Qhov Tseem Ceeb Qhov Sib Txawv - Linear vs Circular DNA
Deoxyribose nucleic acid (DNA) yog daim ntawv tseem ceeb li cas cov kab mob feem ntau khaws lawv cov ntaub ntawv caj ces. Yog li ntawd, cov qauv thiab kev ua haujlwm ntawm DNA muaj txiaj ntsig zoo heev. DNA tuaj yeem pom nyob rau hauv ob hom; daim ntawv linear thiab daim ntawv ncig. Linear DNA yog daim ntawv ntawm DNA tam sim no nyob rau hauv lub eukaryotic nucleus thiab yog tsim los ntawm ob tug dawb xaus. Circular DNA feem ntau pom nyob rau hauv prokaryotes, whereas mitochondria, chloroplast thiab plasmids kuj muaj cov DNA ncig. Circular DNA muaj nyob rau hauv cytoplasm ntawm prokaryotic cell, nyob rau hauv mitochondria los yog nyob rau hauv lub chloroplast. Qhov sib txawv tseem ceeb ntawm cov kab thiab voj DNA yog cov qauv tsim ntawm cov molecule. Linear DNA tau txais qhov qhib kev teeb tsa nrog ob qhov kawg dawb, thaum lub voj voog DNA tau txais kev sib raug zoo uas tsis muaj qhov kawg.
Dab tsi yog Linear?
Linear DNA muaj nyob rau hauv eukaryotic genomes nyob rau hauv lub cell nucleus. Lub linear DNA yog tsim los ntawm ob qhov kawg dawb, thiab yog li nws yog ib qho qhib qauv. Linear DNA tuaj yeem raug cais tawm thiab sib cais ntawm agarose gel media, txawm hais tias vim yog qhov loj ntawm DNA, smear yuav raug pom ntawm lub gel. Txhawm rau cais thiab cais cov seem xav tau ntawm cov kab DNA, cov DNA tuaj yeem raug txiav siv kev txwv endonucleases thiab tom qab ntawd pom ntawm cov gel khiav.
Daim duab 01: Linear DNA
Cov txheej txheem rov ua dua ntawm cov kab DNA yog txheej txheem nyuaj vim nws koom nrog ntau cov txheej txheem. Lub replication tshwm sim nyob rau hauv ib tug bidirectional yam, qhov twg ob replication forks yog tsim. Linear DNA tej zaum yuav muaj ntau lub hauv paus chiv keeb ntawm qhov chaw replication, vim hais tias linear DNA yog ntau ntev thiab complex. Cov txheej txheem rov ua dua txuas ntxiv mus txog thaum qhov kev txiav tawm yuav tshwm sim thaum daws qhov teeb meem xaus qhov kawg raws li cov kab DNA yog tsim los ntawm telomeric sequences.
DNA yog dab tsi?
Circular DNA yog ib qho kev sib koom ua ke ntawm DNA uas nws tau txais cov qauv kaw. Lub voj voog DNA tsis muaj qhov sib txawv. Lub voj DNA muaj nyob rau hauv yuav luag tag nrho cov prokaryotes nrog qee qhov kev zam, hauv mitochondria thiab chloroplast ntawm eukaryotes thiab hauv plasmids. Circular DNA yog nyob rau hauv lub cell cytoplasm ntawm cov prokaryotes. Circular DNA tuaj yeem muaj nyob hauv ntau hom ntawv suav nrog cov ntawv supercoiled thiab nicked ncig DNA daim ntawv. Thaum lub voj DNA sib cais thiab sib cais los ntawm agarose gel electrophoresis, cov ntaub ntawv sib txawv ntawm cov DNA ncig tuaj yeem pom cov khoom sib txawv ntawm cov gel.
Plasmid DNA tseem hu ua extrachromosomal ncig DNA tam sim no hauv qee cov kab mob tau pom tias muaj txiaj ntsig zoo hauv kev ua liaj ua teb molecular biology thiab genetic engineering. Plasmids yog kev lag luam ua ke thiab siv los ua vectors hauv molecular cloning. Qee qhov piv txwv ntawm plasmid vectors yog pBR322, pUC18.
Daim duab 02: Circular DNA
Kev rov ua dua ntawm cov DNA ncig yog qhov sib txawv heev hauv kev sib piv rau cov kab DNA. Thaum lub sij hawm replication txheej txheem, tsuas yog ib lub hauv paus ntawm replication yog tam sim no, thiab vim nws ncig xwm, replication yuav tshwm sim nyob rau hauv ib tug unidirectional yam nrog tsim ntawm ib tug replication diav rawg.
Dab tsi zoo sib xws ntawm Kab thiab voj DNA?
- Ob txoj kab thiab voj DNA yog tsim los ntawm Deoxyribose nucleic acids uas muaj adenine, guanine, cytosine thiab thymine nucleotides.
- Ob txoj kab thiab voj DNA muaj ob txoj hlua khi helical.
- Ob txoj kab thiab voj DNA txiav txim siab cov yam ntxwv ntawm cov kab mob.
- Ob txoj kab thiab voj DNA tuaj yeem sib cais siv agarose gel electrophoresis txoj kev.
- Ob daim ntawv DNA tuaj yeem nthuav dav siv cov txheej txheem molecular xws li Polymerase Chain Reaction.
- Ob txoj kab thiab voj DNA feem ntau yog siv rau hauv DNA raws li kev kuaj mob thiab hauv cov ntawv thov hauv genetic engineering.
Dab tsi yog qhov txawv ntawm Kab thiab voj DNA?
Kab thiab voj DNA |
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| Linear DNA yog daim ntawv ntawm DNA tam sim no nyob rau hauv lub eukaryotic nucleus thiab yog tsim los ntawm ob lub dawb xaus. | Circular DNA yog DNA uas muaj qhov sib txuam kaw thiab pom nyob rau hauv cytoplasm ntawm prokaryotic cell, mitochondria lossis chloroplast. |
| faib | |
| Linear DNA muaj nyob rau hauv lub nucleus ntawm eukaryotes. | Zoo DNA muaj nyob hauv cytoplasm. |
| Replication | |
| Kev rov ua dua ntawm cov kab DNA muaj ntau lub hauv paus ntawm kev rov ua dua, thiab nws yog txheej txheem nyuaj. | Kev rov ua dua ntawm cov DNA ncig muaj tib lub hauv paus ntawm kev rov ua dua, thiab nws yog txheej txheem yooj yim. |
Summary – Linear vs Circular DNA
Kab thiab voj DNA yog ob daim ntawv tseem ceeb npaum li cas DNA tau muab faib rau hauv eukaryotic thiab prokaryotic hlwb feem. Linear DNA muaj nyob rau hauv lub nucleus ntawm eukaryotes thiab yog tsim los ntawm ob tug dawb xaus thiab complex sequences. Circular DNA muaj nyob rau hauv prokaryotes thiab kuj nyob rau hauv mitochondrial thiab chloroplast DNA uas muaj ib tug kaw conformation. Ob qho tib si DNA tau siv dav hauv kev tshawb fawb txog molecular biological thiab genetic engineering. Qhov no yog qhov txawv ntawm kab thiab voj DNA.
Download the PDF of Linear vs Circular DNA
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 rub tawm PDF version ntawm no: Qhov Sib txawv Ntawm Kab thiab Circular DNA
