Video: Puas yog RNA polymerase ib qho kev hloov pauv?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Cov enzyme RNA polymerase , uas ua rau ib tug tshiab RNA molecule los ntawm DNA qauv, yuav tsum txuas mus rau DNA ntawm cov noob. Lawv yog ib feem ntawm lub cell core kev sau ntawv toolkit, xav tau rau lub kev sau ntawv ntawm tej gene. RNA polymerase khi rau tus neeg txhawb nqa nrog kev pab los ntawm cov txheej txheem protein hu ua general cov ntsiab lus ntawm kev txhais lus.
Yog li ntawd, puas yog RNA polymerase II ib qho kev hloov pauv?
Nws catalyzes kev sau ntawv DNA los tsim cov precursors ntawm mRNA thiab feem ntau snRNA thiab microRNA. 550 kDa complex ntawm 12 subunits, RNAP II yog hom kawm tshaj plaws ntawm RNA polymerase . Ntau yam ntawm cov ntsiab lus ntawm kev txhais lus yuav tsum tau rau nws los khi rau upstream gene promoters thiab pib kev sau ntawv.
Tom qab ntawd, lo lus nug yog, dab tsi yog qhov ua haujlwm ntawm qhov kev hloov pauv? Transcription yam yog cov proteins koom nrog hauv cov txheej txheem hloov pauv, lossis hloov pauv, DNA rau hauv RNA. Transcription yam suav nrog ntau cov proteins, tsis suav nrog RNA polymerase, uas pib thiab tswj cov kev sau ntawv ntawm cov noob. Kev cai ntawm kev sau ntawv yog hom kev tswj gene ntau tshaj plaws.
Ib yam li ntawd, tib neeg nug, ua cov ntsiab lus hloov pauv rau RNA polymerase?
Lawv muaj peev xwm khi ncaj qha mus rau tshwj xeeb "promoter" cheeb tsam ntawm DNA , uas yog nyob rau ntawm ntug dej ntawm coding cheeb tsam nyob rau hauv ib tug gene, los yog ncaj qha mus rau lub RNA polymerase molecule. Basal, los yog general, cov ntsiab lus ntawm kev txhais lus yog tsim nyog rau RNA polymerase ua haujlwm ntawm qhov chaw ntawm kev sau ntawv hauv eukaryotes.
Dab tsi yog lub luag haujlwm ntawm RNA polymerase hauv kev sau ntawv?
RNA polymerase (ntsuab) synthesizes RNA los ntawm kev ua raws li ib txoj hlua DNA. RNA polymerase yog ib qho enzyme uas yog lub luag haujlwm rau luam cov DNA ib ntus rau hauv ib qho RNA sequence, duyring txheej txheem ntawm kev sau ntawv . RNA polymerases tau pom nyob rau hauv txhua hom, tab sis tus naj npawb thiab muaj pes tsawg leeg ntawm cov proteins no txawv nyob rau hauv taxa.
Pom zoo:
Vim li cas tom qab kev hloov pauv kev hloov pauv tseem ceeb?
Kev hloov pauv tom qab kev txhais lus (PTMs) xws li glycosylation thiab phosphorylation ua lub luag haujlwm tseem ceeb ntawm kev ua haujlwm ntawm hemostatic proteins thiab tseem ceeb heev hauv kev teeb tsa kab mob. Xws li theem nrab hloov pauv rau cov proteins hemostatic muaj ntau yam cuam tshuam rau lawv lub peev xwm los cuam tshuam nrog lwm cov proteins
Dab tsi yog qhov txawv ntawm ib puag ncig kev hloov pauv thiab kev hloov pauv qub txeeg qub teg?
Qhov sib txawv ntawm cov yam ntxwv ntawm cov tib neeg ntawm tib hom yog hu ua variation. Qhov no yog inherited variation. Qee qhov kev hloov pauv yog qhov tshwm sim ntawm qhov sib txawv ntawm ib puag ncig, lossis ib tus neeg ua dab tsi. Qhov no yog hu ua environmental variation
Puas yog qhov kev hloov pauv yog ib qho kev tawm dag zog?
Rigid motion yog txwv tsis pub hu ua ib tug nruj transformation thiab tshwm sim thaum ib tug taw tes los yog khoom yog tsiv, tab sis qhov luaj li cas thiab cov duab nyob twj ywm tib yam. Qhov no txawv ntawm qhov tsis muaj zog, zoo li dilation, qhov loj ntawm cov khoom tuaj yeem nce lossis txo
Thaum ib qho kev sib cais ua rau muaj kev hloov pauv hloov pauv ntawm lub ntiaj teb nce ntxiv?
Txij li thaum lub kaw lus raug cais tawm, tsis muaj cua sov tuaj yeem khiav tawm (tus txheej txheem yog li adiabatic), yog li thaum lub zog ntws tawm hauv lub cev, qhov entropy ntawm qhov system nce, piv txwv li Δ Ssys> 0. Yog li ntawd, lub entropy ntawm lub system yuav tsum tau nce rau ib tug spontaneous txheej txheem nyob rau hauv no cais system
Puas yog kev tshem tawm ib qho kev hloov pauv?
Kev rho tawm kev hloov pauv tshwm sim thaum ib feem ntawm DNA molecule tsis tau theej thaum lub sijhawm DNA rov ua dua. Hauv ib qho kev hloov pauv ib qho yuam kev tshwm sim hauv ib qho nucleotide. Tag nrho lub hauv paus khub yuav ploj, lossis tsuas yog lub hauv paus nitrogenous ntawm tus tswv strand. Rau cov ntsiab lus tshem tawm, ib qho nucleotide tau raug tshem tawm ntawm qhov sib lawv liag