Cells ntawm cov nroj tsuag, fungi thiab tsiaj muaj xws li peb yam xws li lub nucleus, lub cytoplasm nrog organelles thiab inclusions nyob rau hauv nws, thiab cov plasma membrane. Lub nucleus yog lub luag haujlwm khaws cia cov khoom siv caj ces kaw rau ntawm DNA, thiab tseem tswj hwm tag nrho cov txheej txheem ntawm tes. Lub cytoplasm muaj cov organelles, txhua tus muaj nws lub luag haujlwm, xws li, piv txwv li, kev sib txuas ntawm cov organic tshuaj, cellular respiration, cellular digestion, thiab lwm yam.
Dab tsi yog daim nyias nyias hauv biology?
Hais lus yooj yim, nws yog lub plhaub. Txawm li cas los xij, nws tsis yog ib txwm impenetrable. Kev thauj ntawm qee yam khoom los ntawm daim nyias nyias yuav luag ib txwm tso cai.
Nyob rau hauv cytology, daim nyias nyias tuaj yeem muab faib ua ob hom loj. Thawj yog lub plasma membrane uas npog lub cell. Qhov thib ob yog cov membranes ntawm organelles. Muaj organelles uas muaj ib los yog ob daim nyias nyias. Ib leeg-membrane suav nrog Golgi complex, endoplasmic reticulum, vacuoles, lysosomes. Plastids thiab mitochondria belongs rau ob-membrane ones.
Membranes kuj tuaj yeem nyob hauv cov organelles. Feem ntau lawv yog derivatives ntawm lub puab membraneOb-membrane organelles.
Cov membranes ntawm ob-membrane organelles ua li cas?
Plastids thiab mitochondria muaj ob lub plhaub. Cov txheej membrane ntawm ob lub organelles yog du, tab sis sab hauv yog tsim cov qauv tsim nyog rau kev ua haujlwm ntawm cov organoid.
Yog li, lub plhaub ntawm mitochondria muaj qhov tawm sab hauv - cristae lossis ridges. Lub voj voog ntawm cov tshuaj tiv thaiv tsim nyog rau kev ua pa ntawm tes yuav tshwm sim rau lawv.
Derivatives ntawm lub puab daim nyias nyias ntawm chloroplasts yog disk zoo li lub hnab - thylakoids. Lawv tau sau rau hauv pawg - nplej. Sib cais grana sib xyaw ua ke nrog kev pab ntawm lamellae - cov qauv ntev kuj tsim los ntawm daim nyias nyias.
qauv ntawm daim nyias nyias ntawm ib leeg-membrane organelles
Cov kab mob no tsuas muaj ib daim nyias nyias xwb. Nws feem ntau yog lub plhaub du ntawm lipids thiab cov proteins.
Txoj kev ntawm cov qauv ntawm cov plasma membrane ntawm cov cell
Cov daim nyias nyias yog tsim los ntawm cov khoom xws li lipids thiab cov proteins. Cov qauv ntawm cov plasma membrane muab rau nws thickness ntawm 7-11 nanometers. Feem ntau ntawm daim nyias nyias yog lipids.
Cov qauv ntawm cov plasma membrane muab rau muaj ob txheej hauv nws. Thawj yog ob txheej ntawm phospholipids thiab qhov thib ob yog txheej ntawm cov protein.
Plasma membrane lipids
Lipids uas ua rau cov ntshav plasma tau muab faib ua peb pawg: steroids, sphingophospholipids thiab glycerophospholipids. Lub molecule ntawm lub tom kawg muaj ib tug trihydric cawv residueglycerol, nyob rau hauv uas cov hydrogen atoms ntawm ob pawg hydroxyl yog hloov los ntawm chains ntawm fatty acids, thiab cov hydrogen atom ntawm peb hydroxyl pawg yog hloov los ntawm ib tug phosphoric acid residue, uas, nyob rau hauv lem, residue ntawm ib tug nitrogenous bases. yog txuas.
A glycerophospholipid molecule tuaj yeem muab faib ua ob ntu: lub taub hau thiab tails. Lub taub hau yog hydrophilic (uas yog, nws dissolves nyob rau hauv dej), thiab tails yog hydrophobic (lawv repel dej, tab sis yaj nyob rau hauv cov organic solvents). Vim yog cov qauv no, cov molecule ntawm glycerophospholipids tuaj yeem hu ua amphiphilic, piv txwv li ob qho tib si hydrophobic thiab hydrophilic tib lub sijhawm.
Sphingophospholipids yog tshuaj zoo ib yam li glycerophospholipids. Tab sis lawv txawv ntawm cov uas tau hais los saum toj no nyob rau hauv lawv cov muaj pes tsawg leeg, es tsis txhob ntawm glycerol residue, lawv muaj sphingosine cawv residue. Lawv cov molecules kuj muaj taub hau thiab tails.
Daim duab hauv qab no qhia meej cov qauv ntawm cov plasma membrane.
YPlasma membrane proteins
Raws li cov proteins uas tsim cov plasma membrane, cov no yog cov glycoproteins.
Nyob ntawm lawv qhov chaw nyob hauv lub plhaub, lawv tuaj yeem muab faib ua ob pawg: peripheral thiab ib qho. Thawj yog cov uas nyob rau saum npoo ntawm daim nyias nyias, thiab qhov thib ob yog cov uas nkag mus rau tag nrho cov tuab ntawm daim nyias nyias thiab nyob rau hauv cov lipid txheej.
Nyob ntawm cov haujlwm uas cov proteins ua, lawv tuaj yeem muab faib ua plaub pawg: enzymes, qauv, thauj thiab receptor.
Txhua cov proteins uas nyob hauv cov qauv ntawm cov plasma membrane tsis yog tshuaj lom neeg nrog phospholipids. Yog li ntawd, lawv tuaj yeem txav mus los hauv cov txheej txheem tseem ceeb ntawm daim nyias nyias, sib sau ua ke hauv pawg, thiab lwm yam. Yog li ntawd, cov qauv ntawm cov plasma membrane ntawm cov cell tsis tuaj yeem hu ua static. Nws yog dynamic raws li nws hloov txhua lub sijhawm.
Lub luag haujlwm ntawm phab ntsa cell yog dab tsi?
Cov qauv ntawm cov plasma membrane tso cai rau nws ua tsib lub luag haujlwm.
Ua ntej thiab qhov tseem ceeb - kev txwv ntawm cytoplasm. Vim li no, lub xov tooj ntawm tes muaj qhov zoo li qub thiab loj. Qhov kev ua haujlwm no tau lees paub los ntawm qhov tseeb tias cov plasma membrane muaj zog thiab elastic.
Lub luag haujlwm thib ob yog los xyuas kom muaj kev sib cuag ntawm tes. Vim lawv elasticity, cov plasma daim nyias nyias ntawm cov tsiaj hlwb muaj peev xwm tsim outgrowths thiab folds ntawm lawv junctions.
Lub luag haujlwm tom ntej ntawm cell membrane yog thauj. Nws yog muab los ntawm cov protein tshwj xeeb. Ua tsaug rau lawv, cov khoom tsim nyog tuaj yeem thauj mus rau hauv lub cell, thiab cov khoom tsis tsim nyog tuaj yeem muab pov tseg los ntawm nws.
Tsis tas li ntawd, cov ntshav plasma ua haujlwm ua haujlwm enzymatic. Nws kuj yog los ntawm cov proteins.
Thiab qhov kawg ua haujlwm yog teeb liab. Vim qhov tseeb tias cov proteins nyob rau hauv kev cuam tshuam ntawm qee yam kev mob tuaj yeem hloov lawv cov qauv spatial, cov plasma membrane tuaj yeem xa cov cim rau cov hlwb.
Tam sim no koj paub txhua yam txog daim nyias nyias: dab tsixws li ib daim nyias nyias nyob rau hauv biology, lawv yog dab tsi, yuav ua li cas lub plasma daim nyias nyias thiab daim nyias nyias ntawm organelles yog teem, lawv ua dab tsi.
