Cov txheej txheem:
Video: Dab tsi yog biological membranes muaj li ntawm?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Membranes yog tsim lipids, proteins thiab qab zib
Biological membranes muaj ntawm ob daim ntawv (lub npe hu ua bilayer) ntawm lipid molecules. Cov qauv no feem ntau hu ua phospholipid bilayer
Hauv qhov no, dab tsi yog cov khoom tseem ceeb ntawm cov kab mob lom?
Lub ntsiab Cheebtsam ntawm biological membranes yog cov proteins , lipids , thiab carbohydrates nyob rau hauv sib txawv proportions. Carbohydrates suav txog tsawg dua 10% ntawm qhov loj ntawm feem ntau daim nyias nyias thiab feem ntau khi rau ntawm lipid los yog protein ntau cov khoom. Myelin muaj ob peb lub luag haujlwm thiab yog tsim los ntawm yuav luag tag nrho lipids.
Ib tug kuj yuav nug, puas yog txhua daim nyias nyias muaj cov cholesterol? Txawm tias cholesterol yog tsis muaj nyob rau hauv cov kab mob, nws yog ib qho tseem ceeb ntawm cov tsiaj cell ntshav ntshav daim nyias nyias . Cog hlwb kuj tsis muaj cov roj cholesterol , tab sis lawv muaj Cov tshuaj sib xyaw ua ke (sterols) uas ua tiav cov haujlwm zoo sib xws. Cov kev tshawb fawb tsis ntev los no qhia tias tsis yog tag nrho lipids diffuse dawb hauv plasma daim nyias nyias.
Tom qab ntawd, ib tug kuj yuav nug, ua li cas cov kab mob lom ua?
A biological daim nyias nyias los yog biomembrane yog ib qho thaiv los yog sib cais daim nyias nyias uas ua raws li kev xaiv permeable barrier nyob rau hauv tej yam muaj sia. Feem ntau ntawm lipid nyob rau hauv ib lub cell daim nyias nyias muab cov kua matrix rau cov protein kom tig thiab tom qab diffuse rau kev ua haujlwm ntawm lub cev.
Dab tsi ntawm lipid yog qhov tseem ceeb tshaj plaws hauv cov kab mob lom neeg?
Membrane Lipids yog Amphipathic Molecules, feem ntau ntawm cov uas tshwm sim los ntawm Bilayers
- Lipid-uas yog, fatty-molecules tsim txog li 50% ntawm qhov loj ntawm feem ntau cov tsiaj cell membranes, yuav luag tag nrho cov seem yog protein.
- Qhov ntau tshaj lipids membrane yog phospholipids.
Pom zoo:
Dab tsi yog cov hlau nplaum uas ua los ntawm qhov kev npaj ntawm electrons yog dab tsi?
Electrons yog teem rau hauv plhaub thiab orbitals nyob rau hauv ib tug atom. Yog hais tias lawv sau lub orbitals kom muaj ntau spin taw tes rau hauv qab (los yog vice versa), txhua atom yuav ua zoo li ib tug me me hlau nplaum. Thaum ib daim ntawm cov hlau tsis muaj hlau nplaum (lossis lwm yam khoom siv ferromagnetic) raug rau sab nraud magnetic teb, ob yam tshwm sim
Dab tsi yog biological theories ntawm Ageing?
Cov txheej txheem kev laus ib txwm ntseeg tias kev laus tsis yog kev hloov pauv lossis kev ua haujlwm ntawm caj ces. Niaj hnub nimno biological theories ntawm kev laus hauv tib neeg poob rau hauv ob pawg loj: programmed thiab kev puas tsuaj lossis kev ua yuam kev. Biological moos ua los ntawm cov tshuaj hormones los tswj cov kev laus
Dab tsi yog cov tails ntawm phospholipids ntawm cov plasma membrane muaj li ntawm?
Phospholipids yog ib chav kawm ntawm lipids uas yog ib feem tseem ceeb ntawm tag nrho cov cell membranes. Lawv tuaj yeem tsim cov lipid bilayers vim lawv cov yam ntxwv amphiphilic. Cov qauv ntawm cov phospholipid molecule feem ntau muaj ob hydrophobic fatty acid 'tails' thiab ib tug hydrophilic 'lub taub hau' uas muaj ib pab pawg neeg phosphate
Txoj kev loj hlob ntawm kev puas siab puas ntsws biological yog dab tsi?
Kev loj hlob ntawm biological piav qhia txog kev hloov pauv ntawm lub cev uas tshwm sim txhawm rau hloov lub zygote rau hauv ib tus neeg laus. Cov lus qhia hauv tshooj no suav nrog cov xwm txheej thaum lub sijhawm cev xeeb tub uas yog qhov tseem ceeb rau kev loj hlob, nrog rau kev hloov pauv lom neeg uas tshwm sim thaum cev xeeb tub, hluas thiab laus
Dab tsi yog qhov flux los ntawm lub voos xwmfab ntawm sab yog tias tus nqi ntawm Q yog ntawm ib qho ntawm nws lub ces kaum?
Raws li peb paub tias, tag nrho cov flux los ntawm tus nqi q yog q / ε 0 (Gauss txoj cai). Yog hais tias tus nqi yog nyob rau ntawm lub ces kaum ntawm lub voos xwmfab, ib co ntawm cov flux nkag mus rau hauv lub voos xwmfab thiab tawm los ntawm ib co ntawm nws lub ntsej muag. Tab sis qee qhov flux tsis nkag mus rau hauv lub voos xwmfab. Qhov 1/8th no yuav muab faib ua 3 ntu dua