Kukopana kweDNA
Kudzokorora DNA inzira huru yehupenyu inobvumira masero kutevedzera majini avo vasati vapatsanurana masero, kuitira kuti sero rega rega riwane kopi yakafanana yeDNA. Maitiro aya ndiwo hwaro hwenhaka yemajini uye anoita basa guru mukukura, kugadzirisa, uye kuchengetedza zvipenyu. Kunzwisisa mashandiro ekudzokororwa kweDNA hakungokoshi chete mubhayoloji yekutanga asiwo kune zvakunoreva zvakawanda muminda yakaita semajini, mishonga, uye biotechnology.
Maumbirwo eDNA uye Kukosha kweKudzokorora
DNA, kana kuti deoxyribonucleic acid, ndiyo molecule inochengeta ruzivo rwemajini mumasero. DNA ine tambo mbiri dzepolynucleotide dzinoumba double helix. Nucleotide yega yega ine boka rephosphate, deoxyribose shuga, uye imwe yenheyo ina dzenitrogenous: adenine (A), guanine (G), cytosine (C), uye thymine (T). Dzimba idzi dzinobatana zvakananga (A naT, uye G naC) kuburikidza nehydrogen bonds, zvichigadzira "rungs" yeDNA double helix.
Kudzokororwa kweDNA kunofanira kuitika nemazvo nekuti zvikanganiso zvinogona kukonzera shanduko dzinokuvadza. Uyezve, kudzokororwa kwakanaka kunoita kuti masero matsva akwanise kushanda zvakanaka, zvichichengetedza kuvimbika kwemajini echisikigo.
Matanho ekudzokororwa kweDNA
Kudzokororwa kweDNA kunoitika kuburikidza nematanho akatevedzana akarongeka, anosanganisira ma enzymes nemapuroteni akasiyana-siyana.
1. Kutanga
Maitiro ekudzokorora DNA anotanga panzvimbo chaiyo mumorekuru yeDNA inonzi "mavambo ekudzokorora" (ori). Mubhakitiriya, kazhinji pane ori imwe chete, nepo mueukaryotes, maori akawanda aripo kuti kukurumidzise maitiro ekudzokorora. Enzayimu yehelicase inotanga maitiro aya nekusunungura double helix, ichiparadzanisa tambo mbiri dzeDNA uye ichigadzira chimiro chinozivikanwa se "replication forogo."
Munguva iyi, mapuroteni ekubatanidza tambo imwe chete (SSB) anosimbisa tambo dzeDNA dzakaparadzana kuitira kuti dzisazobatanidzwazve. Tevere, primase enzyme inogadzira RNA primer pfupi inopa pokutangira DNA polymerase kuti itange kugadzira tambo itsva yeDNA.
2. Kureba
Kana primer yaiswa, enzyme yeDNA polymerase inotanga kugadzira tambo itsva yeDNA nekuwedzera manucleotide kune tambo iri kukura, zvichienderana nematanho chaiwo ekubatanidza. DNA polymerase inogona kurebesa tambo chete munzira ye5′ kusvika 3′. Saka, tambo imwe chete, inonzi tambo inotungamira, inoramba ichigadzirwa ichitevera nzira yeforogo yekukopa.
Kusiyana neizvi, tambo inopesana, inonzi tambo yakasara, inogadzirwa zvisingachinji sezvikamu zvipfupi zvinonzi zvikamu zveOkazaki. Chidimbu chimwe nechimwe cheOkazaki chinotanga neRNA primer uye chinozobatanidzwa pamwe chete kuti chigadzire tambo imwe chete inoenderera mberi.
3. Kugumiswa
Pakupera kwekukopa, RNA primer inobviswa yotsiviwa neDNA neDNA polymerase. Tevere, enzyme ligase inobatanidza zvidimbu zveOkazaki patambo iri kusara, zvichiita kuti tambo yeDNA irambe yakasimba uye isingachinji.
Muzvisikwa zve eukaryotic, nzvimbo dzakakosha dziri kumagumo ema chromosomes dzinonzi telomeres dzinodzokororwawo. Ma telomere anobatsira kudzivirira kurasikirwa neruzivo rwakakosha rwemajini panguva yekudzokororwa, uye enzyme telomerase inoita basa rakakosha mukuchengetedza kureba kwe telomere.
MaEnzymes nemaProtein Zvakakosha Mukudzokororwa kweDNA
Maenzyme akasiyana-siyana nemapuroteni anoita basa rakakosha mukubudirira kwekukopana kweDNA. Heano mamwe acho:
1. Helicase: Inovhura tambo mbiri yeDNA nekutyora zvisungo zvehydrogen pakati pemabhesi maviri, zvichiita forogo yekukopa.
2. Primase: Inogadzira maprimer mapfupi eRNA anopa pokutangira DNA polymerase.
3. DNA Polymerase: Inowedzera manucleotide kumagumo eprimer kana tambo iri kukura, zvichiita tambo itsva yeDNA.
4. DNA Ligase: Inobatanidza zvidimbu zveDNA zvakasiyana, kunyanya pakubatanidza zvidimbu zveOkazaki patambo iri kuseri.
5. Mapuroteni Anosunga Tambo Imwe Chete (SSB): Anosimbisa tambo dzeDNA dzakavhurika kuitira kuti dzisazobatanazve.
6. Topoisomerase: Inodzivirira kupinda kweDNA zvakanyanya nekutyora tambo imwe chete kana dzese dzeDNA kuti ibudise kushushikana, yozobatanidzazve.
7. Telomerase: Inorebesa matelomere kumagumo emachromosomes mu eukaryotes, zvakakosha pakugadzirisa dambudziko rekudzokororwa kwemachromosome.
Kururama uye Kugadzirisa Zvikanganiso
Kudzokorora DNA nemazvo kwakakosha pakuchengetedza kuvimbika kwemajini. DNA polymerase ine kugona kugadzirisa kunozivikanwa sekuongorora. Kana DNA polymerase ikaisa nucleotide isiriyo, inogona kuona kusawirirana uku, yocheka chikamu chisina kururama, yochitsiva nenucleotide chaiyo.
Pamusoro pezvo, kune nzira dzekugadzirisa mushure mekukopa dzinobata zvikanganiso zvisingaverengeki. Izvi zvinosanganisira kugadzirisa zvisina kuenderana, izvo zvinoona nekugadzirisa mabhesi akakanganisika.
Mashandisirwo uye Zvinorehwa neDNA Replication
Kunzwisisa kudzokororwa kweDNA kune mashandisirwo akawanda akakosha. Mu biotechnology, nzira yePolymerase Chain Reaction (PCR) inoshandisa misimboti yekudzokororwa kweDNA kuti iwedzere zvidimbu zveDNA zvakati wandei mu vitro. Nzira iyi inokosha mukutsvagisa majini, kuongorora mafambiro ezvirwere, kuongororwa kwezvirwere, nezvimwewo.
Mukurapa, kusashanda zvakanaka kweDNA replication kunogona kukonzera zvirwere zvakasiyana-siyana zvemajini nekenza. Kugadzira mishonga mitsva inotarisa ma enzymes chaiwo e replication mumasero ekenza inzvimbo yekutsvagisa kwakanyanya.
Mhedziso
Kudzokorora DNA inzira inokosha inoita kuti sero rega rega idzva riwane kopi chaiyo uye yakakwana yeDNA yaro. Kunyatsorongeka uye kushanda zvakanaka kwekudzokorora DNA kunochengetedzwa nekushandira pamwe kwema enzymes nemapuroteni akawanda. Nekunzwisisa kwakadzama kwekudzokorora DNA, tinogona kuramba tichiwedzera ruzivo rwedu rwema genetics, kuvandudza nzira dze biotechnology, uye kugadzira mishonga inoshanda zvakanyanya. Seimwe yenzira dzakakosha dzehupenyu, kudzokorora DNA kunoramba kuri chinhu chinonyanya kukosha pakutsvagurudza kwesainzi kuri kukura.
