A na-eji cholesterol eme ihe dika polyunsaturated fatty acids.

Na-abawanye ihe na-adịghị polarity nke molekul. Usoro a na - eme ma n'èzí ma na intracellularly, a na - ezube ya mgbe niile iwepu ụmụ irighiri mmiri cholesterol site na ihe omimi dị n'ime mmiri nke lipoprotein. N'ụzọ dị otu a, ebugharị ma ọ bụ rụọ ọrụ cholesterol na - apụta.

Esemokwu extracellular cholesterol bụ nke enzyme lecithin cholesterol acetyltransferase (LHAT) na-ewere.

Lecithin + cholesterol Lysolecin + cholesterol

Linoleic acid na-ebugharị n'ụzọ kachasị. Ọrụ enzymatic nke LHAT bụ ejikọtara ya na HDL. Onye na-eme ka LHAT rụọ ọrụ bụ apo-A-I. Chostererol ester nke mmeghachi omume na-emikpu na HDL. N'okwu a, a na-ebelata mkpụkọ cholesterol dị elu nke HDL ma si otú a kwadebere elu maka nnata nke cholesterol ọhụrụ, nke HDL nwere ike iwepu elu plasma akpụkpọ ahụ nke sel, gụnyere sel ọbara. Ya mere, HDL yana oru LHAT dika “onya” nke cholesterol.

Site na HDL cholesterol esters na-agafere na VLDL, site na nke ikpeazụ gaa na LDL. A na-eke LDL n'ime imeju na catabolized ebe ahụ. HDL na-ebute cholesterol n'ụdị esters na imeju, ma wepụ ya na imeju dịka bile acid. N'ime ndị ọrịa nwere mmerụ akụrụngwa nke LHAT na plasma, enwere ọtụtụ cholesterol n'efu. N'ime ndị ọrịa nwere mmebi imeju, dịka iwu, LHAT dị ala na ọkwa cholesterol dị elu na plasma ọbara.

Ya mere, HDL na LHAT na-anọchite anya otu usoro maka ebufe cholesterol site na membranes plasma nke mkpụrụ ndụ nke akụkụ dị iche iche n'ụdị nke esters ya na imeju.

Achọtara cholesterol intracellular na mmeghachi omume nke transperase acyl-CoA cholesterol acetyl (AChAT).

Acyl-CoA + Cholesterol Cholesterol + HSKoA

Ọkpụkpụ membranes na cholesterol na-eme ka AHAT rụọ ọrụ.

N'ihi nke a, mmụba nke mmepụta cholesterol ma ọ bụ njikọta na-esonyere osooso nke mbu ya. N'ime mmadụ, linoleic acid na-abụkarị ihe metụtara cholesterol.

Ekwesịrị ka iwere cholesterol dị na sel dịka mmeghachi omume yana nchịkọta steroid n'ime ya. A na - eji cholesterol esters na imeju mgbe a na - ejikọ hydrolysis synthesize bile acids, na ụbụrụ adrenal, homonụ steroid.

T.O. LHAT na-ebupata membranes plasma site na cholesterol, na AHAT na-ebugharị ndị nwere intracellular. Enzymes ndị a anaghị ewepụ cholesterol n'ime sel nke anụ ahụ, mana bufee ya na otu ụdị gaa na nke ọzọ; yabụ ọrụ ensterọsa na enzymes nke enzymes nke cholesterol nke dị na mmepe nke usoro pathologies ekwesighi ikwubiga ya ókè.

Omume General

• etinyere n’ime imejude novon'ime plasma ọbara n'oge ọgbụgba nke chylomicrons, ego ole na mgbidi ahụ eriri afọ,
• ihe dị ka ọkara nke ahụ bụ protein, otu ụzọ n'ụzọ anọ nke phospholipids, ihe ndị ọzọ bụ cholesterol na TAG (protein 50%, 25% PL, 7% TAG, 13% cholesterol esters, cholesterol 5%),
• isi apothecine bu apo A1nwere apoE na apoCII.

1. Transportbufe cholesterol n'efu site na anụ ahụ gaa na imeju.
2. Phospholipids HDL bụ isi iyi nke polyenoic acid maka njikọ nke cellular phospholipids na eicosanoids.

Cholesterol biosynthesis

N'afọ 1769, Pouletier de la Sal natara nnụnụ ọcha (nnukwu ") nke nwere abụba buru ibu. N’usoro dị ọcha, kọmịsis kewapụrụ ya, onye so na Mgbakọ Mba ahụ na Minista Mmụta Antoine Fourcroix na 1789. N’afọ 1815, Michel Chevreul, onye kewapụrụ ogige a, kpọrọ ya cholesterol (“chole” - bile, “stereo” - solid). Na 1859, Marseille Berthelot gosipụtara na cholesterol bụ nke ndị ahoụrụma, mgbe nke ahụ gasịrị, onye France kpọgharịrị kọlesterol ka ọ bụrụ “cholesterol”. N'ọtụtụ asụsụ (Russian, German, Hungarian na ndị ọzọ), echekwara aha ochie - cholesterol.

Cholesterol biosynthesis edit |