Qhov sib txawv tseem ceeb ntawm prokaryotic thiab eukaryotic transcription yog qhov kev hloov pauv prokaryotic tshwm sim hauv cytoplasm thaum lub eukaryotic transcription tshwm sim hauv lub nucleus.
Nyob hauv ib lub xovtooj, DNA nqa cov ntaub ntawv los ntawm ib tiam dhau ib tiam los tswj cov haujlwm ntawm lub xovtooj. Tsis tas li ntawd, DNA yog lub luag haujlwm rau kev sib txuas tag nrho cov proteins uas muaj kev ua haujlwm zoo li lub luag haujlwm hauv lub cell. Yog li ntawd, los ntawm kev tsim cov proteins no, DNA tswj cov haujlwm ntawm lub xovtooj. Ib lub noob uas muaj cov ntaub ntawv caj ces los tsim cov protein yuav tsum tau nthuav tawm txhawm rau txhawm rau tsim cov protein sib luag. Gene qhia tshwm sim ntawm ob kauj ruam tseem ceeb xws li kev sau thiab txhais lus. Li no, transcription yog thawj kauj ruam ntawm gene qhia. Nws yog ua raws li kev txhais lus. Thaum lub sij hawm transcription, cov ntaub ntawv caj ces ntawm DNA hloov mus rau hauv peb tsab ntawv genetic code sequence hauv mRNA. Thaum lub sijhawm txhais lus, mRNA hloov mus rau hauv cov saw hlau ntawm polypeptides.
Prokaryotic Transcription yog dab tsi?
Prokaryotic transcription tshwm sim nyob rau hauv lub cytoplasm. Tsis tas li ntawd, nws yeej ib txwm tshwm sim ua ke nrog kev txhais lus. Transcription nyob rau hauv lub cell prokaryotic muaj plaub theem: khi, pib, elongation thiab txiav. RNA polymerase yog cov enzyme uas catalyzes synthesis ntawm mRNA strand. Kev khi ntawm RNA polymerase rau cov txheej txheem txhawb nqa yog thawj kauj ruam hauv kev sau ntawv. Nyob rau hauv cov kab mob ntawm tes, tsuas yog ib hom RNA polymerase muaj nyob uas synthesizes tag nrho cov chav kawm ntawm RNA: mRNA, tRNA thiab rRNA. RNA polymerase pom nyob rau hauv Escherichia coli (E coli) muaj ob α subunits thiab ob β subunits thiab ib tug sigma yam.
Daim duab 01: Prokaryotic Transcription
Thaum qhov kev ua sigma no khi rau DNA txhawb nqa ib ntus uas ua rau tsis muaj DNA ob chav helix, pib tshwm sim. Siv ib qho ntawm cov DNA strands ua tus qauv, RNA polymerase synthesizes RNA strand txav raws DNA strand unwinding lub helix hauv 5' rau 3' kev taw qhia. Li no, thaum lub sij hawm elongation kauj ruam, no RNA strand hlob los ntawm 5′ mus rau 3′ ua ib tug luv luv hybrid nrog cov DNA strand. Thaum qhov kev txiav tawm ua tiav tiav, elongation ntawm mRNA sequence ceases. Hauv prokaryotes, muaj ob hom kev txiav tawm; factor-dependent termination thiab intrinsic termination. Qhov cuam tshuam ntawm kev txiav txim siab xav tau Rho yam, thiab qhov kev txiav tawm ntawm lub cev tshwm sim thaum tus qauv muaj qhov luv GC nplua nuj nyob ze ntawm 3' kawg tom qab ob peb lub hauv paus uracil.
Eukaryotic Transcription yog dab tsi?
Eukaryotic transcription tshwm sim nyob rau hauv lub nucleus. Zoo ib yam li prokaryotic transcription, eukaryotic transcription kuj tshwm sim ntawm plaub kauj ruam, piv txwv li, khi, pib, elongation thiab txiav. Txawm li cas los xij, eukaryotic transcription yog qhov nyuaj dua li cov ntaub ntawv prokaryotic.
Nyob hauv eukaryotic cell, muaj peb hom RNA polymerases; lawv yog namely, RNA pol I, II thiab III thiab lawv txawv ntawm lawv qhov chaw thiab hom RNA lawv synthesize. RNA polymerase khi nrog DNA ntawm thaj chaw txhawb nqa nrog kev pab ntawm cov khoom siv hloov pauv. Thaum DNA helix unwinds rau hauv ib leeg, RNA polymerase catalyzes cov synthesis ntawm mRNA ib ntus los ntawm cov qauv strand. Qhov no RNA strand hlob los ntawm 5′ mus rau 3′ ua ib tug luv luv hybrid nrog DNA strand, thiab uas yog hu ua elongation. Elongation yog ceased nrog lub transcription ntawm ib tug tshwj xeeb ib theem zuj zus hu ua ib tug termination teeb liab. Kev txiav tawm yog tswj hwm los ntawm ntau yam teeb liab uas sib txawv nrog cov enzyme koom nrog.
Daim duab 02: Eukaryotic Transcription
Ntxiv mus, qhov pib RNA ib ntus uas tau los ntawm kev hloov pauv yog qhov RNA ntxov ntxov. Nws muaj cov kab ke khib nyiab. Li no, ua ntej kev txhais lus, qee qhov kev hloov kho tshwm sim txhawm rau tsim mRNA paub tab. Cov kev hloov kho no suav nrog RNA splicing, 5 'capping, 3' adenylation, thiab lwm yam. Thaum cov kev hloov kho tau tshwm sim, mRNA sib lawv liag mus rau cytoplasm. Tsis zoo li hauv prokaryotes, eukaryotic transcription tsis tshwm sim ib txhij nrog kev txhais lus.
Dab tsi zoo sib xws ntawm Prokaryotic thiab Eukaryotic Transcription?
- Ob leeg prokaryotic thiab eukaryotic transcription ua raws tib lub tswv yim.
- Tsis tas li, ob leeg muaj cov kauj ruam zoo sib xws.
- Thaum kawg ntawm ob txheej txheem, ib qho mRNA tsim tawm.
- Tsis tas li ntawd, RNA polymerase catalyzes ob txheej txheem kev hloov pauv.
- Dhau li ntawd, ob txheej txheem siv DNA qauv los tsim mRNA ib ntus.
Qhov txawv ntawm Prokaryotic thiab Eukaryotic Transcription yog dab tsi?
Prokaryotic transcription tshwm sim nyob rau hauv lub cytoplasm. Ntawm qhov tod tes, eukaryotic transcription tshwm sim nyob rau hauv lub nucleus. Qhov no yog qhov sib txawv tseem ceeb ntawm prokaryotic thiab eukaryotic transcription. Tsis tas li ntawd, prokaryotic transcription ua polycistronic mRNA thaum eukaryotic transcription ua monocistronic mRNA. Yog li, nws kuj yog qhov sib txawv ntawm prokaryotic thiab eukaryotic transcription. Tsis tas li ntawd, ib qho sib txawv ntxiv ntawm prokaryotic thiab eukaryotic transcription yog qhov prokaryotic transcription muaj ib hom RNA polymerase thaum eukaryotic transcription muaj peb hom RNA polymerases.
Ntxiv mus, lwm qhov sib txawv ntawm prokaryotic thiab eukaryotic transcription yog tias cov ntawv sau thiab kev txhais lus tau ua ke hauv prokaryotes thaum lawv tsis ua ke hauv eukaryotes. Tsis tas li ntawd, hauv prokaryotes, kev hloov pauv tom qab hloov pauv tsis tau tshwm sim thaum nyob hauv eukaryotes, tom qab hloov pauv hloov pauv tshwm sim. Yog li, nws kuj yog qhov sib txawv ntawm prokaryotic thiab eukaryotic transcription.
Hauv qab infographic ntawm qhov sib txawv ntawm prokaryotic thiab eukaryotic transcription muab cov ntaub ntawv ntau ntxiv ntawm qhov sib txawv.
Summary – Prokaryotic vs Eukaryotic Transcription
Kev txhais lus yog thawj kauj ruam ntawm cov noob qhia, uas ua raws li kev txhais lus. Txawm hais tias cov txheej txheem hloov pauv yog tib yam hauv prokaryotes thiab eukaryotes, muaj ntau qhov sib txawv ntawm lawv. Qhov sib txawv tseem ceeb ntawm prokaryotic thiab eukaryotic transcription yog qhov kev hloov pauv ntawm prokaryotic tshwm sim hauv cytoplasm thaum lub eukaryotic transcription tshwm sim hauv lub nucleus. Tsis tas li ntawd, prokaryotic transcription tsuas muaj ib qho RNA polymerase xwb thaum eukaryotic transcription suav nrog peb hom RNA polymerases. Ntxiv mus, mRNA ib theem zuj zus ntawm prokaryotes yog polycistronic thaum nyob rau hauv eukaryotes, mRNA sequence yog monocistronic. Tsis tas li ntawd, hauv eukaryotes, kev hloov pauv tom qab hloov pauv tshwm sim thaum nyob hauv prokaryotes, lawv tsis tshwm sim. Qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm prokaryotic thiab eukaryotic transcription.
