Cov ntshav membrane: muab zais ciam teb rau lwm

lub neej ntawm ib tug cell ua tau xwb vim hais tias txawv enzymes thiab tshuaj tsis sib tov, thiab lub cell yog kev ncaj ncees. Tag nrho cov no yog tsuas ua tau los ntawm ib tug ntau yam ntawm week. A cell yog feem ntau delimited los ntawm lwm yam tshwj xeeb cov qauv npe hu ua "cytoplasmic membrane."

Pom seb nws yog ib tug teeb tshuab kuaj kab mob? Cov lus teb yog tsis muaj, yog, peb pom cov ciam teb, tab sis cov daim nyias nyias tus kheej - ib yam nkaus thiab zoo qauv. Tej zaum peb tsis pom txawm rau ib thaj tsam ntawm lub hlwb, piv txwv li, thaum uas nyob hauv lub teeb tshuab kuaj kab mob hauv lub siab lub hlwb. Tab sis yog vim li cas ces peb pom nyob rau hauv lwm tus neeg mob, cell ciam teb rau lwm, seb nws yog ib tug nyias nyias?

Nyob rau hauv qhov tseeb nws nadmembrannye khaubncaws sab nraud povtseg ntawm carbohydrates, uas yog nyob nruab nrab ntawm lub hlwb. Lawv nqus cov xim, yog li tej zaum koj yuav xav hais tias qhov no yog cov ntshav membrane nrog ib tug muaj kev vam meej txiav.

Nyob rau hauv thwmsim nws pom hais tias hlwb uas tau raug raus rau hauv kev daws teeb meem uas txawv osmotic siab, swell los yog ntsws, uas txhais tau tias lawv yog surrounded los ntawm ib tug membrane uas yog yus muaj los ntawm cov xim permeability.

Nws twb tseem qhia hais tias lub cell daim nyias nyias yog ib tug zoo-permeable, yog hais tias nws xav nkag rau yam tshuaj uas yog soluble nyob rau hauv lipids. Nyob rau hauv lub classical tswvyim gidrofilnye xaus ntawm daim nyias nyias molecules xam tau tias yog txojkev tawm sab nraud thiab lub hydrophobic - sab hauv. Electron microscopy kuj muaj pov thawj hais tias nws yog ntau npaum li cas yooj yim. Nyob rau hauv kev, hauv cov duab yuav pom tias lub txheej khaubncaws sab nraud povtseg yog tuab, thiab tsis nrog, piv txwv li lipid khaubncaws sab nraud povtseg nyob rau ntawm lub npoo.

Cov ntshav membrane los ntawm lawv cov ntaus ntawv impermeable mus macromolecules, li ntawd, cytoplasmic cov nqaijrog yog tsis muaj peev xwm kom tau tawm ntawm lub cell los ntawm nws. Cov nqaijrog yog nyob rau hauv lub cell, tsim osmotic siab, thiaj li hais tias txoj cai npaum li cas ntawm cov dej tau txais mus rau hauv lub cell. Txawm li cas los, txoj kev no tsis yog infinite, vim hais tias nyob rau hauv lub interstitial kua los ntawm sab nraum, ib yam nkaus thiab, muaj lwm cov tshuaj uas tswj qhov osmotic siab.

Rau tej qhov sib txawv tseem ruaj khov plasmatic membrane yuav tsum tau muaj dielectric zog. Nws kuj qhia zaum xav hais tias ib tug ntau ntawm daim nyias nyias lipids, uas muaj dielectric zog. Wb qhia nws cov khoom ntshav membrane.

Tus qauv thiab nws cov kev khiav dej num yog txuam, e.g., ib tug txawv txawv muaj peev xwm ua kom muaj qhov sib txawv nyob rau hauv lub tsi ntsees ntawm poov tshuaj thiab sodium ions yog txuam nrog ib tug tshwj xeeb mechanism nyob rau hauv daim nyias nyias - sodium-poov tshuaj twj tso kua mis. Ion hloov li muab ib qho enzyme uas ua hauj lwm nyob rau hauv lub zog hlwb, cov txheej txheem yog kim rau nws. Lub cell yuav tsum "them" rau qhov nqi koj tshuav. Tsis tas li ntawd yuav tsum tau "kev nqis peev" thiab cov kev hloov ntawm qabzib, fatty acids, amino acids.

Ib tug interesting feature ntawm tus xovtooj ntawm membrane raws li nws yog asymmetric, uas yog, nws puab thiab txheej chaw yog tsis tau tib yam, txawm hais tias tus thawj soj ntsuam nyob rau hauv lub hauv paus ntawm electron microscopy cov ntaub ntawv xam tau tias yog nyob rau hauv no txoj kev. Tag nrho cov qhov chaw carbohydrate-muaj glycoprotein molecules protrude tshaj lub txheej saum npoo ntawm daim nyias nyias thiab muab kev koom tes nyob rau hauv lub tsim nadlipidnogo txheej. Cov txheej nto ntawm lub cell kuj muaj tshwj xeeb molecules hu ua receptors, lawv muaj kev cuam tshuam rau tej molecules ntawm ib puag ncig. Yog li cai kev ua si ntawm lub cell, nws muaj peev xwm tsim kho los yog suppress nyob rau hauv lub cev cov kev xav tau. Thiab nyob rau hauv lub puab yog ib feem ntawm daim nyias nyias muaj ib tug ntau ntawm cov roj uas txhaws taus.

Biochemical kev tshawb fawb tau qhia lub cell daim nyias nyias, proteins uas cov puab thiab txheej week yog tsis zoo tib yam, tab sis txawv phospholipids nyob rau hauv nyob tus yeees ntawm cov ob chaw yog tseem heev ntau haiv neeg. Ib txhia ntawm cov yam ntxwv yuav pom txawm nrog ib tug electron tshuab kuaj kab mob.

Raws li koj tau pom, lub elementary membrane yog tsis yog li ntawd yooj yim, tab sis nyob rau hauv thiaj li yuav to taub tag nrho cov txheej txheem, cov zaum yuav tsum tau tsim kom muaj thiab yuav tsis tau txais ntau hypotheses.