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://www.scienceclarified.com/Ca-Ch/Cholesterol.html.JPG</sub>
|}

===Types of cholesterol===

There are 3 types of cholesterol:

#Cholesterol carried around in the blood by '''Low Density Lipoproteins (LDL)''' (also known as '''''“bad”''''' cholesterol) is the most common form of cholesterol in the blood. The body needs cholesterol to work properly and cells usually absorb it from the bloodstream as they need it. However, an excess of LDL cholesterol in the bloodstream can result in an accumulation of LDL cholesterol along with other substances on the walls of arteries. This can result in a condition called '''atherosclerosis''' in which the build up of cholesterol forms '''plaque''', a tough deposit that narrows the arteries. Blood flow can be blocked if a '''clot (thrombus)''' forms near to this plaque. If this blockage is near to heart muscle, a heart attack results. If it is near to any part of the brain, it leads to a stroke. Hence, high levels of LDL increase the risk of heart disease.
#The 2nd type of cholesterol is a genetic variation of LDLs known as '''Lp(a) cholesterol'''. High levels of Lp(a) cholesterol are believed to increase the risk of heart disease by leading to atherosclerosis prematurely, although the exact reason why is not known. It is believed that Lp(a) cholesterol may react with substances contained in the lesions in the artery walls, resulting in an accumulation of fatty deposits.
#Cholesterol carried by '''High Density Lipoproteins (HDL)''' (also known as '''''“good”''''' cholesterol) accounts for approximately 25-33% of the body’s cholesterol. HDL cholesterol tends to be transported away from arteries towards the liver, en route to being passed from the body. It has also been theorised that HDL cholesterol slows the growth of plaque by removing excess LDL cholesterol build up from the plaque. Contrary to LDL cholesterol, high levels of HDL cholesterol reduces the risk of heart disease and stroke.

===Where does cholesterol come from?===

Cholesterol comes from outside and inside the human body:

*'''''Inside''''' – The liver produces approximately 1000mg of cholesterol per day (it also helps to remove any excess cholesterol in the blood). This is approximately 80% of the cholesterol present in the body.

{| border="1"
|-
|+ ''Cholesterol is found naturally around the kidneys.''
![[Image:Cholesterol kidney.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://pharmalicensing.com/.../1128004281_433bfab90eaa8.JPG</sub>
|}

*'''''Outside''''' – Food from plants doesn’t contain cholesterol, however, food obtained from animals does.

In general, the body does not need any cholesterol from outside because it makes all the cholesterol that it needs within the body. If too much cholesterol is present in the bloodstream, '''hypercholesterolemia''' – the medical term for a build up of cholesterol in the bloodstream – can result, increasing the risk of heart disease. Saturated fatty acids and trans fats are the main causes of rising cholesterol levels in the blood. Cholesterol levels also tend to rise with age.

===How does the body make cholesterol?===

Cholesterol synthesis is a long, complex process. It involves several stages of the formation and subsequent conversion of intermediate compounds. This is a brief summary:
*Acetyl-CoA (CoA = coenzyme) and acetoacetyl-CoA undergo condensation to form '''Hydroxymethylglutaryl-coenzyme A (HMG-CoA)'''. The process is catalysed by HMG-CoA Synthase.
*HMG-CoA Reductase then catalyses the reduction of HMG-CoA to '''mevalonate'''. This is achieved by using NADPH to reduce the carboxyl group of hydroxymethylglutarate (HMG) (connected to the thiol of CoA via an ester linkage) to an aldehyde, followed by reduction to an alcohol. This reaction is the '''''rate determining step''''' of the whole cholesterol synthesis reaction and as such, is the reaction targeted by pharmaceutical drugs designed to control cholesterol levels in the body.
*The next stage involves two phosphate transfers from 2 ATP molecules to allow phosphorylation of the newly formed mevalonate molecule, giving a new '''pyrophosphate derivative'''. This derivative then undergoes ATP-dependent decarboxylation, with dehydration, catalysed by Pyrophosphomevolanate Decarboxylase, to form a compound called '''isopentenyl pyrophosphate'''. This newly formed compound is characterised as an isoprenoid because it is a derivative of isoprene (pictured).
*Isopentenyl pyrophosphate is then interconverted into '''dimethylallyl pyrophosphate''' by isopentenyl Pyrophosphate Isomerase, involving protonation and subsequent de-protonation. This means that there will be some molecules of isopentenyl pyrophosphate and some of dimethylallyl pyrophosphate present.
*Next, isopentenyl pyrophosphate undergoes a condensation reaction, catalysed by Prenyl Transferase, with the newly formed dimethylallyl pyrophosphate to yield a single '''geranyl pyrophosphate''' molecule. The geranyl pyrophosphate molecule then proceeds to undergo another condensation reaction with an isopentenyl pyrophosphate molecule, resulting in '''farnesyl pyrophosphate.'''
*The next stage involves synthesis of a molecule of '''squalene''', made by condensing 2 molecules of farnesyl pyrophosphate together. This condensation reaction involves reduction of NADPH and is catalysed by the catalyst Squalene Synthase.
*Squalene is oxidised to '''2,3-oxidosqualene''' (an epoxide), with the help of Squalene epoxidase (catalyst), NADPH (reductant) and O2 (oxidant, 2 molecules needed).
*Protonation of 2,3-oxidosqualene triggers a sequence of electron shifts, catalysed by Squalene Oxidocyclase, resulting in '''''cyclization'''''. This leads to the generation of the sterol '''lanosterol'''.
*The final step in cholesterol synthesis involves 19 sequential reactions, catalysed by enzymes found in the endoplasmic reticulum membranes, which convert lanosterol to the final '''cholesterol''' molecule. [http://www.jce.divched.org/Journal/Issues/2002/Mar/PlusSub/V79N03/p377.pdf Diagrams and details of these reactions]

The full synthesis, as well as diagrams that make the above description clearer and easier to understand, can be found [http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm here]

===Lowering your blood cholesterol levels===

Eating more fruits and vegetables can help, as these foods do not contain any cholesterol.

Any form of physical activity can help to reduce cholesterol levels by increasing HDL cholesterol and hence lower the risk of heart disease.
HDL cholesterol levels can also be increased through moderate drinking of alcohol – although drinking '''''too''''' much can result in dangers which outweigh the benefits.

Unsurprisingly, smoking has the opposite and undesirable effect of raising blood cholesterol levels by lowering HDL cholesterol levels and the secondary effect of causing your blood to clot more readily.

===Spectra===

{| border="1"
|-
|+ ''Mass Spectrum of Cholesterol.''
![[Image:IR Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=200#Mass-Spec</sub>
|}
|-
{| border="1"
|-
|+ ''IR spectrum of Cholesterol (KBr solution).''
![[Image:Mass spec Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC</sub>
|}
|-
{| border="1"
|-
|+ ''UV Spectrum of Cholesterol.''
![[Image:UV Cholesterol.jpg|250px|{{Cholesterol}}]]
|-
!<sub>http://webbook.nist.gov/cgi/cbook.cgi?ID=C57885&Units=SI&Mask=400#UV-Vis-Spec</sub>
|}

==References==

#Journal; Barton,D.H.R. et al.; JCPRB4; J. Chem. Soc. Perkin Trans. 1; EN; 1973; 599-603.
#Journal; Freire; Ribas; ANQUBU; An. Quim.; 71; 1975; 418,421.
#Journal; Vochten; Joos; JCPBAN; J. Chim. Phys. Phys. Chim. Biol.; 67; 1970; 1372,1375.
#Journal; Smith; Deavenport; JOMRA4; J. Magn. Reson.; 6; 1972; 257.
#Journal; Kasuga, Kazuyuki; Hatakeyama, Hyoe; Hatakeyama, Tatsuko; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 1-14.
#Journal; Adams, Nathan W.; Bradshaw, Jerald S.; Bayona, Jose-Maria; Markides, Karin E.; Lee, Milton L.; MCLCA5; Mol. Cryst. Liq. Cryst.; EN; 147; 1987; 43-60.
#http://www.americanheart.org/presenter.jhtml?identifier=4488
#http://www.nlm.nih.gov/medlineplus/cholesterol.html
#www.scienceclarified.com/Ca-Ch/Cholesterol.html
#http://heart.health.ivillage.com/cholesterol/cholesterol.cfm
#http://chemfinder.cambridgesoft.com/result.asp
#http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5997
#http://pharmalicensing.com/articles/disp/1128004281_433bfab90eaa8
#http://www.rpi.edu/dept/bcbp/molbiochem/MBWeb/mb2/part1/cholesterol.htm

File:UV Cholesterol.jpg

2007-10-29T14:19:58Z

Ikm06:

File:Mass spec Cholesterol.jpg

2007-10-29T14:19:47Z

Ikm06: