Qhov Tseem Ceeb Qhov txawv - Monocistronic vs Polycistronic mRNA
Lub mRNA molecule nqa cov ntaub ntawv caj ces los tsim cov protein. Nyob rau hauv tag nrho cov kab mob nyob, lub cell tag nrho cov mRNA tau muab txhais ua cov proteins los ntawm cov txheej txheem hu ua kev txhais lus. Muaj ntau qhov sib txawv ntawm prokaryotic thiab eukaryotic mRNA molecules. Lub eukaryotic mRNA yog synthesized raws li ib tug loj precursor molecule nyob rau hauv lub nucleus uas tom qab hloov. Lub eukaryotic mRNA encodes tsuas yog rau ib qho protein thiab invariably sawv cev rau ib lub noob. Yog li ntawd, lawv tau hais tias yog monocistronic. Lub prokaryotic mRNA nqa cov sequences uas encode ntau cov proteins. Li no, lawv raug hu ua polycistronic mRNA. Tshwj xeeb tshaj yog, nyob rau hauv ib tug polycistronic mRNA, ib tug tib mRNA yog transcribed los ntawm ib pawg ntawm cov noob uas nyob ib sab. Cov pab pawg no raug hu ua operons xws li; Lac operon, galactose operon thiab tryptophan operon. Qhov sib txawv tseem ceeb ntawm Monocistronic thiab Polycistronic mRNA yog tias monocistronic mRNA muaj cov ntaub ntawv caj ces ntawm ib qho protein thaum lub polycistronic mRNA nqa cov ntaub ntawv caj ces ntawm ntau cov noob uas tau muab txhais ua ntau cov proteins.
Monocistronic mRNA yog dab tsi?
The mRNA yog lub npe hu ua monocistronic vim nws nqa cov ntaub ntawv caj ces los txhais ib qho protein xwb. Eukaryotic mRNA yog monocistronic, thiab nws muaj cov ntaub ntawv genetic codes tsuas yog rau ib qho protein xwb. Yog li lawv tsim ib qho protein tom qab kev txhais lus. Eukaryotic mRNAs yog invariably monocistronic nyob rau hauv cov xwm.
Daim duab 01: Monocistronic mRNA
Lub monocistronic mRNA tsuas muaj ib qho qhib kev nyeem ntawv nkaus xwb hu ua "ORF." Qhov qhib kev nyeem ntawv no sib raug rau ib qho kev hloov pauv ntawm cov noob caj noob ces. Lub eukaryotic mRNA molecule yog synthesized nyob rau hauv lub nucleus raws li ib tug loj precursor. Tom qab ntawd, kev txo qhov loj me yuav tshwm sim nrog rau ntau qhov kev hloov kho tseem ceeb. Tom qab ntawd, nws raug xa mus rau cytoplasm. Yog li, nws yog synthesized thiab qhia nyob rau hauv txawv cellular compartments. Cov eukaryotic mRNAs yog qhov ruaj khov heev vim muaj kev hloov pauv tom qab hloov pauv. Lawv ib nrab lub neej tuaj yeem yog ob peb teev lossis ntev dua nyob ntawm qhov ua haujlwm tshwj xeeb.
Polycistronic mRNA yog dab tsi?
Lub polycistronic mRNA muaj cov codons ntau tshaj ib cistron. Lub polycistronic mRNA tau sau los ntawm ntau tshaj ib lub noob (cistron) thiab muaj ntau yam pib thiab txiav tawm codons. Thiab tseem nws codes rau ntau tshaj ib tug protein. Lub polycistronic mRNA nqa ntau qhov qhib nyeem ntawv (ORFs). Txhua tus ntawm lawv tau muab txhais ua cov saw hlau polypeptide. Tshwj xeeb tshaj yog nyob rau hauv lub polycistronic mRNA, ib tug tib mRNA yog transcribed los ntawm ib pawg ntawm cov noob uas nyob ib sab.
Daim duab 02: Polycistronic mRNA
Cov prokaryotic mRNAs tau hais tias yog polycistronic. Nyob rau tib lub sijhawm, cov kab mob mRNA tsis ruaj khov, thiab lawv degrade zoo tom qab kev txhais lus. Cov kab mob thiab archaea muaj polycistronic mRNA hauv lawv cov hlwb. Cov polypeptides uas yog tsim los ntawm polycistronic mRNA muaj cov haujlwm muaj feem xyuam. Lawv coding sequences yog tswj ua ke los ntawm ib cheeb tsam tswj. Lub cheeb tsam tswj hwm no muaj tus txhawb nqa thiab tus neeg ua haujlwm. Cov mRNAs uas yog dicistronic los yog bicistronic (encodes rau ob lub proteins) kuj categorized nyob rau hauv polycistronic mRNAs.
Dab tsi yog qhov zoo sib xws ntawm Monocistronic thiab Polycistronic mRNA?
- Ob leeg nqa cov ntaub ntawv genetic.
- ob leeg muaj peev xwm tsim tau cov protein.
- Ob leeg muaj uracil (U) nucleotide es tsis txhob thiamin (T) nucleotide.
- Ob mRNAs yog cov tub txib mRNA hom uas tseem ceeb heev rau cellular metabolism thiab ua haujlwm.
Qhov txawv ntawm Monocistronic thiab Polycistronic mRNA yog dab tsi?
Monocistronic vs Polycistronic mRNA |
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| Monocistronic mRNA tau hais tias yog monocistronic vim nws muaj cov ntaub ntawv caj ces ntawm ib qho protein. | Polycistronic mRNA tau hais tias yog polycistronic raws li nws nqa cov ntaub ntawv caj ces ntawm ntau cov noob uas tau muab txhais ua ntau cov protein. |
| Tus lej Proteins Coding | |
| Monocistronic mRNA yog coding rau ib qho protein xwb. | Polycistronic mRNA yog coding rau ntau tshaj ib cov protein. |
| Number of Initiation and Termination Condons | |
| Monocistronic mRNA tau sau los ntawm ib lub noob (cistron) thiab muaj ib qho pib codon thiab ib qho kev txiav tawm codon. | Polycistronic mRNA tau sau los ntawm ntau dua ib lub noob (cistron) thiab muaj ntau npaum li qhov pib thiab txiav tawm codons. |
| Muaj Eukaryotic thiab Prokaryotic | |
| Monocistronic mRNA nthuav tawm hauv cov kab mob eukaryotic zoo li tib neeg. | Polycistronic mRNA nthuav tawm hauv cov kab mob prokaryotic xws li kab mob thiab archaea. |
| Post-Transcriptional | |
| Monocistronic mRNA xav tau kev hloov pauv hloov pauv. | Polycistronic mRNA tsis xav tau kev hloov pauv tom qab |
| Monocistronic mRNA ruaj khov vim muaj kev hloov pauv tom qab hloov pauv thiab muaj kev ua neej ntau dua. | Polycistronic mRNA tsis ruaj khov vim tsis muaj kev hloov pauv tom qab hloov pauv thiab muaj lub neej luv dua. |
| Number of Open Reading Frame (ORF) | |
| Monocistronic mRNA muaj ib qho qhib nyeem ntawv (ORF). | Polycistronic mRNA tab tom nqa ntau qhov qhib kev nyeem ntawv (ORFs). |
Summary – Monocistronic vs Polycistronic mRNA
Tus tub txib mRNA yog ib qho tseem ceeb heev RNA molecule uas nqa cov ntaub ntawv caj ces uas tuaj yeem tsim cov saw polypeptide lossis cov protein. Raws li txoj kev xav ntawm lub hauv paus dogma tau thov los ntawm Watson thiab Crick, mRNA paub tab tau muab txhais ua cov protein tom qab uas muaj cov haujlwm tshwj xeeb. Cov proteins no tswj cov cellular metabolism thiab lwm yam haujlwm. Eukaryotic mRNA molecule yog monocistronic vim muaj cov txheej txheem coding tsuas yog rau ib leeg polypeptide. Cov neeg prokaryotic zoo li cov kab mob thiab archaea muaj polycistronic mRNA. Cov mRNA no muaj cov ntawv sau tseg ntawm ntau lub noob ntawm ib qho txheej txheem metabolic. Qhov no yog qhov txawv ntawm monocistronic thiab polycistronic mRNA.
Download the PDF Version of Monocistronic vs Polycistronic mRNA
Koj tuaj yeem rub tawm PDF version ntawm kab lus no thiab siv nws rau offline hom phiaj raws li daim ntawv ceeb toom. Thov download PDF version ntawm no Qhov txawv Ntawm Monocistronic thiab Polycistronic mRNA
