Qhov Tseem Ceeb Qhov Sib Txawv - Kev Sib Tw Npuas vs Replication Fork
Replication npuas thiab replication diav rawg yog ob lub qauv tsim thaum lub sij hawm DNA replication thiab qhov sib txawv tseem ceeb ntawm Replication Bubble thiab Replication Fork yog qhov replication npuas yog qhov qhib tam sim no nyob rau hauv DNA strand thaum pib ntawm replication thaum replication diav rawg yog cov qauv tam sim no nyob rau hauv cov npuas replication uas qhia txog qhov tshwm sim tiag tiag ntawm replication.
Nyob rau hauv cov ntsiab lus ntawm molecular biology, DNA replication yog ib tug txheej txheem uas ob zoo tib yam luam ntawm DNA yog tsim los ntawm ib tug DNA molecule. Cov txheej txheem lom neeg no yog lub hauv paus ntawm kev txuas ntxiv ntawm tag nrho cov ntaub ntawv ntawm lub neej thiab kev lom neeg qub txeeg qub teg. DNA replication tshwm sim nyob rau hauv tag nrho cov kab mob nyob. Cov txheej txheem rov ua dua muaj cov txheej txheem sib txawv, cov enzymes, cov khoom siv roj ntsha, thiab cov qauv sib txuas uas tau tsim los pib rov ua dua tshiab thiab ua tiav. Cov npuas replication thiab replication diav rawg yog cov qauv uas tau tsim thaum lub sij hawm DNA replication. Ob qho tib si replication npuas thiab replication diav rawg muaj nyob rau hauv prokaryotes thiab eukaryotes.
Dab tsi yog qhov Replication Bubble?
DNA replication yog txheej txheem uas DNA molecule replicates thiab ua ib daim qauv ntawm nws tus kheej. Cov npuas replication yog suav tias yog qhov qhib uas muaj nyob rau hauv DNA strand thaum pib ntawm replication. Qhov tsim ntawm replication npuas sib txawv hauv prokaryotes thiab eukaryotes. Prokaryotes muaj ib qho ua npuas npuas thaum eukaryotes muaj ntau qhov sib txawv npuas.
Cov npuas rov ua dua tshiab muaj peev xwm loj hlob hauv ob qho kev qhia vim muaj cov khoom siv rov ua dua tshiab. Nyob rau hauv txhua replication npuas, muaj ob replication forks. Qhov no yog lub ntsiab lus uas niam txiv DNA muab ob npaug rau helix splits. Nyob rau hauv cov ntsiab lus ntawm eukaryotic kab mob, lawv muaj ib tug tseeb nucleus. eukaryotic DNA yog linear. Vim li no, qhov kev rov ua dua tshiab tshwm sim ntawm ntau qhov chaw uas ua rau muaj ntau cov npuas rov ua dua.
Kev ua haujlwm ntawm cov npuas replication tshwm sim nrog cov enzyme DNA helicase uas rhuav cov hydrogen bonds tam sim no ntawm cov nitrogenous hauv paus ntawm ob niam txiv DNA strands. Ib leeg Strand Binding Proteins yog txuas nrog cov niam txiv DNA sib cais los tiv thaiv kev hloov pauv ntawm hydrogen bonds.
Daim duab 01: Cov npuas ntawm Eukaryotic DNA
Kev tawg ntawm hydrogen bonds ntawm ob txoj hlua ua rau kev so ntawm ob lub helix thiab tseem tsim kom muaj kev sib zog ntxiv rau hauv cov molecule vim tsis muaj zog. Lub enzyme topoisomerase koom nrog hauv kev rhuav tshem cov kev sib txuas ntawm phosphodiester ntawm ob lub helix ntawm qhov chaw txuas ntxiv ntawm cov npuas replication uas txo cov kev ntxhov siab ntawm cov cheeb tsam los ntawm kev rov ua dua tam sim.
Replication Fork yog dab tsi?
Nyob rau hauv cov ntsiab lus ntawm lub voj voog ntawm tes, DNA replication tshwm sim nyob rau theem S. Cov txheej txheem pib nrog DNA sequences uas tau txhais ua ntej thiab raug hu ua replication keeb kwm. Ntawm cov cheeb tsam no, cov npuas replication yog tsim uas ua rau DNA replication. Nws tau hais yav dhau los tias txhua tus npuas replication muaj ob daim ntawv rov ua dua tshiab. Thaum DNA replication tshwm sim, replication proteins npaj rau hauv ib tug qauv uas zoo li ib tug ob-pronged diav rawg. Vim qhov tsim ntawm cov qauv, qhov no yog hu ua replication diav rawg. Cov replication proteins no tswj tag nrho cov txheej txheem ntawm DNA replication.
DNA helicase unwinds ob-stranded niam txiv DNA rau hauv ob qho tib si los ntawm kev tawg cov hydrogen bonds txuas cov nitrogenous bases ntawm ob strands. Qhov no tshwm sim nyob rau hauv pem hauv ntej ntawm replication diav rawg thiab tsim ib leeg-stranded DNA.
Lub luag haujlwm tseem ceeb ntawm kev rov ua dua rab rawg yog DNA unwinding thiab DNA synthesis. DNA synthesis los ntawm replication diav rawg yog ua tiav nrog cov enzyme DNA polymerase. DNA polymerase txuas DNA hauv paus hauv qhov tseeb raws li kev sib koom ua ke ntawm kev sib koom ua ke.
Daim duab 02: Cov Khoom Siv Tawv Rov Ua Dua
Txhawm rau tiv thaiv qhov kev cuam tshuam ntawm kev rov ua dua rab rawg, muaj cov protein tshwj xeeb hu ua replication fork tiv thaiv complex. Lub luag haujlwm tseem ceeb ntawm qhov kev ua haujlwm no yog kom rov ua kom ruaj khov yog tias qhov rov ua dua rab rawg raug kaw vim yog vim li cas thiab nws koom nrog kev sib koom tes ntawm kev sib txuas ntawm cov coj thiab lagging strands thiab tseem nyob rau hauv replication checkpoint signaling.
Dab tsi zoo sib xws ntawm Replication Bubble thiab Replication Fork?
- Ob qho tib si replication npuas thiab replication diav rawg tuaj yeem pom thaum lub sij hawm DNA replication.
- Ob lub qauv muaj ntau rau ob qho tib si prokaryotic thiab eukaryotic DNA replication.
- Ob lub qauv pab thiab ua rau DNA rov ua dua.
Dab tsi yog qhov txawv ntawm Replication Bubble thiab Replication Fork?
Replication Bubble vs Replication Fork |
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| Replication npuas txhais tau tias yog qhov qhib uas muaj nyob rau hauv DNA strand thaum pib ntawm replication. | Replication diav rawg txhais tau tias yog cov qauv uas muaj nyob rau hauv cov npuas replication uas qhia txog qhov tshwm sim ntawm replication. |
| Prokaryotic Replication | |
| Ib lub npuas rov ua dua. | Ib daim ntawv sib dhos yog tsim. |
| Eukaryotic Replication | |
| Ntau cov npuas rov ua dua yog tsim. | Ntau daim ntawv rov ua dua tshiab tau tsim. |
Summary – Replication Bubble vs Replication Fork
DNA replication yog txheej txheem uas niam txiv DNA strand muab ob daim ntawv luam ntawm nws tus kheej. Cov txheej txheem rov ua dua muaj cov khoom sib txawv. Replication npuas yog qhov qhib ntawm DNA strand qhov chaw pib ntawm replication tshwm sim. Hauv eukaryotes, ntau cov npuas replication muaj tshwm sim thaum nyob rau hauv prokaryotes tsuas yog ib zaug xwb replication npuas. Txhua tus npuas replication muaj ob daim ntawv rov ua dua tshiab. Ib rab diav rawg replication txhais tau tias yog ib txheej ntawm replication proteins ceeb toom nyob rau hauv ib tug ob-pronged diav rawg uas lees paub qhov pib ntawm tus txheej txheem replication. Lub replication diav rawg kev tiv thaiv complex yog tam sim no los restabilize yog hais tias tus replication diav rawg yog stalled. Prokaryotes muaj ib tug tib replication diav rawg complex thaum nyob rau hauv eukaryotes, muaj ntau tus xov tooj ntawm diav rawg. Qhov no yog qhov sib txawv ntawm cov npuas replication thiab replication fork.
