Qhov sib txawv tseem ceeb ntawm mRNA thiab tRNA yog tias mRNA nqa cov ntaub ntawv keeb kwm ntawm cov noob los tsim cov protein thaum lub tRNA paub txog peb lub nucleotide mRNA sequences los yog codons thiab nqa cov amino acids rau ribosomes raws li cov codons. mRNA.
Nucleic acids xws li DNA thiab RNA yog macromolecules tsim ntawm nucleotides. Deoxyribonucleic Acid (DNA) yog lub luag haujlwm rau nqa cov ntaub ntawv caj ces los ntawm ib tiam dhau ib tiam thaum Ribonucleic Acid (RNA) feem ntau koom nrog hauv cov protein synthesis. Txawm hais tias DNA yog cov khoom tseem ceeb ntawm cov kab mob uas muaj sia nyob, qee cov kab mob muaj RNA genomes. Ribonucleotides yog cov monomers ntawm RNA. Ribonucleotide muaj ribose qab zib, nitrogenous puag thiab phosphate pawg. Nitrogenous bases yog ob hom xws li purines thiab pyrimidines. Lub hauv paus purines yog Adenine (A) thiab Guanine (G), thaum pyrimidines yog Cytosine (C) thiab Uracil (U). Feem ntau, RNA muaj nyob hauv cytoplasm. Muaj peb chav kawm ntawm RNA: tub txib RNA (mRNA), hloov RNA (tRNA) thiab ribosomal RNA (rRNA) thiab peb chav kawm no ua haujlwm sib koom tes hauv kev sib txuas ntawm cov protein.
mRNA yog dab tsi?
Messenger RNA (mRNA) yog ib qho ntawm peb hom RNA uas nqa cov ntaub ntawv genetic encoded hauv cov noob los tsim cov protein. Li no, mRNA ib ntus zoo ib yam li coding sequence ntawm cov noob. Thaum lub sij hawm gene qhia, ib lub noob tau txais kev hloov pauv thiab ua rau mRNA molecule. Thaum lub sij hawm thib ob ntawm gene qhia; hauv kev txhais lus, mRNA yog nyeem raws li triplet codons. Cov kab mob caj ces ntawm DNA qhia cov amino acid tus neeg sib tham rau txhua tus triplet codons. Hauv eukaryotes, ib qho mRNA yog coded rau ib leeg polypeptide saw thaum, nyob rau hauv prokaryotes, ob peb polypeptide chains yuav coded los ntawm ib tug tib mRNA strand.
Figure 01: mRNA
Feem ntau mRNA molecules muaj lub neej luv luv thiab tus nqi hloov pauv siab. Yog li ntawd, lawv tuaj yeem ua ke ntau dua thiab ntau dua los ntawm tib qhov ncab ntawm cov qauv DNA. Hauv lub neej luv luv no, nws tau ua tiav, kho thiab thauj ua ntej kev txhais lus hauv eukaryotes. Thaum lub sij hawm ua, ntau yam tshwm sim xws li 5' cap ntxiv, splicing, kho, thiab polyadenylation. Hauv prokaryotes, kev ua haujlwm tsis tshwm sim.
Nyob hauv eukaryotes, kev txhais lus thiab kev sau ntawv tshwm sim nyob rau hauv ntau qhov chaw, yog li lawv yuav tsum tau thauj ntau heev. Yog li, mRNA molecule taug kev los ntawm lub nucleus mus rau cytoplasm.
TRNA yog dab tsi?
Lub luag haujlwm tseem ceeb ntawm kev hloov pauv RNA lossis tRNA yog nqa cov amino acids mus rau ribosomes thiab cuam tshuam nrog mRNA hauv kev txhais cov protein synthesis. Cov tRNAs no muaj 70-90 nucleotides. Tag nrho cov tRNA molecules matured muaj ib tug thib ob qauv uas muaj ob peb hairpin loops. Thaum kawg, tRNA muaj anticodon uas khi nrog mRNA.
Figure 02: tRNA
Raws li qhov kev txiav txim ntawm cov amino acids uas tau hais hauv mRNA ib ntus, cov amino acids koom nrog ib leeg hauv kev sib raug zoo. Muaj tsawg kawg yog ib hom tRNA rau txhua tus amino acid. Vim li ntawd, ib lub cell muaj tRNA ntau. Cov tRNAs no tau tsim nyob rau hauv lub precursor ob leeg eukaryotic thiab prokaryotic hlwb. Kev ua tRNA suav nrog kev tshem tawm cov thawj coj luv luv los ntawm 5' kawg, qhov sib ntxiv ntawm CCA es tsis txhob ntawm ob lub nucleotides ntawm 3' kawg, tshuaj hloov kho ntawm qee lub hauv paus thiab kev txiav tawm ntawm ib qho intron.
Qhov Zoo sib xws ntawm mRNA thiab tRNA yog dab tsi?
- mRNA thiab tRNA yog ob hom RNA tam sim no hauv cov kab mob nyob.
- Ob leeg yog qhov tseem ceeb rau kev tsim cov protein ntawm cov cell.
- Tsis tas li, ob qho tib si yog cov polymers ntawm ribonucleotides.
- Thiab, ob qho tib si ib leeg.
- Tsis tas li ntawd, lawv nyob hauv cytoplasm.
- Dhau li ntawm, txawm tias lawv ua haujlwm txawv, lawv muaj kev koom tes hauv kev sib txuas ntawm cov protein.
Qhov txawv ntawm mRNA thiab tRNA yog dab tsi?
Raws li qhov tshwm sim ntawm cov noob qhia, mRNA yog muab los ntawm DNA qauv. Yog li ntawd, nws nqa cov ntaub ntawv keeb kwm ntawm cov noob los tsim cov protein. Ntawm qhov tod tes, tRNA yog qhov tseem ceeb hauv kev coj cov amino acids mus rau ribosome raws li cov codons teev nyob rau hauv mRNA ib ntus. Yog li, qhov sib txawv tseem ceeb ntawm mRNA thiab tRNA yog qhov ua haujlwm saum toj no ntawm txhua lub molecule. Tsis tas li ntawd, muaj qhov sib txawv ntawm mRNA thiab tRNA.mRNA yog ib qho kev nthuav tawm tawm molecule thaum tRNA yog 3-D qauv tsim los ntawm ntau lub voj voos plaub hau.
Ntxiv mus, mRNA muaj codons thaum tRNA muaj anticodons. Peb tuaj yeem xav txog qhov no kuj yog qhov sib txawv ntawm mRNA thiab tRNA. Tsis tas li ntawd, mRNA ntu ntev nyob ntawm cov noob ib ntus thaum tRNA rages qhov ntev ntawm 76 txog 90. Li no kuj yog qhov txawv ntawm mRNA thiab tRNA. Feem ntau, ib lub xovtooj muaj tRNA ntau dua li mRNA.
Cov duab hauv qab no qhia ntau qhov tseeb ntawm qhov sib txawv ntawm mRNA thiab tRNA.
Summary – mRNA vs tRNA
Ntawm peb hom RNA, mRNA thiab tRNA yog ob hom. Ob qho tib si yog qhov tseem ceeb rau kev tsim cov protein ntau hauv cov cell. Txawm li cas los xij, qhov sib txawv tseem ceeb ntawm mRNA thiab tRNA yog lawv txoj haujlwm.mRNA nqa cov ntaub ntawv keeb kwm ntawm cov noob los tsim cov protein nyob rau hauv peb tsab ntawv code thaum lub tRNA coj cov amino acids rau ribosome raws li cov codons teev nyob rau hauv mRNA ib ntus. mRNA yog synthesized nyob rau hauv lub nucleus thiab thauj mus rau lub cytoplasm. Ntawm qhov tod tes, tRNA muaj nyob hauv cytoplasm. mRNA ib qho tRNA ua haujlwm sib koom tes thaum lub sijhawm sib txuas ntawm cov saw hlau polypeptide hauv ribosome. Yog li, qhov no qhia txog qhov sib txawv ntawm mRNA thiab tRNA.
