A surface naúrar cell: sifa da aiki

A surface naúrar cell ne a duniya subsystem. Yana da kayyade iyaka tsakanin waje yanayi da kuma cytoplasm. PAK samar da tsari na hulda. Mun gaba la'akari da peculiarities na tsarin-aikin kungiyar na cell surface na'ura.

aka gyara

Gane da wadannan aka gyara daga cikin na'ura surface na eukaryotic Kwayoyin: da jini membrane, nadmembranny da submemranny gidaje. A farko wakilci a cikin nau'i na rufaffiyar siffar zobe kashi. Plasmolemma dauke da kashin baya na farfajiya na cell naúrar. Nadmembranny hadaddun (shi ne kuma ya kira glycocalyx) - shi ne wani m memba zubar a kan jini membrane. Ya kunshi daban-daban aka gyara. A musamman, wadannan sun hada da:

1. A carbohydrate rabo daga glycoproteins da glycolipids.
2. A membrane na gefe sunadaran.
3. Specific carbohydrates.
4. Poluintegralnye da kuma na game da sunadarai.

Submembranny hadaddun aka located a plasmolemma. Ya kunshi zama ruwan dare support-contractile tsarin da kuma na gefe hyaloplasm.

Abubuwa submembrannogo hadaddun

Idan akai la'akari da tsarin da na'ura na cell surface, yana daukan wani raba look at da na gefe hyaloplasm. Shi ne na musamman cytoplasmic rabo da kuma located sama plasmolemma. Gefe hyaloplasm wakilta a matsayin mai matuƙar bambancin da iri-irin ruwa abu. Ya ƙunshi wani iri-iri na high da kuma low kwayoyin nauyi aka gyara a cikin bayani. A gaskiya, shi ne mai microenvironment a cikin abin da kwarara-takamaiman da kuma janar tafiyar matakai na rayuwa. Gefe hyaloplasm samar da jam'i na surface ayyuka na na'ura.

Musculoskeletal contractile tsarin

An located in da na gefe hyaloplasm. The goyon-contractile tsarin release:

1. Microfibrils.
2. Kwarangwal fibrils (matsakaici filament).
3. Microtubules.

Microfibrils ne filamentous Tsarin. Kwarangwal fibrils an kafa ta Polymerization da dama sunadarai na gina jiki. Da lambar kuma tsawon ke kula da musamman shirye-shirye. Lokacin da suka canza anomalies bayyana salon salula ayyuka. Mafi nĩsa daga plasmalemma microtubules. Su ganuwar suna kafa tubulins sunadaran.

Tsarin da kuma aiki na cell surface naúrar

Metabolism da aka yi da ciwon kai sunadaran. A tsarin da surface naúrar cell sa da dabba ba a kanta na mahadi da hanyoyin da dama. A musamman, wadannan iri kai:

1. Simple yadawa.
2. M kai.
3. Active motsi.
4. Cytosis (musayar membrane a cikin kunshin).

Bugu da kari a kai, ya bayyana surface siffofin irin na'ura na cell, kamar:

1. Shamaki (rarraba).
2. Tsoka mai amsa sigina.
3. Identification.
4. Aiki cell motsi ta hanyar ilimi Falsafa, pseudo- da lamellipodia.

free motsi

Simple yadawa ta hanyar da surface naúrar cell ne da za'ayi na musamman a gaban a garesu daga cikin membrane lantarki dan tudu. Its size kayyade gudu da kuma shugabanci na motsi. Bilipidny Layer iya tsallake wani irin kwayoyin hydrophobic. Duk da haka, mafi ilimin aiki abubuwa ne hydrophilic. Haka kuma, su free motsi wuya.

m kai

Wannan irin fili motsi kuma ake kira Facilitated yadawa. Haka kuma an za'ayi ta hanyar da surface naúrar Kwayoyin a gaban wani dan tudu da ba tare da ATP amfani. M kai da sauri fiye da free. A kan aiwatar da kara bambanci a maida hankali dan tudu zo da wani nufi a cikin abin da dabba ba a kanta gudun zama m.

dako

Kai ta hanyar da surface na'ura na cell da aka bayar da musamman kwayoyin. Tare da wadannan vectors da wani taro dan tudu ne manyan kwayoyin da hydrophilic irin (amino acid, musamman). Surface na'ura eukaryotic Kwayoyin hada vectors ga wani iri-iri m ions: K +, Na +, Ca +, Cl-, HCO3-. Wadannan musamman kwayoyin suna halin high selectivity zuwa hawa abubuwa. Bugu da kari, wani muhimmin alama ne ga mai girma tafiya gudun. Yana iya isa 104 ko fiye da kwayoyin da na biyu.

aiki kai

An halin motsi da abubuwa da da dan tudu. Kwayoyin suna hawa daga wani yankin na low taro a rabo mafi girma. Irin wannan yunkuri na bukatar wani kudin na ATP. Don yi aiki kai a cikin tsarin da surface na dabba cell na'ura hada da takamaiman vectors. Suna da ake kira "farashinsa" ko "farashinsa". Mutane da yawa na wadannan vectors bambanta ATPase aiki. Wannan yana nufin cewa sun sami damar karya saukar adenosine triphosphate da kuma cire makamashi domin gudanar da ayyukanta. Active kai sa halittar ion gradients.

cytosis

Wannan hanya da ake amfani da su matsa barbashi daban-daban abubuwa ko ya fi girma kwayoyin. A lokacin cytosis hawa kashi ne kewaye da wata matattarar vesicle. Idan motsi ne a cikin keji, to, shi ne ake kira endocytosis. Haka kuma, gaban shugabanci da aka kira exocytosis. A wasu Kwayoyin da abubuwa ratsa. Wannan irin kai ne ake kira transcytosis ko diatsiozom.

cytolemma

A tsarin da cell surface na'ura hada da wani jini membrane kafa yafi lipids da sunadarai a cikin wani rabo na game da 1: 1. A farko "Sandwich model" na kashi da aka samarwa a 1935 A daidai da ka'idar, tushen plasmolemma kafa sia kwayoyin shirya a biyu yadudduka (Layer bilipidny). Suka juya suka wutsiyoyi (hydrophobic yankuna) zuwa juna, da kuma waje, kuma a ciki - da hydrophilic kawunansu. Wadannan saman mai rufi da wani Layer bilipidnogo sunadarai na gina jiki. Wannan samfurin da aka tabbatar a cikin 50s maras ɗa'a karni ultrastructural nazarin yin amfani da na'urar hange. An musamman samu cewa surface naúrar qunshi wani uku-Layer dabba jikin tantanin. Its kauri ne 7.5-11 nm. Shi ne yanzu talakawan haske da duhu biyu na gefe Layer. A farko yayi dace da hydrophobic yankin na sia kwayoyin. Dark rabo bi da bi, wakiltar da m surface yadudduka da furotin da kuma hydrophilic kai.

sauran theories

A iri-iri na electron-microscopic binciken, gudanar a cikin marigayi 50 ta - farkon 60-ies. Sun nuna wa universality na kungiyar na uku Layer membrane. Wannan aka nuna a cikin ka'idar J. Robertson. A halin yanzu, da ƙarshen 60s. Na tara mai yawa facts cewa ba a bayyana cikin sharuddan data kasance "sanwic model". Wannan ya ba impetus zuwa cin gaban sabon makircinsu, wanda hada da model dangane gaban hydrophobic-hydrophilic m gina jiki da kuma sia kwayoyin. Daga cikin daya daga cikinsu ya ka'idar "lipoprotein kilishi." A daidai da shi, kunsha na membrane sunadarai ba iri biyu: na game da gefe. Recent daure da electrostatic interactions da iyakacin duniya shugabannin a kan sia kwayoyin. Duk da haka, da suka taba samar da wata m Layer. A muhimmiyar rawa a cikin samuwar membrane ne da mulkin globular sunadaran. Suna nutsa cikin zurfin shi kuma jera ake magana poluintegralnymi. Motsi wadannan sunadarai ne da za'ayi a cikin ruwa lokaci na sia. Wannan na tabbatar da lability, da kuma aiwatar da dukan membrane tsarin. A halin yanzu, wannan tsari yana dauke su ya fi na kowa.

lipids

Key jiki da kuma sinadaran halaye na membrane Layer aka bayar, da abubuwa nuna - phospholipids kunshi nonpolar (hydrophobic) wutsiya da wani iyakacin duniya (hydrophilic) kai. Mafi na kowa daga gare su, suna dauke phosphoglycerides da sphingolipids. Recent mayar da hankali, yafi a cikin matsanancin monolayer. Bã su da wani dangane da oligosaccharide sarƙoƙi. Saboda gaskiya cewa links mika bayan da m ɓangare plasmolemma, da ta samu wani asymmetrical siffar. Glycolipids taka muhimmiyar rawa a cikin aiwatar da na'ura surface tsoka mai amsa sigina aiki. Kamar yadda wani ɓangare na masu rinjaye na membrane ne ma cholesterol (cholesterol) - a steroid sia. Lambar ne daban-daban, wanda aka fi mayar da m da ruwa membrane. A mafi cholesterol, don haka shi ne a sama. ruwa matakin kuma ya dogara da rabo daga unsaturated da cikakken m acid sharan. A mafi daga gare su, don haka ne a sama. Liquid shafi na ayyuka na enzymes a cikin membrane.

sunadaran

Lipids m yafi shamaki Properties. Sunadaran, da bambanci, taimakawa ga aiwatar da key ayyuka na cell. A musamman, da sarrafawa da kai daga mahadi, metabolism tsari, liyafar da sauransu. Sunadarai na gina jiki rarraba a cikin lipid bilayer wata mosaic. Su za a iya koma a cikin ciki. Wannan yunkuri da aka sarrafawa da, a fili, da cell kanta. A kai inji hannu microfilaments. Suna a haɗe zuwa mutum na game da sunadarai. A membrane abubuwa ne daban-daban dangane da wuri dangane da bilipidnomu Layer. Sunadaran iya haka a gefe da kuma na game. A farko Layer aka sarrafa. Bã su da wani tenuous dangane da membrane surface. Na game sunadarai na gaba daya na nutsa cikin zurfin shi. Bã su da wani karfi bond tare da lipids, kuma rabu da membrane ba tareda žata bilipidnogo Layer. Sunadaran cewa, shiga ta hanyar da shi, da ake kira transmembrane. Hulda tsakanin gina jiki da kuma sia kwayoyin na daban-daban yanayi na samar da plasmalemma kwanciyar hankali.

glycocalyx

Lipoproteins da gefen sarƙoƙi. A oligosaccharide kwayoyin iya daura to lipids da glycolipids form. Su carbohydrate rabo tare da irin wannan abubuwa a haɗe zuwa tantanin halitta surface glycoproteins korau cajin da kuma samar da kashin baya na glycocalyx. Ya gabatar da wani sako-sako da Layer na matsakaici electron yawa. Glycocalyx rufe da m ɓangare plasmolemma. Its carbohydrate rabo sauƙaƙe fitarwa na makwabtaka da Kwayoyin da abubuwa therebetween, da kuma samar da m dangane da shi. A glycocalyx ma ba gitosovmestimosti da hormone rabe, enzymes.

bugu da žari

Matattarar rabe ne, yafi wakilta glycoproteins. Bã su da ikon kafa sadarwar da wani sosai musamman ligands. Rabe ba a cikin membrane, a Bugu da kari, za a iya tsara da motsi na wasu kwayoyin a cikin cell permeability na jini membrane. Sun iya maida sakonni daga yanayi a cikin ciki, nauyin abubuwa na extracellular matrix da cytoskeleton. Wasu masu bincike yi imani da cewa abun da ke ciki na glycocalyx ma ya hada da poluintegralnye sunadarai na gina jiki. Su aikin yankunan suna located a yankin na surface na cell nadmembrannoy na'ura.