Qhov sib txawv tseem ceeb ntawm helicase thiab topoisomerase yog tias helicase yog ib qho enzyme uas cais ob txoj kab sib txuas ntawm DNA los ntawm kev rhuav tshem hydrogen bonds ntawm lub hauv paus ntawm ob strands thaum topoisomerase yog ib qho enzyme uas tshem tawm qhov zoo thiab tsis zoo supercoils tsim thaum lub sij hawm unwinding. txheej txheem ntawm DNA los ntawm kev txiav thiab rov ua dua ib lossis ob qho tib si ntawm DNA duplex.
DNA yog ob lub helix. Nws muaj nyob rau hauv ob qho kev sib txuas ua ke sib txuas ua ke ntawm hydrogen bonds. DNA replication, transcription thiab DNA kho yuav tsum tau muab ob strands sib cais los ntawm ib leeg los ua cov ntawv luam tshiab, ua mRNA thiab ntxiv nucleotides los kho. Ob lub enzymes helicase thiab topoisomerase tuaj ua si ntawm lub sijhawm no. Yog li ntawd, ob qho tib si helicase thiab topoisomerases yog qhov tseem ceeb hauv DNA unwinding. Helicase cais ob-stranded DNA rau hauv ib leeg los ntawm kev rhuav cov hydrogen bonds ntawm nucleotide puag khub hauv ob-stranded DNA. Nyob rau hauv sib piv, topoisomerase unravels DNA twist thiab relieves DNA supercoil xwm los ntawm kev txiav cov DNA phosphate caj qaum nyob rau hauv ib los yog ob qho tib si strands.
Helicase yog dab tsi?
Helicase yog ib qho tseem ceeb enzyme thaum lub sij hawm DNA replication, transcription, recombination thiab kho. Helicase muaj peev xwm rhuav tshem hydrogen daim ntawv cog lus uas twb muaj lawm ntawm lub hauv paus ntawm ob qhov sib ntxiv ntawm DNA helix. Txhawm rau cais ob txoj hlua, helicase khi nrog DNA ntawm qhov chaw uas qhov kev sib txuas ntawm cov hlua tshiab pib. Nws tsim ib tug replication diav rawg thiab pib tawg ntawm hydrogen bonds ib tug los ntawm ib tug. Helicase siv lub zog ntawm ATP rau nws txoj haujlwm.
Daim duab 01: Helicase thaum DNA Replication
Ntxiv rau qhov saum toj no, muaj DNA helicases thiab RNA helicases. RNA helicases pab tag nrho cov txheej txheem ntawm RNA, suav nrog kev sau, sib txuas, thiab txhais lus, RNA thauj, RNA kho, thiab lwm yam.
Topoisomerase yog dab tsi?
Topoisomerase yog ib qho enzyme uas txiav DNA ntawm ib qho chaw tshwj xeeb thiab tshem tawm DNA twist thiab txo cov DNA supercoil xwm. Thaum lub sijhawm ua haujlwm helicase, supercoiling ntawm DNA tshwm sim vim yog cov qauv sib txuas ntawm ob-stranded DNA. Cov hom teeb meem saum toj no tsim nyob rau hauv DNA doubled strands tuaj yeem kho los ntawm topoisomerases. Lawv feem ntau txiav cov DNA phosphate caj qaum nyob rau hauv ib los yog ob qho tib si strands thiab tso cai rau DNA supercoil qauv kom tsis muaj mob. Tom qab ntawd, topoisomerase kaw DNA caj qaum dua.
Daim duab 02: Topoisomerase Action thiab Inhibition
Topoisomerase I thiab II yog ob hom topoisomerases uas cuam tshuam nrog supercoiled DNA. Topoisomerase Kuv txiav ib strand nyob rau hauv ob-stranded DNA tsis siv zog. Hauv qhov sib piv, topoisomerase II txiav ob qho tib si hauv DNA, siv ATP rau nws txoj haujlwm. Vim yog cov kev ua ntawm topoisomerase, DNA muaj peev xwm mus rau replication, transcription, kho thiab chromosomal segregation, thiab lwm yam.
Dab tsi yog qhov zoo sib xws ntawm Helicase thiab Topoisomerase?
- Helicase thiab topoisomerase yog ob lub enzymes xav tau rau DNA replication, transcription thiab kho.
- Ob lub enzymes pab hauv kev ua kom tsis muaj ob txoj hlua DNA.
Qhov txawv ntawm Helicase thiab Topoisomerase yog dab tsi?
Helicase enzyme lov cov hydrogen bonds ntawm lub hauv paus ntawm ob qho ntxiv ntawm DNA lossis RNA thiab cais ob txoj hlua ntawm ib leeg. Ntawm qhov tod tes, topoisomerase enzyme hloov cov supercoiling ntawm ob-stranded DNA los ntawm kev txiav phosphate qaum ntawm ob qho tib si hauv ib txoj hlua lossis ob txoj hlua. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm helicase thiab topoisomerase. Tsis tas li ntawd, helicase ua rau DNA thiab RNA, thaum topoisomerase tsuas yog ua rau DNA. Yog li, qhov no yog lwm qhov sib txawv ntawm helicase thiab topoisomerase.
Summary – Helicase vs Topoisomerase
Helicase yog ib qho enzyme uas cais ob txoj hauv kev ntawm DNA, RNA lossis DNA-RNA hybrid los ntawm kev rhuav tshem hydrogen bonds ntawm cov hauv paus. Nws ua nws txoj haujlwm los ntawm kev siv lub zog. Nyob rau hauv sib piv, topoisomerase yog ib qho enzyme uas tsim ib leeg-stranded los yog ob-stranded so los txo kev ntxhov siab thaum lub sij hawm supercoiling. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm helicase thiab topoisomerase. Ob lub enzymes tseem ceeb hauv DNA replication, transcription thiab kho.
