Qhov sib txawv tseem ceeb ntawm introns thiab exons yog tias introns yog cov tsis-coding sequences ntawm ib tug noob thaum exons yog coding sequences. Li no, introns tsis tshwm sim hauv mRNA molecules paub tab thaum exons sib sau ua tus kawg RNA molecule.
Introns thiab exons feem ntau siv cov ntsiab lus hauv thaj tsam ntawm molecular biology, tab sis thaum ib tus neeg pib paub txog cov ntsiab lus no, tsis meej pem yuav tshwm sim vim ob qho no yog nucleotide sequences ntawm noob.
Dab tsi yog Introns
Introns yog cov kab ke ntawm nucleotides tam sim no hauv cov noob ntawm exons. Cov nucleotide sequences tsis code rau cov proteins, thiab qhov ntawd txhais tau hais tias introns tsis tseem ceeb tam sim ntawd rau cov txheej txheem ntawm cov protein synthesis. Thaum tus tub txib RNA (mRNA) strand yog tsim los ntawm kev hloov pauv ntawm DNA ntawm cov noob, cov nucleotide sib lawv liag ntawm introns raug cais tawm. Tsis tas li ntawd, qhov kev cais tawm ntawm cov kab ke intron los ntawm mRNA strand tshwm sim los ntawm cov txheej txheem hu ua RNA splicing; Nws tuaj yeem yog los ntawm cis-spling thaum tsuas muaj ib qho intron koom nrog cov noob, trans-spling tshwm sim thaum muaj ob lossis ntau qhov introns cuam tshuam nrog cov noob.
Ib mRNA paub tab, uas yog npaj rau code rau cov protein, yog tsim tom qab tshem tawm cov introns los ntawm strand. Txij li thaum ob qho tib si DNA thiab RNA muaj cov tsis-coding sequences, lub sij hawm intron tuaj yeem xa mus rau cov tsis-coding nucleotide sequences ntawm DNA thiab lawv cov sequences nyob rau hauv RNA.
Nws tseem ceeb heev kom pom tias ribosomal RNA (rRNA) thiab hloov RNA (tRNA) muaj cov noob nrog introns, tab sis cov no raug tshem tawm thaum cov noob qhia. Hauv lwm lo lus, introns mus dhau ntawm kev sau, tab sis tsis yog los ntawm kev txhais lus. Yog li ntawd, cov no yog hu ua untranslated sequences ntawm DNA. Kev ua haujlwm tam sim ntawm introns yog qhov tsis meej me ntsis, tab sis nws ntseeg tau tias cov no yog qhov tseem ceeb rau kev tsim kom muaj ntau haiv neeg, tseem muaj feem cuam tshuam cov proteins los ntawm ib lub noob. Tsis tas li ntawd, intron-mediated txhim kho ntawm cov noob qhia tau raug lees paub tias yog lwm txoj haujlwm tseem ceeb ntawm introns.
Dab tsi yog Exons
Exons yog cov nucleotide sequences ntawm cov noob uas tau qhia thiab pom ntawm ob sab ntawm ib qho intron. Hauv cov ntsiab lus yooj yim, nws tuaj yeem hais tau tias exons yeej ntaus hauv av hauv kev qhia cov noob lossis hauv cov protein synthesis. Tom qab tshem tawm cov tsis-coding sequences los ntawm pre mRNA, mRNA mRNA molecule mature muaj tsuas yog exon sequences. Tom qab ntawd cov nucleotide ib ntus ntawm mRNAs paub tab yog hloov mus rau hauv cov amino acid ib ntus ntawm cov protein tshwj xeeb.
Daim duab 01: Introns thiab Exons
Yuav luag txhua cov noob muaj qhov pib nucleotide ib ntus uas txawv nws li cov noob los ntawm lub ntsiab DNA lossis RNA strand, uas yog hu ua Open Reading Frame (ORF); ob lub ORFs cim qhov kawg ntawm cov noob nyob rau hauv cov exons nyob. Txawm li cas los xij, muaj cov xwm txheej uas exons tsis qhia hauv cov noob. Muaj cov xwm txheej uas intron sequences cuam tshuam nrog exon ua rau kev hloov pauv, thiab cov txheej txheem no hu ua exonization.
Dab tsi zoo sib xws ntawm Introns thiab Exons?
- Introns thiab Exons yog nucleotide sequences ntawm noob.
- Ob qho tib si sib txuas ua ntej mRNA.
- Lawv yog cov kab mob intragenic.
- Lawv muaj nyob hauv DNA thiab RNA.
- Ob leeg muaj nyob hauv eukaryotes.
Qhov txawv ntawm Introns thiab Exons yog dab tsi?
Introns vs Exons |
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| Introns yog cov nucleotide sequences ntawm ib cov noob uas tsis-coding. | Exons yog cov txheej txheem coding ntawm cov noob uas xav tau los tsim mRNA paub tab |
| Thaum RNA Splicing | |
| Nyob zoo | Koom ua ke tsim mRNA mRNA |
| Mature mRNA | |
| Txhob pab tsim kom muaj mRNA mRNA | Mature mRNA cov ntaub ntawv los ntawm tag nrho cov txheej txheem ntawm cov noob |
| Nature of Sequence | |
| Tsawg khaws cia ib ntus dhau sijhawm | Kev txuag ntau dhau sijhawm ntawm hom |
| Muaj nyob hauv qhov kawg RNA molecule | |
| Tsis txhob tshwm sim hauv RNA molecule kawg | Tshuaj nyob rau hauv qhov kawg RNA molecule vim lawv muaj cov noob caj noob ces |
| Ib qho tseem ceeb hauv Protein Synthesis | |
| Tsis tseem ceeb tam sim rau kev tsim cov protein vim lawv tsis yog coding | Coding sequences yog qhov tseem ceeb tshaj plaws rau kev tsim cov protein. |
| Kev muaj nyob hauv Prokaryotes thiab Eukaryotes | |
| Tsis muaj nyob rau hauv prokaryotes | Tam sim no hauv ob qho tib si prokaryotes thiab eukaryotes |
Summary – Introns vs Extrons
A noob muaj ob qho tib si coding thiab tsis-coding sequences. Tsis-coding sequences tsis koom nrog cov protein synthesis. Lawv yog introns. Coding sequences dais cov noob caj noob ces ntawm cov protein. Lawv yog exons. Zuag qhia tag nrho, qhov no yog qhov sib txawv tseem ceeb ntawm introns thiab extrons.
