Qhov sib txawv tseem ceeb ntawm hnRNA thiab mRNA yog tias hnRNA yog qhov tsis tau ua tiav ntxov mRNA cov ntawv sau tseg uas muaj cov ntaub ntawv thaum mRNA yog cov txheej txheem RNA uas tsis muaj introns.
Muaj ntau hom RNA, thiab hnRNA thiab mRNA yog ob hom ntawm lawv. Heterogeneous nuclear RNA, tseem hu ua pre-mRNA, yog ib hom ntawm cov ntaub ntawv tseem ceeb uas tsim nyob rau hauv lub nucleus. Thaum ua ntej-mRNA tau tsim, nws tau ua tiav tom qab hloov pauv mus rau hauv mRNA ua haujlwm, uas tuaj yeem muab txhais ua cov protein hauv cytoplasm. Yog li ntawd, hnRNA yog synthesized los ntawm ib tug DNA qauv, thiab nws yog ib tug tshiab tsim RNA ua ntej ua. mRNA yog RNA ib ntus uas nqa cov ntaub ntawv caj ces los tsim cov protein. Nws yog ib daim ntawv ntawm RNA tom qab ua tiav. Ntxiv mus, mRNA nqa caj ces codons los ntawm DNA nyob rau hauv lub nucleus mus rau lub ribosomes rau cov protein synthesis.
hnRNA yog dab tsi?
Heterogeneous nuclear RNA lossis pre-mRNA yog RNA tshiab tsim los ntawm cov qauv DNA strand. Nws yog ib daim ntawv ntawm unmodified RNA. Yog li ntawd, nws yog ib hom RNA ua ntej ua. hnRNA sawv cev rau ntau hom thiab ntau thiab tsawg ntawm RNA pom nyob rau hauv lub nucleus. Feem ntau ntawm hnRNA ua haujlwm ua ntej rau mRNA. Thaum ua tiav, hnRNA nkag mus rau cov txheej txheem splicing thiab dhau los ua mRNA hauv cytoplasm. hnRNA kuj tseem tuaj yeem suav nrog qee qhov RNA nuclear uas tsis dhau los ua cytoplasmic mRNA.
Daim duab 01: hnRNA lossis Pre-mRNA
RNA polymerase yog cov enzyme uas catalyzes theej DNA rau hauv hnRNA hauv lub nucleus. Tom qab ntawd hnRNA tau ua tiav hauv lub nucleus thiab thauj mus rau cytoplasm. Los ntawm cov txheej txheem splicing, tag nrho cov introns raug tshem tawm ntawm hnRNA. Tom qab ntawd ib tug poly-A tail ntxiv rau 3′ kawg, thiab 5′ cap ntxiv rau 5′ kawg ntawm RNA.
mRNA yog dab tsi?
mRNA lossis tus xa xov RNA yog ib qho RNA ib ntus uas muaj cov ntaub ntawv caj ces ntawm cov noob los tsim cov protein. Nws yog ib daim ntawv ntawm RNA tom qab ua tiav. Yog li ntawd, nws tsuas muaj cov exons ntawm cov noob. mRNA yog muab los ntawm pre-mRNA, uas yog thawj cov ntawv sau tseg. Thaum ua tiav, mRNA tawm ntawm lub nucleus thiab mus txog ribosome hauv cytoplasm txhawm rau txhais thiab tsim cov protein. Ribosomes nyeem nucleotide triplets (codons) ntawm mRNA thiab ntxiv cov amino acids sib xws raws li cov codons. Ib yam li ntawd, ribosomes tsim cov amino acids ib ntus los ntawm mRNAs thaum lub sijhawm txhais lus.
Daim duab 02: mRNA
Kev ua thiab thauj ntawm mRNA txawv ntawm eukaryotes thiab prokaryotes. Eukaryotic mRNA yuav tsum tau ua ntau yam thiab thauj thaum prokaryotic mRNA tsis. Prokaryotic mRNA synthesis tshwm sim nyob rau hauv lub cytoplasm nws tus kheej, thiab ib zaug ua, nws yog tam sim ntawd npaj mus undergo kev txhais lus tsis ua.
Qhov Zoo sib xws Ntawm hnRNA thiab mRNA yog dab tsi?
- hnRNA thiab mRNA yog ob hom RNA pom hauv hlwb.
- hnRNA muaj mRNA precursors.
- Qhov tseeb, feem ntau ntawm hnRNA tau ua tiav rau hauv mRNA.
- Ob hnRNA thiab mRNA yog ib leeg-stranded RNA.
- Lawv xav tau rau kev sib txuas ntawm cov protein hauv hlwb.
Qhov txawv ntawm hnRNA thiab mRNA yog dab tsi?
Qhov sib txawv tseem ceeb ntawm hnRNA thiab mRNA yog tias hnRNA yog RNA tshiab ua ntej ua haujlwm, thaum mRNA yog RNA tom qab ua tiav. Tsis tas li, hnRNA tau muab ncaj qha los ntawm DNA qauv los ntawm RNA polymerase thaum mRNA yog muab los ntawm hnRNA.
Tsis tas li ntawd, hnRNA tau hla kev sib txuas thiab capping. Tab sis, mRNA tsis raug rau splicing lossis capping; nws txhais ua cov protein. Dhau li, lwm qhov sib txawv ntawm hnRNA thiab mRNA yog tias hnRNA muaj cov introns, thaum mRNA tsis muaj introns.
Summary – hnRNA vs mRNA
hnRNA yog tus tsim tshiab RNA los ntawm DNA qauv. Nws yog hom tsis hloov pauv RNA. Feem ntau ntawm hnRNA tau ua tiav thiab dhau los ua mRNA. mRNA yog ib leeg-stranded RNA tom qab ua tiav. Nws muaj cov noob caj noob ces codons los tsim cov protein tshwj xeeb. Yog li ntawd, mRNA puag ib theem zuj zus yog ntxiv rau ib ntu ntawm cov noob. mRNA tsis muaj introns. Nws muaj exons. Yog li, qhov no qhia txog qhov sib txawv ntawm hnRNA thiab mRNA.
