Musamman tsarin da kuma aiki na cell membranes

A shekarar 1972, ya aka sa a gaba da ka'idar cewa partially permeable membrane kewaye da salula, kuma ya aikata wani yawan m ayyuka, da kuma tsarin da kuma aiki na cell membranes ne muhimmi al'amurran da suka shafi game da dace aiki na duk Kwayoyin a cikin jiki. Cell ka'idar zama tartsatsi a cikin 17th karni, tare da sabuwar dabara na da hange. An koya cewa shuka da dabbobi kyallen takarda an hada da Kwayoyin, amma saboda da low ƙuduri na na'ura ba shi yiwuwa a ga wani cikas a kusa da dabba Kwayoyin. A cikin karni na 20th, da sinadaran yanayin da membrane aka bincika a more daki-daki, an gano cewa ta da asali ne lipids.

Tsari da kuma aiki na cell membranes

A jikin tantanin na kewaye da cytoplasm rayuwa Kwayoyin, jiki raba kwayuka aka gyara daga waje muhalli. Fungi, kwayoyin cuta da kuma shuke-shuke ma da cell ganuwar da kare da kuma hana wucewa da manyan kwayoyin. Cell membranes kuma taka rawa a cikin samuwar na cytoskeleton da aka haɗe zuwa extracellular matrix sauran m barbashi. Wannan shi ne zama dole domin ya kiyaye su tare da nunawa tsokoki da kuma gabobin. Features na jikin tantanin tsarin hada permeability. Babban aiki shi ne ka kare. A membrane kunshi wani phospholipid Layer tare da saka sunadaran. Wannan bangare ne da hannu a matakai kamar cell mannewa, ion watsin da sigina tsarin da hidima a matsayin hawa surface ga dama extracellular Tsarin, ciki har da bango glycocalyx da ciki cytoskeleton. A membrane kuma rike da m na Kwayoyin, aiki a matsayin zabe tace. Shi ne selectively permeable zuwa ions da kwayoyin kwayoyin da kuma iko da motsi na da barbashi.

Halittu sunadaran shafe jikin tantanin

1. m yadawa: wasu abubuwa (kananan kwayoyin, ions) kamar carbon dioxide (CO2) da kuma oxygen (O2), zai shiga cikin jini membrane ta yadawa. A casing ayyukan matsayin wani shãmaki a wasu kwayoyin da ions, su za a iya mayar da hankali a garesu.

2. A transmembrane gina jiki tashoshi da kuma transporters: gina jiki kamar glucose ko amino acid, ya kamata a sami a cikin keji, da kuma wasu na rayuwa kayayyakin kamata bar shi.

3. endocytosis - ne tsari da wanda kwayoyin suna tunawa. kadan nakasawa (intussusception) an halitta a cikin jini membrane, cikinsa da abu zuwa a hawa, aka haɗiye shi. Wannan na bukatar makamashi, kuma ta haka ne, shi ne wani nau'i na aiki kai.

4. Exocytosis: auku a daban-daban Kwayoyin cire undigested abubuwa sharan kawo endocytosis zuwa asirce abubuwa, kamar hormones, enzymes, da kuma kai kayan duk hanyar da ta cikin cell shãmaki.

kwayoyin tsarin

Cell membrane - mai nazarin halittu harsashi kunsha da gaske na phospholipid da kuma raba da abun ciki na duk Kwayoyin daga yanayi. Kan aiwatar da samuwar auku spontaneously karkashin al'ada yanayi. Don gane da wannan tsari da kuma daidai bayyana tsarin da kuma aiki na cell membranes, kazalika da kaddarorin zama dole domin tantance yanayin da phospholipid tsarin, wanda yake shi ne halayyar da tsarin rabuwa. Lokacin da phospholipids a cikin ruwa-ruwa yanayi na cytoplasm isa wani m taro, suna hade a cikin micelles, wanda sun fi karko a wani ruwa-ruwa yanayi.

membrane Properties

• Stability. Wannan yana nufin cewa bayan samuwar auka daga cikin membrane ne mai wuya.
• Ƙarfi. A sia ambulan robust isa ya hana nassi na iyakacin duniya abubuwa, kafa ta cikin iyakar ba zai iya wuce matsayin solutes (ions, glucose, amino acid), da kuma mai yawa ya fi girma kwayoyin (proteins).
• A tsauri yanayi. Wannan watakila mafi muhimmanci dukiya, idan muka yi la'akari da tsarin da cell. A jikin tantanin iya fallasa su daban-daban damuwa, kuma za a iya folded tanƙwara, kuma ba karya. A karkashin yanayi na musamman, kamar dauke da tsatson vesicles dake tasowa ko shi za a iya karya ba, amma kawai na dan lokaci. A dakin da zazzabi, da sia aka gyara su ne a akai, m motsi, kafa barga ruwa iyaka.

Bewafa mosaic model

Da yake jawabi game da sifa da aiki na cell membranes, yana da muhimmanci a lura da cewa a yau gabatar da membrane a matsayin m mosaic model, shi da aka yi nazari da masana kimiyya a shekara ta 1972 da Singer da Nicholson. Ka'idarsu nuna uku babban fasali na tsarin da membrane. Na game membrane sunadaran da taimako zuwa ga mosaic juna domin membrane, kuma suna iya kaikaice motsi a cikin jirgin sama saboda da maras tabbas yanayi na sia kungiyar. Transmembrane sunadarai ne ma yiwuwar mobile. An muhimmanci siffa daga cikin membrane tsari ne ta jeri na bangaren. Mene ne tsarin da cell? A jikin tantanin, tsakiya, da furotin da kuma sauransu. Cell ne muhimman hakkokin naúrar na rayuwa, da kuma duk kwayoyin kunshi daya ko mahara Kwayoyin, kowanne daga abin da na halitta da shamaki da ya raba shi daga yanayi. Wannan m iyaka da cell kuma ake kira jini membrane. Ya kunshi hudu daban-daban na kwayoyin: phospholipids, cholesterol, sunadaran da carbohydrates. Bewafa mosaic model bayyana tsarin da jikin tantanin kamar haka: m kuma na roba, da daidaito yayi kama da kayan lambu mai, don haka da cewa duk da mutum kwayoyin kawai taso kan ruwa a cikin wani ruwa matsakaici, kuma suna iya motsawa laterally cikin wannan harsashi. Mosaic wakiltar wani abu da qunshi yawa sassa daban daban. A cikin jini membrane shi da aka gabatar phospholipids, cholesterol kwayoyin, sunadarai, kuma carbohydrates.

phospholipids

Phospholipids dokoki da asali tsarin da jikin tantanin. Wadannan kwayoyin suna da biyu daban-daban karshen: wani shugaban da wutsiya. The shugaban karshen qunshi wani phosphate kungiyar, kuma shi ne hydrophilic. Wannan yana nufin cewa shi ne janyo hankalin ruwa kwayoyin. A wutsiya kunshi hydrogen da carbon atoms, da ake kira m acid sarƙoƙi. Wadannan sarƙoƙi ne hydrophobic, ba su son zuwa Mix da ruwa kwayoyin. Wannan tsari ne kama da abin da ya faru a lokacin da ka zuba man a cikin ruwa, ma'ana ba narke a cikin ta. Features na jikin tantanin tsarin alaka da ake kira sia bilayer, wanda ya kunshi phospholipids. Hydrophilic phosphate shugabannin suna da yaushe armashi, inda akwai ruwa a cikin nau'i na kwayuka da extracellular ruwa. A hydrophobic wutsiyoyi na phospholipids a cikin membrane da ake shirya a irin wannan hanyar da rike da su daga ruwa.

Cholesterol, sunadaran da carbohydrates

Ji da kalmar "cholesterol", mutane yawanci zaton cewa shi ne mafi sharri. Amma a gaskiya, cholesterol ne wani muhimmin bangaren da cell membranes. Its kwayoyin kunshi hudu zobba na hydrogen da carbon atoms. Su hydrophobic da ake samu a cikin hydrophobic wutsiyoyi, a cikin lipid bi-Layer. Su duk da muhimmancin shi ne don kula da daidaito, da suka ƙarfafa membrane, hana mahada. cholesterol kwayoyin ma rike da phospholipid wutsiyoyi daga shigowa lamba kuma solidifies. Wannan na tabbatar da fluidity da kuma sassauci. Matattarar sunadaran gina jiki da aiki na enzymes don hanzarta sinadaran halayen, aiki a matsayin rabe ga takamaiman kwayoyin, ko da abubuwa hawa ta cikin jikin tantanin.

Carbohydrates, ko sugars, an samu kawai a kan extracellular gefen jikin tantanin. Tare da suke samar da glycocalyx. Yana bayar da cushioning da kuma kariya na jini membrane. Bisa ga Tsarin da iri carbohydrates a cikin jiki glycocalyx na sel iya gane da kuma sanin ko suna bukatar zama a can, ko ba.

membrane sunadaran

A tsarin da cell membrane na dabba cell ba abu mai yiwuwa ba tare da irin wannan gagarumin bangaren na gina jiki. Duk da wannan, su ne da yawa na baya zuwa girman da sauran muhimmin bangaren - lipids. Akwai uku na asali iri membrane sunadaran.

• Na game. Suna gaba daya rufe da bi-Layer, da cytoplasm da extracellular matsakaici. Sun gudanar da wani kai da sigina aiki.
• Gefe. Sunadaran a haɗe zuwa membrane ta yin amfani da electrostatic, ko hydrogen shaidu a cikin su cytoplasmic ko extracellular saman. Sun shiga da gaske a matsayin fastening nufi ga na game da sunadarai.
• Transmembrane. Sun yi aiki enzymatic da sigina ayyuka, kuma modulate ainihin tsarin da sia bi-Layer membrane.

Ayyuka na nazarin halittu membranes

A hydrophobic sakamako wanda na shugabancin hali na hydrocarbon a ruwa, iko Tsarin kafa ta membrane lipids, kuma matattarar sunadaran. Mutane da yawa membrane Properties ni'imtar da dako sia bi-yadudduka, forming wani tushe tsarin domin duk nazarin halittu membranes. Na game membrane sunadarai partially a ɓõye, a cikin lipid bi-Layer. Transmembrane sunadaran da musamman kungiyar na amino acid a cikin su primary jerin.

Gefe membrane sunadaran suna kama da narkewa, amma su ma da nasaba da membranes. Musamman cell membranes ne na musamman cell aiki. Kamar yadda tsarin da kuma ayyuka na cell membranes da wani tasiri a jiki? A yadda za a yi nazarin halittu membranes dogara a kan tabbatar da ayyuka na dukan kwayoyin. Daga kwayuka wasu gabbansa, extracellular da cell-cell interactions, membrane Tsarin ne wajibi ga kungiyar da kuma kwaikwayon na nazarin halittu ayyuka. Mutane da yawa daga cikin tsarin da kuma aikin fasali su ne kowa da kwayoyin cuta, eukaryotic Kwayoyin da ya wajaba a ƙwayoyin cuta. All nazarin halittu membranes gina a kan sia bi-Layer, wanda ya haddasa kasancewar wani adadin na kowa halaye. Matattarar sunadaran gina jiki da dama musamman ayyuka.

• Controls. A jini membranes na sel ayyana iyakokin cell hulda da yanayi.
• Sufuri. Kwayuka membrane cell kasu kashi da dama aikin tubalan da daban-daban ciki abun da ke ciki, wanda kowannensu yana goyan bayan da zama dole kai aiki a tare da tare da lura da permeability.
• Signal transduction. membrane Fusion samar da wani inji for kwayuka vesicular gargadi da hana dukan ƙwayoyin cuta da yardar kaina shiga cikin cell.

Darajar da karshe

A tsarin da m membrane na cell rinjayar da dukan jiki. Yana taka muhimmiyar rawa a kare mutunci, da barin shigar azzakari cikin farji na kawai zabi kayan. Shi ne kuma mai kyau tushe don kayyade da cytoskeleton da cell bango, wanda taimaka a rike cell siffar. Lipids dokoki game da 50% na da taro na membrane na mafi Kwayoyin, ko da yake wannan dabam dangane da irin membrane. A tsarin da m jikin tantanin na dabbobi masu shayarwa ne mafi wuya, akwai dauke hudu na asali phospholipid. An muhimmanci dũkiyar sia bi-yadudduka shi ne cewa su nuna hali kamar yadda biyu-girma ruwa a cikin abin da mutum kwayoyin su kyauta juya da kuma motsa a kaikaice kwatance. Wannan fluidity - wannan shi ne wani muhimmin dukiya daga cikin membrane, wanda aka ƙaddara dangane da zafin jiki da kuma sia abun da ke ciki. Saboda hydrocarbon zobe tsarin cholesterol taka wata rawa a kayyade da membrane fluidity. Zababben permeability na nazarin halittu membranes zuwa kananan kwayoyin damar da cell wajen saka idanu da kuma kula da ciki tsari.

Idan akai la'akari da tsarin da Kwayoyin (cell membrane, tsakiya, da sauransu), za mu iya cewa da kwayoyin - shi ne kai-gudãnar tsarin cewa unaided bã zai iya cũtar da kanka kuma za ko da yaushe duba hanyoyin da za a mayar da kare dace aiki na kowane cell.