Qhov Tseem Ceeb Qhov Sib Txawv - Kev Sau Ntawv vs Rov Rov Qab Hloov
Kev txhais lus thiab txhais lus yog ob txoj haujlwm tseem ceeb koom nrog hauv kev qhia cov noob. Nws tuaj yeem muaj ob hom kev hloov pauv raws li kev ua haujlwm thiab cov enzyme siv. Lawv yog transcription thiab reverse transcription. Hauv kev sau ntawv, mRNA molecule yog tsim los ntawm DNA qauv thiab cov enzyme siv yog RNA polymerase. Kev hloov pauv rov qab, feem ntau yog siv los ntawm cov kab mob retroviruses, suav nrog kev tsim cov DNA sib txuas ntxiv (cDNA) siv tus qauv RNA. Lub enzyme siv nyob rau hauv qhov rov qab transcription yog rov qab transcriptase. Qhov no yog qhov sib txawv tseem ceeb ntawm kev hloov pauv thiab thim rov qab.
Kev txhais lus yog dab tsi?
Kev txhais lus yog suav tias yog thawj kauj ruam ntawm kev qhia gene. Cov txheej txheem no koom nrog hauv kev ua mRNA molecule los ntawm kev luam cov DNA sib lawv liag ntawm cov noob. Qhov kawg tshwm sim ntawm cov noob qhia yog ua los ntawm kev ua haujlwm molecule - ib qho protein. Hauv eukaryotes, ua ntej cov txheej txheem txhais lus pib, cov ntawv sau tseg yuav raug ua cov txheej txheem sib txawv. Cov enzyme tseem ceeb siv hauv kev sau ntawv yog RNA polymerase. Nws siv cov qauv ntawm ib leeg-stranded DNA los ua ke ib qho ntxiv mRNA strand. RNA polymerase ua haujlwm hauv 5' rau 3' kev taw qhia, ntxiv nucleotides tshiab rau 3' kawg.
Daim duab 01: Kev txhais lus
Kev txhais lus yog txheej txheem ntawm 03 kauj ruam: pib, elongation, thiab txiav tawm. Eukaryotic transcription yog me ntsis siab dua li prokaryotic transcription. Thaum pib cov kauj ruam ntawm prokaryotic transcription, RNA polymerase khi rau ib cheeb tsam tshwj xeeb ntawm cov noob, ib theem ntawm DNA hu ua tus txhawb nqa. RNA polymerase tom qab ntawd ua kom yooj yim rau kev sib cais ntawm ob txoj hlua khi rau hauv ob txoj hlua, uas muab ib qho qauv qauv rau kev sau ntawv. Thaum lub sij hawm elongation, RNA polymerase nyeem qhov sib lawv liag ntawm tib strand DNA (template strand), ntxiv nucleotides raws li complementary puag khub. Cov txheej txheem no tshwm sim los ntawm 5 'mus rau 3' kawg. Cov ntaub ntawv sau tseg yuav muaj tib cov ntaub ntawv caj ces zoo ib yam li coding strand ntawm DNA nrog ib qho kev zam, muaj lub hauv paus uracil tsis yog thymine. Ib tug terminator ib ntus tam sim no nyob rau hauv cov noob yuav xaus qhov txheej txheem. Cov ntawv sau yuav raug tshem tawm ntawm RNA polymerase thiab ncaj qha ua mRNA. Eukaryotic transcription muaj ob peb kauj ruam sib txawv thaum thawj cov ntawv sau ua ntej mRNA raug tsim. A 5 'cap thiab 'poly A' tus Tsov tus tw yog ntxiv rau pre mRNA strand. Lub mRNA ua ntej kuj tau txais cov txheej txheem hu ua splicing uas tshem tawm cov cheeb tsam tsis-coding (introns) thiab khaws cov coding cheeb tsam (exons) uas thaum kawg yuav code rau cov protein ua haujlwm.
Dab tsi yog Reverse Transcription?
Kev hloov pauv rov qab yog txheej txheem los ntawm kev sib txuas ntawm DNA sib txuas (cDNA) tshwm sim los ntawm RNA qauv. Qhov no feem ntau tshwm sim hauv cov kab mob retroviruses, tab sis kuj muaj qee yam tsis yog retroviruses xws li kab mob siab B. Kev hloov pauv rov qab tau yooj yim los ntawm qhov muaj RNA nyob ntawm DNA polymerase, feem ntau hu ua thim rov qab transcriptase. Rov qab transcriptase ntawm retroviruses yog tsim los ntawm peb qhov kev ua haujlwm biochemical: RNA nyob ntawm DNA polymerase kev ua haujlwm, ribonuclease H kev ua, thiab DNA nyob ntawm DNA polymerase kev ua. Peb cov txheej txheem txuas ntxiv yog siv los ntawm retroviruses hauv kev hloov pauv ntawm ib leeg-stranded RNA mus rau ob-stranded cDNA. Qhov ob-stranded cDNA no tuaj yeem muab tso rau hauv tus tswv tsev genome uas yuav ua rau muaj kev cuam tshuam ntev. Zoo ib yam li lwm hom DNA polymerases, thim rov qab transcriptase yog nyob ntawm cov qauv thiab primers. Lub ribonuclease H kev ua ntawm thim rov qab transcriptase yuav pab txhawb kev degradation ntawm RNA strand ib zaug thawj DNA strand yog synthesized. Tom qab ntawd cov enzyme siv cov khoom sib txuas ua ke los ua ib qho qauv tshiab uas ua rau ob txoj hlua DNA molecule. Txij li thaum rov qab transcriptase tsis muaj 3' rau 5' exonucleolytic kev ua, cov txheej txheem thim rov qab yog qhov yuam kev.
Daim duab 02: Rov qab sau dua
Dab tsi yog qhov zoo sib xws ntawm Kev Tshaj Tawm thiab Kev Hloov Rov Qab?
- Ob leeg koom nrog cov txheej txheem ntawm cov noob qhia uas ua rau tsim cov khoom lag luam gene.
- Ob txoj kev yog enzyme mediated.
- Ob txheej txheem muaj nyob rau hauv lub nucleus ntawm eukaryotes thiab cytoplasm ntawm prokaryotes.
Dab tsi yog qhov sib txawv ntawm Kev Tshaj Tawm thiab Kev Hloov Rov Qab?
Kev hloov pauv hloov pauv rov qab |
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| Kev txhais lus yog tus txheej txheem uas cov ntaub ntawv nyob rau hauv ib txoj hlua DNA tau theej rau hauv ib lub qauv tshiab ntawm tus tub txib RNA (mRNA). | Rov qab sau dua yog cov txheej txheem uas tsim cov cDNA los ntawm RNA template hauv retroviruses. |
| Enzymes koom nrog | |
| RNA polymerase koom nrog hauv kev sau. | Reverse transcriptase muaj feem cuam tshuam nrog kev hloov pauv rov qab. |
| khoom kawg | |
| Cov khoom kawg ntawm kev sau yog mRNA. | Cov khoom lag luam ntawm kev rov qab rov qab yog ua tiav DNA. |
| Function | |
| Lub luag haujlwm ntawm kev sau ntawv yog los ua ke mRNA kom muab txhais ua cov protein. | Qhov kev ua haujlwm ntawm kev hloov pauv rov qab yog los tsim cov DNA ntxiv; Cov txheej txheem no yog siv hauv vivo txhawm rau txheeb xyuas cov coding sequences ntawm DNA thiab npaj cDNA cov tsev qiv ntawv. |
Summary – Transcription vs Reverse Transcription
Kev txhais lus thiab thim rov qab yog ob txoj hauv kev uas pab txhawb cov noob caj noob ces. Transcription yog thawj theem ntawm cov noob qhia. Thaum hloov pauv, mRNA molecule yog tsim los ntawm DNA qauv. Lub enzyme koom nrog hauv qhov kev sib txuas no yog RNA polymerase. Rov qab transcription yog txheej txheem siv los ntawm retroviruses ntau dua. Thaum lub sijhawm ua haujlwm no, lub cDNA molecule yog tsim los ntawm RNA template. Retroviruses siv cov txheej txheem no los koom nrog lawv cov noob rau hauv tus tswv tsev genome. Rov qab transcriptase yog enzymes siv hauv cov txheej txheem no. Qhov no yog qhov sib txawv ntawm cov ntawv sau thiab thim rov qab.
Download PDF Version of Transcription vs Reverse Transcription
Koj tuaj yeem rub tawm PDF version ntawm kab lus no thiab siv nws rau offline hom phiaj raws li cov ntawv sau tseg. Thov rub tawm PDF version ntawm no Qhov txawv ntawm Kev Hloov Hloov thiab Rov Hloov Hloov
