Cells uas tsim cov ntaub so ntswg ntawm cov neeg sawv cev ntawm flora thiab fauna muaj qhov sib txawv loj, zoo li, thiab cov ntsiab lus. Txawm li cas los xij, txhua tus ntawm lawv qhia qhov zoo sib xws hauv cov yam ntxwv tseem ceeb ntawm kev loj hlob, metabolism, kev ua haujlwm tseem ceeb, kev chim siab, muaj peev xwm hloov pauv, thiab kev loj hlob. Tom ntej no, cia peb saib ze dua ntawm cov qauv ntawm cov nroj tsuag ntawm tes (ib lub rooj ntawm cov khoom tseem ceeb yuav muab rau hauv qhov kawg ntawm tsab xov xwm).
Brief keeb kwm yav dhau
Nrog kev pab ntawm osmotic shock nyob rau hauv 1925, Grendel thiab Gorter tau npliag erythrocyte shells, lawv thiaj li hu ua "shadows". Lawv tau muab tso rau hauv ib pawg, txiav txim siab lawv thaj chaw. Lipids raug cais los ntawm acetone. Lawv tus lej ntawm ib cheeb tsam ntawm erythrocytes kuj tau txiav txim siab. Txawm hais tias muaj qhov yuam kev hauv kev suav, qhov txiaj ntsig raug raug txiav tawm thiab pom cov lipid bilayer.
cov ntaub ntawv dav dav
Biology yog kev kawm txog kev loj hlob thiab kev loj hlob ntawm cov ntaub so ntswg ntawm cov neeg sawv cev ntawm cov tsiaj thiab tsiaj. Cov qauv ntawm cov nroj tsuag cell yog ib tug complexpeb inextricably txuas Cheebtsam:
- Lub ntsiab. Nws yog cais los ntawm cytoplasm los ntawm ib tug ntxeem tau membrane. Nws muaj cov nucleolus, nuclear sap thiab chromatin.
- Cytoplasm thiab cov txheej txheem tshwj xeeb - organelles. Cov tom kawg, tshwj xeeb, suav nrog plastids, mitochondria, lysosomes thiab Golgi complex, cell center. Organelles yeej ib txwm muaj. Ntxiv rau lawv, kuj tseem muaj kev tsim ib ntus hu ua inclusions.
- Cov qauv uas tsim cov saum npoo yog lub plhaub ntawm cov nroj tsuag.
Txoj kev ntawm cov cuab yeej nto
Nyob rau hauv leukocytes thiab unicellular kab mob, lub cell membrane muab nkag mus rau hauv dej, ions, me me molecules ntawm lwm cov tebchaw. Cov txheej txheem thaum lub sij hawm nkag mus ntawm cov khoom uas tshwm sim yog hu ua phagocytosis. Yog tias cov kua dej poob qis, lawv hais txog pinocytosis.
Organoids
Lawv muaj nyob hauv cov hlwb eukaryotic. Kev hloov pauv lom neeg uas tshwm sim hauv cell yog txuam nrog organelles. Lawv npog los ntawm ob daim nyias nyias - plastids thiab mitochondria. Lawv muaj lawv tus kheej DNA, nrog rau cov khoom siv hluavtaws protein. Kev yug me nyuam yog los ntawm kev faib. Nyob rau hauv mitochondria, ntxiv rau ATP, protein yog synthesized nyob rau hauv ib tug me me npaum li cas. Plastids muaj nyob rau hauv cov nroj tsuag. Lawv kev yug me nyuam yog ua los ntawm kev faib.
Nws yog qhov yuam kev los xav tias txheej txheej ntawm tes yog cytoplasm. Lub membrane yog molecular elastic qauv. Lub txheej txheej ntawm tes yog hu uanto apparatus, los ntawm kev sib cais ntawm cov ntsiab lus los ntawm ib puag ncig sab nraud yog nqa tawm. Muaj cov haujlwm sib txawv ntawm cov cell membrane. Ib qho ntawm cov haujlwm tseem ceeb yog los xyuas kom meej qhov kev ncaj ncees ntawm tag nrho cov khoom. Sab hauv, kuj tseem muaj cov qauv uas faib cov cell mus rau hauv qhov hu ua compartments. Cov chaw kaw no yog hu ua organelles lossis compartments. Nyob rau hauv lawv, tej yam kev mob yog khaws cia. Lub luag haujlwm ntawm lub cell membrane yog tswj kev sib pauv ntawm ib puag ncig thiab lub cell.
Tus qauv ntawm cov cell membrane yog dab tsi? Lub cell membrane yog bilayer (ob npaug) ntawm lipid class molecules. Feem ntau ntawm lawv yog lipids ntawm ib hom complex - phospholipids. Molecules muaj hydrophobic (tail) thiab hydrophilic (lub taub hau). Thaum cov phab ntsa ntawm tes tsim, cov tails tig mus rau sab hauv, thiab lub taub hau tig mus rau sab nraud. Membranes yog cov qauv tsis sib xws. Lub plhaub ntawm cov tsiaj cell muaj ntau yam zoo sib xws nrog cov khoom ntawm tus neeg sawv cev ntawm cov nroj tsuag. Lub thickness ntawm daim nyias nyias yog li 7-8 nm. Cov txheej txheem lom neeg sab nraud ntawm lub xovtooj suav nrog ntau cov protein sib txuas: semi-integral (ntawm ib qho kawg rau hauv cov txheej txheem lipid sab hauv), cov khoom sib xyaw (xws li nkag mus), nto (nyob ib sab rau sab hauv lossis nyob rau sab nraud). Ib tug xov tooj ntawm cov proteins yog cov ntsiab lus sib txuas ntawm daim nyias nyias thiab cytoskeleton hauv lub cell thiab sab nrauv phab ntsa (yog tias muaj). Qee qhov sib xyaw ua ke ua raws li ion channels, ntau yam receptors thiab transporters.
haujlwm tiv thaiv
Cov qauv ntawm cov cell membrane feem ntau txiav txim siab nws txoj haujlwm. Hauv particular, daim nyias nyias muaj kev xaiv permeability. Qhov no txhais tau hais tias qhov degree ntawm permeability ntawm molecules los ntawm daim nyias nyias nyob ntawm lawv qhov loj me, tshuaj lom neeg, thiab cov nqi hluav taws xob. Lub luag haujlwm tseem ceeb uas txheej txheej txheej ntawm tes ua yog hu ua barrier. Vim nws, ib qho kev xaiv, tswj, nquag thiab passive pauv ntawm cov tebchaw nrog ib puag ncig yog guaranteed. Piv txwv li, daim nyias nyias ntawm peroxisomes tiv thaiv cytoplasm los ntawm peroxides txaus ntshai.
Kev thauj mus los
Los ntawm txheej txheej ntawm tes muaj kev hloov pauv ntawm cov tshuaj. Vim yog kev thauj mus los, kev xa khoom ntawm cov khoom noj khoom haus, kev tshem tawm cov khoom kawg ntawm cov txheej txheem metabolic, tso tawm ntau yam tshuaj, thiab tsim cov khoom xyaw ionic. Tsis tas li ntawd, qhov zoo tshaj pH thiab cov ntsiab lus ntawm ions tsim nyog rau kev ua haujlwm ntawm cov enzymes yog khaws cia hauv lub cell. Yog tias vim li cas cov khoom tsim nyog tsis tuaj yeem dhau los ntawm phospholipid bilayer, piv txwv li, vim muaj cov khoom siv hydrophilic, vim tias daim nyias nyias yog hydrophobic sab hauv, los yog vim lawv loj, lawv tuaj yeem hla daim nyias nyias los ntawm cov khoom thauj tshwj xeeb (carrier proteins), los ntawm endocytosis los yog los ntawm cov protein raws. Nyob rau hauv tus txheej txheem ntawm kev thauj mus los passive, cov tebchaw dhau los ntawm txheej txheej ntawm tes tsis muaj nqi zog los ntawm diffusion raws qhov concentration gradient. Kev siv lub teeb hnyav yog suav tias yog ib qho ntawm cov kev xaiv rau cov txheej txheem no. Nyob rau hauv cov ntaub ntawv no, ib tug tshwj xeeb molecule pab cov khoom mus hla lub txheej txheej ntawm tes. Nws ua taumuaj cov channel uas muaj peev xwm kis tau cov tshuaj ntawm hom 1 nkaus xwb. Kev thauj mus los yuav tsum muaj zog. Qhov no yog vim lub fact tias lub zog nyob rau hauv cov ntaub ntawv no tshwm sim inversely mus rau lub concentration gradient. Hauv qhov no, daim nyias nyias muaj cov twj tso kua mis tshwj xeeb, suav nrog ATPase, uas nquag nqus cov poov tshuaj ions rau hauv lub cell thiab tso tawm sodium ions.
Lwm txoj haujlwm
Txheej txheej ntawm tes ua haujlwm matrix. Qhov no ua kom muaj kev sib koom ua ke thiab kev taw qhia ntawm cov membrane protein sib txuas, nrog rau lawv cov kev sib raug zoo. Vim lub tshuab ua haujlwm, kev ywj pheej ntawm cov xovtooj ntawm tes thiab cov qauv sab hauv, nrog rau kev sib txuas nrog lwm cov hlwb, yog ua kom ntseeg tau. Hauv qhov no, cov phab ntsa ntawm cov qauv yog qhov tseem ceeb hauv cov neeg sawv cev ntawm cov nroj tsuag. Nyob rau hauv cov tsiaj, kev muab cov neeg kho tshuab muaj nuj nqi nyob ntawm cov khoom intercellular. Membranes kuj ua haujlwm lub zog. Nyob rau hauv cov txheej txheem ntawm photosynthesis nyob rau hauv chloroplasts thiab cellular respiration nyob rau hauv mitochondria, lub zog hloov mus rau hauv lawv cov phab ntsa. Nyob rau hauv lawv, zoo li nyob rau hauv ntau lwm yam, proteins koom nrog. Ib qho tseem ceeb tshaj plaws yog kev ua haujlwm receptor. Qee cov proteins uas pom hauv daim nyias nyias yog receptors. Ua tsaug rau cov molecules no, lub xovtooj ntawm tes tuaj yeem pom qee cov cim. Piv txwv li, steroids circulating nyob rau hauv cov hlab ntsha cuam tshuam tsuas yog cov hom phiaj hlwb uas muaj receptors sib xws rau tej yam tshuaj hormones. Tseem muaj cov neurotransmitters. Cov tshuaj nokev sib txuas muab impulse kis tau tus mob. Lawv kuj muaj kev koom tes nrog cov hom phiaj tshwj xeeb. Membrane Cheebtsam feem ntau yog cov enzymes. Yog li ntawd, kev ua haujlwm enzymatic ntawm lub cell membrane. Cov tshuaj digestive muaj nyob rau hauv cov plasma daim nyias nyias ntawm cov hnyuv epithelial. Biopotentials yog tsim thiab ua nyob rau hauv txheej txheej ntawm tes.
Ion concentration
Nrog kev pab los ntawm daim nyias nyias, cov ntsiab lus sab hauv ntawm K + ion yog khaws cia ntawm qib siab dua sab nraud. Nyob rau tib lub sijhawm, Na + concentration yog qis dua sab nraud. Qhov no yog qhov tseem ceeb tshwj xeeb vim tias nws muaj peev xwm sib txawv ntawm phab ntsa thiab tiam ntawm cov paj hlwb.
Marking
Muaj cov tshuaj tiv thaiv ntawm daim nyias nyias uas ua raws li qee yam "labels". Lub cim tso cai rau lub xov tooj los txheeb xyuas. Glycoproteins - cov proteins nrog oligosaccharide branched sab chains txuas rau lawv - ua lub luag haujlwm ntawm "antennas". Txij li thaum muaj suav tsis txheeb configurations ntawm sab chains, nws muaj peev xwm ua ib tug marker rau txhua pab pawg neeg ntawm cell. Nrog kev pab los ntawm lawv, qee lub ntsiab lus tau lees paub los ntawm lwm tus, uas, nyob rau hauv lem, tso cai rau lawv ua yeeb yam. Qhov no tshwm sim, piv txwv li, thaum lub sij hawm tsim cov ntaub so ntswg thiab lub cev. Raws li tib lub tswv yim, lub cev tiv thaiv kab mob ua haujlwm kom paub txog txawv teb chaws antigens.
Kev sib xyaw thiab qauv
Raws li tau hais los saum no, cell membranes yog tsim los ntawm phospholipids. Txawm li cas los xij, ntxiv rau lawv, cov qauv muajcholesterol thiab glycolipids. Cov tom kawg yog lipids nrog cov carbohydrates txuas. Glyco- thiab phospholipids, uas feem ntau tsim cov cell membranes, muaj 2 ntev hydrophobic carbohydrate "tails". Lawv yog txuam nrog ib tug hydrophilic, them "lub taub hau". Vim muaj cov roj cholesterol, daim nyias nyias muaj qhov tsim nyog ntawm rigidity. Lub compound occupies qhov chaw dawb ntawm lipid hydrophobic tails, yog li tiv thaiv lawv dabtsi yog khoov. Hauv qhov no, cov membranes uas muaj cov roj cholesterol tsawg yog hloov tau yooj yim thiab mos, thiab qhov twg muaj ntau dua, ntawm qhov tsis sib xws, muaj ntau dua rigidity thiab fragility nyob rau hauv cov phab ntsa. Tsis tas li ntawd, lub compound ua raws li ib tug stopper uas tiv thaiv kev txav ntawm polar molecules ntawm cell mus rau cell. Qhov tshwj xeeb tseem ceeb yog cov protein uas nkag mus rau hauv daim nyias nyias thiab muaj lub luag haujlwm rau nws cov khoom sib txawv. Ib los yog lwm lub plhaub ntawm cov nroj tsuag ntawm tes muaj cov proteins uas txhais tau hais tias muaj pes tsawg leeg thiab kev taw qhia.
Annular lipids
Cov tebchaw no muaj nyob ib sab ntawm cov proteins. Txawm li cas los xij, annular lipids tau xaj ntau dua thiab tsis tshua muaj mobile. Lawv muaj fatty acids uas muaj ntau saturation. Lipids tawm hauv daim nyias nyias ua ke nrog cov protein ntau. Yog tsis muaj annular ntsiab, membrane proteins yuav tsis ua hauj lwm. Feem ntau, lub plhaub yog asymmetrical. Hauv lwm lo lus, qhov no txhais tau hais tias cov txheej txheem muaj cov lipid sib txawv. Sab nraud muaj xws li glycolipids, sphingomyelins, phosphatidylcholine, phosphatidyl nositol. Sab hauv txheej muaj phosphatidyl nositol,phosphatidylserine thiab phosphatidylserine. Kev hloov ntawm ib qib mus rau lwm qhov tshwj xeeb molecule yog qhov nyuaj me ntsis. Txawm li cas los xij, nws tuaj yeem tshwm sim spontaneously. Qhov no tshwm sim ib zaug txhua rau lub hlis. Kev hloov pauv tuaj yeem ua tau nrog kev pab ntawm flippase thiab scramblase proteins. Thaum phosphatidylseryl tshwm nyob rau hauv txheej txheej, macrophages siv txoj haujlwm tiv thaiv thiab coj lawv cov haujlwm los rhuav tshem lub cell.
Organelles
Cov cheeb tsam no tuaj yeem ua ib leeg thiab kaw lossis txuas rau ib leeg, sib cais los ntawm daim nyias nyias los ntawm hyaloplasm. Perixisomes, vacuoles, lysosomes, Golgi apparatus, thiab endoplasmic reticulum suav hais tias yog ib leeg-membrane organelles. Ob daim nyias nyias muaj xws li plastids, mitochondria, thiab cov nucleus. Raws li rau cov qauv ntawm daim nyias nyias, cov phab ntsa ntawm cov organelles sib txawv ntawm cov proteins thiab lipids.
Kev xaiv permeability
Los ntawm cov cell membranes maj mam faib cov rog thiab amino acids, ions thiab glycerol, qabzib. Nyob rau tib lub sijhawm, cov phab ntsa lawv tus kheej nquag tswj cov txheej txheem no, hla qee qhov thiab khaws lwm yam khoom. Muaj plaub lub ntsiab mechanisms rau kev nkag mus ntawm ib lub compound rau hauv ib lub cell. Cov no muaj xws li endo- lossis exocytosis, active thauj, osmosis thiab diffusion. Qhov kawg ob yog passive nyob rau hauv cov xwm thiab tsis xav tau lub zog nqi. Tab sis thawj ob yog active. Lawv xav tau lub zog. Nrog passive kev thauj mus los, xaiv permeability yog txiav txim los ntawm ib qho proteins - cov channel tshwj xeeb. Lub membrane yog permeated los ntawm lawv. Cov channel no tsim ib hom kev hla. Muaj cov protein ntau rau cov khoomCl, Na, K. Raws li rau cov concentration gradient, cov molecules ntawm lub ntsiab txav mus rau hauv lub cell los ntawm nws. Tawm tsam keeb kwm ntawm kev khaus khaus, sodium ion channel qhib. Lawv, nyob rau hauv lem, pib abruptly nkag mus rau hauv lub cell. Qhov no yog nrog los ntawm kev tsis sib haum xeeb hauv daim nyias nyias. Txawm li cas los xij, nws rov qab los. Potassium channels ib txwm qhib. Ions nkag mus rau hauv lub cell maj mam los ntawm lawv.
In xaus
Cov dej num thiab cov qauv ntawm cov nroj tsuag ntawm tes tau piav qhia luv luv hauv qab no. Cov lus tseem muaj cov ntaub ntawv hais txog cov khoom siv roj ntsha.
| Nyob ntawm cov ntsiab lus | Kev sib xyaw thiab kev ua haujlwm |
| Cob hlwb | Ua los ntawm fiber ntau. Muab scaffolding thiab tiv thaiv. |
| Bioelements | txheej nyias thiab elastic heev - glycocalyx suav nrog cov proteins thiab polysaccharides. Muab kev tiv thaiv. |
