Cholesterol e sebelisoa e le mokoti oa mafura a nang le mafura a polyunsaturated.

E eketsa ho se lekane ha molek'hule. Ts'ebetso ena e etsahala ka ntle le ka mokhoa o makatsang; e lula e etselitsoe ho tlosa limolek'hule tsa cholesterol mohahong oa lipid / metsi o kenang ka har'a karolo ea lipoprotein. Ka tsela ena, ho tsamaisoa kapa ho kenngoa hoa cholesterol ho etsahala.

Extracellular cholesterol ester e qoelitsoe ke enzyme lecithin cholesterol acetyltransferase (LHAT).

Lecithin + Cholesterol Lysolecin + Cholesterol

Linoleic acid e tsamaisoa haholo-holo. Ketsahalo ea enzymatic ea LHAT e amana haholo le HDL. Mothetsi oa LHAT ke moo-A-I. Karolo ea cholesterol e bakiloeng ke karabelo e qoelisoa HDL. Maemong ana, khoholeho ea k'holeseterole ea mahala e holim 'a HDL e ea fokotsoa' me ka hona, bokaholimo bo lokiselitsoe ho fumana karolo e ncha ea cholesterol ea mahala, eo HDL e khonang ho e tlosa holim'a membrane ea plasma ea lisele, ho kenyelletsa lisele tse khubelu tsa mali. Kahoo, HDL hammoho le LHAT e sebetsa e le mofuta oa "sekoti" bakeng sa cholesterol.

Ho tloha ho HDL cholesterol esters e fetisetsoa VLDL, 'me ho tloha morao e fetisetsoa ho LDL. LDL e entsoe ka har'a sebete 'me e hatelloa moo. HDL e tlisa k'holeseterole ka sebopeho sa esters ho sebete, 'me e tlosoa sebeteng e le li-acid acid. Ho bakuli ba nang le bothata bo futsitseng ba LHAT ka plasma, ho na le cholesterol e ngata ea mahala. Ho bakuli ba nang le tšenyo ea sebete, e le molao, ts'ebetso e tlase ea LHAT le boemo bo phahameng ba k'holeseterole ea mali e fumanoa.

Ka hona, HDL le LHAT li emela sistimi e le 'ngoe ea ho tsamaisa k'holeseterole ho tsoa liseleng tsa plasma tsa lisele tsa litho tse fapaneng ka sebopeho sa esters ea eona ho sebete.

Cholesterol ea Intracellular e hakanyetsoa ho karabelo e anngoeng ke acyl-CoA cholesterol acetyl transase (AChAT).

Acyl-CoA + Cholesterol Cholesterol + HSKoA

Ntlafatso ea membrane e nang le cholesterol e kenya letsoho ho AHAT.

Ka lebaka leo, ho potlakisa tlhahiso ea cholesterol kapa synthesis ho tsamaisana le ho potlakisa matla a esterization ea eona. Ho batho, linoleic acid hangata e kenella ho esteration ea cholesterol.

Tekanyo ea k'holeseterole e ka seleng e lokela ho nkoa e le karabelo e tsamaeang le ho bokelloa ha steroid ho eona. Li-esters tsa cholesterol ka har'a sebete ka mor'a hore ho sebelisoe hydrolysis ho kopanya li-acid acid, 'me ka har'a litšoelesa tsa adrenal, lihormone tsa steroid.

T.O. LHAT e notlolla li-membrase tsa plasma tse tsoang k'holeseteroleng, 'me AHAT e notlolla tse kenang kahare. Li-enzyme tsena ha li tlose k'holeseterole liseleng tsa 'mele, empa li e fetisetsa sebopeho se seng ho ea ho se seng, ka hona, karolo ea li-encyme tsa esteration le hydrolysis tsa li-cholesterol tsa nts'etsopele ea ts'ebetso ea methapo ea methapo ha ea lokela ho feteletsoa.

Tloaelo e akaretsang

• li thehiloe ka sebetede novoka plasma mali nakong ea ho phunyeha ha li-chylomicrons, palo e itseng leboteng mala,
• hoo e ka bang halofo ea likaroloana ke liprotheine, karolo e 'ngoe ea kotara e le phospholipids, tse ling kaofela ke cholesterol le TAG (50% protheine, 25% PL, 7% TAG, 13% cholesterol esters, 5% free cholesterol),
• apothecine e ka sehloohong ke apo A1na leEE le apoCII.

1. Tsamaiso ea k'holeseterole ea mahala ho tsoa lithong ho ea isibeteng.
2. Phospholipids ea HDL ke mohloli oa acid ea polyenoic bakeng sa motsoako oa phospholipids ea cellular le eicosanoids.

Cholesterol biosynthesis

Ka 1769, Pouletier de la Sal o ile a amohela ho tsoa maballong ntho e tšoeu e tšoeu ("mafura"), e neng e na le thepa ea mafura. Ka sebopeho sa eona se hloekileng, k'holeseterole e ile ea qheleloa ka thoko ke k'hemistri, setho sa Kopano ea naha le Letona la Thuto Antoine Fourcroix ka 1789. Ka 1815, Michel Chevreul, eo le eena a qheletseng kharetene ena, o ile a e bitsa cholesterol ("khohole" - bile, "stereo" - e tiileng). Ka 1859, Marseille Berthelot o ile a paka hore cholesterol ke ea sehlopha sa li-alcohols, kamora moo Fora e ile ea reha cholesterol ho "cholesterol". Lipuong tse 'maloa (Serussia, Sejeremane, Sehungary le tse ling), lebitso la khale - k'holeseterole - le bolokiloe.

Edit edit ea Cholesterol biosynthesis |