Video: Dab tsi yog DNA polymerase kuaj xyuas kev hloov pauv?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Thaum DNA synthesis, thaum ib qho tsis raug nucleotide tau muab tso rau hauv tus ntxhais strand ntawm DNA , DNA polymerase rov qab los ntawm ib khub nucleotide, excises lub mismatched nucleotide thiab kho yuam kev. Yog li ntawd, lub DNA polymerase kuaj xyuas kev hloov pauv ntawm lub sijhawm DNA replication.
Ua kom pom qhov no, DNA polymerase tiv thaiv kev hloov pauv li cas?
Cov haujlwm proofreading ntawm DNA polymerase yog lub luag haujlwm rau kev tiv thaiv ntawm kev hloov pauv uas tshwm sim thaum rov ua dua . Ib zaug ib DNA polymerase kuaj pom qhov tsis raug nucleotide hauv paus hauv cov saw loj loj, nws nres rov ua dua thiab tshem tawm cov nucleotide tsis raug los ntawm kev ua haujlwm exonuclease thiab tiv thaiv kev hloov pauv.
Tom qab ntawd, lo lus nug yog, DNA polymerase ua li cas thiaj kuaj tau qhov yuam kev? DNA polymerase proofreading: proofreading los ntawm DNA polymerase kho yuam kev thaum rov ua dua . Kev Kho Tsis Zoo: Hauv kev kho tsis sib haum, qhov tsis raug-ntxiv lub hauv paus yog kuaj pom tom qab rov ua dua . Cov mismatch-kho cov proteins ntes lub hauv paus no thiab tshem tawm nws los ntawm qhov tshiab-synthesized strand los ntawm nuclease nkaus.
Hauv qhov no, DNA polymerase pov thawj li cas?
DNA polymerases yog cov enzymes tsim DNA hauv hlwb. Thaum DNA replication (copy), feem ntau DNA polymerases tuaj yeem ua tau "xyuas lawv cov haujlwm" nrog rau txhua lub hauv paus uas lawv ntxiv. Cov txheej txheem no yog hu ua kev nyeem ntawv . Polymerase siv 3' mus rau 5' exonuclease kev ua kom tshem tawm qhov tsis raug T los ntawm 3' kawg ntawm txoj hlua tshiab.
Dab tsi yog kev sib raug zoo ntawm DNA polymerases thiab kev hloov hauv DNA?
DNA polymerase tuaj yeem tiv thaiv a DNA mutation los ntawm qhov tshwm sim lossis nws tuaj yeem rov qab mus kho qhov teeb meem tsim. Gene qhia yog qhov tshwm sim ntawm noob rau hauv cov yam ntxwv tshwj xeeb.
Pom zoo:
Dab tsi yog qhov kev hloov pauv hloov pauv?
Kev hloov pauv, hauv molecular biology, yog hais txog kev hloov pauv hauv deoxyribonucleic acid (DNA), qhov twg ib qho (ob lub nplhaib) purine hloov pauv rau (ib lub nplhaib) pyrimidine, los yog vice versa
Dab tsi yog qhov txawv ntawm ib puag ncig kev hloov pauv thiab kev hloov pauv qub txeeg qub teg?
Qhov sib txawv ntawm cov yam ntxwv ntawm cov tib neeg ntawm tib hom yog hu ua variation. Qhov no yog inherited variation. Qee qhov kev hloov pauv yog qhov tshwm sim ntawm qhov sib txawv ntawm ib puag ncig, lossis ib tus neeg ua dab tsi. Qhov no yog hu ua environmental variation
Dab tsi yog kev saib xyuas ntawm kev ruaj ntseg sab hauv txawm tias muaj kev hloov pauv hauv ib puag ncig sab nraud?
Kev saib xyuas ntawm kev ruaj ntseg sab hauv txawm tias muaj kev hloov pauv hauv ib puag ncig sab nraud yog hu ua homeostasis
Dab tsi tsim cov roj siab thiab nws hloov pauv li cas nrog kev hloov pauv hauv kinetic zog?
Gas siab yog tshwm sim los ntawm kev sib tsoo ntawm cov khoom siv roj nrog rau sab hauv ntawm lub thawv thaum lawv sib tsoo nrog thiab tawm dag zog rau ntawm phab ntsa ntim. Tom qab ntawd cov roj yog cua sov. Raws li qhov kub ntawm cov roj nce, cov khoom tau nce lub zog kinetic thiab lawv cov nrawm nrawm
Peb qhov laj thawj tseem ceeb ntawm kev hloov pauv hloov pauv yog dab tsi?
Allele frequencies nyob rau hauv ib tug pej xeem yuav hloov vim plaub lub hauv paus zog ntawm evolution: Natural Selection, Genetic Drift, Mutations thiab Gene Flow. Kev hloov pauv yog qhov kawg ntawm cov alleles tshiab hauv cov noob caj noob ces. Ob ntawm cov txheej txheem tseem ceeb tshaj plaws ntawm kev hloov pauv hloov pauv yog: Natural Selection thiab Genetic Drift