Chii reduplication DNA? Pfungwa DNA kuberekana

Morekuru reDNA - riri mu chromosome mamiriro. Mumwe chromosome rine chimwe Morekuru rine tambo mbiri. Reduplication DNA - ndiko kutapurirana mashoko pashure vaizviita kubereka vana shinda kubva mumwe Morekuru kune mumwe. It tinoberekwa zvose DNA uye RNA. Nyaya ino inokurukura kuti DNA kuberekana rikurumidze.

General mashoko uye mhando DNA usage

Zvinozivikanwa kuti yakakoswa neshinda iri Morekuru. Zvisinei, apo chirongwa DNA kuberekana kunotanga, ivo dispiralized, ipapo anoenda padivi, uye bhuku idzva mumwe nomumwe synthesized. Pamusoro kupera pane vaviri zvachose kufanana mamorekuru, chimwe nechimwe pane mubereki uye mwana shinda. kwetunhu ichi anonzi Semi-kuchinja. DNA mamorekuru tichida, apo akasara rimwe centromere, uye pakupedzisira diverge chete kana ichi centromere nokupesana kwacho kunotanga.

Mumwe mhando unonzi reparative kwetunhu. Iye, kusiyana yaimbovapo, hauna chokuita chero sero pachikuva, asi inotanga iri huye DNA kukuvara. Kana vari zvakare paupamhi-siyana hunhu, sero pakupedzisira anofa. Zvisinei, kana zvaparadzwa iri vemo, zvino unogona ovadzorera. Zvichienderana dambudziko uchadzoreredzwa kana kuparadzanisa tambo mbiri DNA panguva kamwe. Izvi, sezvazvakanyorwa kunzi: unscheduled kwetunhu hakurevi kutora nguva yakareba uye haatarisiri yakawanda simba.
Asi kana paine reduplication DNA, ipapo aipedza yakawanda simba, zvinhu, akatambanudza kureba wachi yake.
Reduplication inokamukana zvikamu zvitatu:

• kudzidziswa;
• elongation;
• kugumiswa.

Ngatikurukurei kutevedzana kwezviitiko DNA kuberekana.

kudzidziswa

In DNA dzevanhu - zvishoma makumi emamiriyoni hwaro vaviri vaviri (mhuka ivo kuverenga chete zana namakumi mapfumbamwe). DNA reduplication kunotanga munzvimbo dzakawanda nengetani zvinotevera zvikonzero. Around iyoyo iri RNA transcription kunoitika, asi ari kwetunhu DNA iri chakarembera vamwe vakasarudzwa nzvimbo. Naizvozvo, yakadai mutoo pamberi zvakakwana chitsama pafuma rinoungana iri cytoplasm masero rokutsigira Gene mashoko uye cellular basa asina kuputswa. Tichifunga izvi, muitiro zvinofanira kuitika nokukurumidza sezvinobvira. Kutepfenyurwa panguva iyi kuitwa, uye transcription haina kuitwa. Ongororo dzakaratidza kuti DNA reduplication kunoitika kamwe zviuru pakawanda mu - zviduku munzvimbo ine yakananga nucleotide kutevedzana. Vari vakabatana chaiyo initiator mapuroteni, izvo zvinozoita anobatanidzwa nevamwe makemikari ose DNA kuberekana.

The DNA Chidimbu riri synthesized anonzi replicon. Rinotanga kubvira pakutanga uye inoguma kana enzayemu terminates kuberekana. Replicon ndiye zvionera, uye anopa yose muitiro oga-software kwayo.
Hazvidzikisi kutanga pfungwa zvose kamwechete, kumwe kuchitanga kwokutanga, kumwe - akazotevera; Zvinogona kutora nzvimbo imwe kana mbiri pakatarisana mirayiridzo. Zviitiko kuitika zvinotevera kuti kana mufananidzo:

• kuberekana nemaforogo;
• RNA lähikuva.

kuberekana forogo

Chikamu ichi kupa kwacho usingafadzi ari vasingadiwi pemavara vari synthesized DNA deoxyribonucleic filaments. Plugs Saka kuumba vanonzi ziso kuberekana. The muitiro wacho pashure anoverengeka nezviito:

• ngurwa chokuita histones ari nucleosome - makemikari akadai DNA kuberekana methylation, acetylation, uye phosphorylation kubudisa nemakemikari kuti pave mapuroteni vanorasikirwa mutariri wavo akanaka kuti hwezvekukurukurirana kusunungurwa kwavo;
• despiralization - iri unwinding, riri zvakafanira kuti humwe kusunungurwa shinda;
• kuputsa rehydrogen zvisungo pakati DNA tambo;
• siyana avo akasiyana mativi Morekuru;
• Kuda kutamba yokuvamba uchishandisa SSB mapurotini.

RNA lähikuva

Reongororo anotakura ane enzayemu inonzi DNA polymerase. Zvisinei, kutanga kwake asingagoni, saka itai zvimwe makemikari - the RNA polymerase, rinonziwo RNA primers. Ivo synthesized mu zvakafanana tambo kuti deoxyribonucleic pamusoro nheyo complementarity. Saka, mharuro RNA kwetunhu miviri, vaviri primers uye kutsauka zvakundikana DNA tambo.

elongation

Nguva iyi inotanga kubva nucleotide Kuwedzera uye 3 'kuguma RNA-lähikuva, izvo anotakura kare kutaurwa DNA polymerase. It kwakunoitwa kune wokutanga wechipiri, nucleotide wechitatu, uye zvichingodaro. New shinda hwaro chokuita kuti cheni mubereki maererano rehydrogen zvisungo. Zvinonzi vaidavira kuti kwetunhu rwebhuruu iri 5 '- 3'.
Parinowanika kumbowanikwa parutivi kuberekana forogo, kubatana kwetunhu kunoitika nguva dzose uye panguva imwe chete Lengthens. Naizvozvo, shinda iyi anonzi kutungamirira kana kutungamirira. Iye RNA lähikuva hakuchisina kuumbwa.

Zvisinei, pakatarisana beach nomubereki DNA nucleotides kuramba abatane RNA lähikuva, uye deoxyribonucleic cheni iri synthesized mu negwara kubva kuberekana forogo. Muchiitiko chino, inonzi yanonoka kana lagging.

On the lagging beach usage kunoitika muna zvimedu, sezvamakaropafadzwa mumwe mugumo chikamu kwetunhu rinotanga imwe nzvimbo pedyo kushandisa iroro RNA lähikuva. Saka, pane vaviri kunonoka cheni chomudziyo vari akabatana DNA uye RNA. Dzinonzi Okazaki zvimedu.

Zvadaro zvose inodzokororwa. Zvadaro spliced mumwe kwezana akamonyoroka, rehydrogen kuparuka kukurukurirana shinda kumativi, achitungamirira cheni mazhinji panguva lagging synthesized anotevera kukamuka RNA lähikuva, pakwakanga - Okazaki kukamuka. Zvadaro, munyika kunonoka-beach RNA primers anoparadzwa uye DNA zvimedu vari akabatana imwe. Saka dunhu iri kunoitika panguva imwe chete:

• nokuumbwa itsva RNA lähikuva;
• kwetunhu Okazaki zvimedu;
• kuparadzwa RNA primers;
• zvakare kupinda redunhu rimwe chete.

kumisa

The kwacho kunoramba sokuvapo vaviri regai kundosangana kuberekana forogo, kana mumwe wavo dzichapera pamugumo Morekuru. Pashure pomusangano, nezvikokovonho zvenyama DNA mwanasikana tambo vari vakabatana ne enzayemu. Kana, kana chivhariso inodedera kurutivi kuguma Morekuru, DNA reduplication unoguma kushandisa chaiwo makemikari.

gadziriso

In iyi, basa rinokosha iri basa kudzora (kana kururamiswa) kuti kuberekana. Kuisa kwetunhu anogamuchira zvose mhando ina nucleotides, uye vachiongorora parutivi DNA polymerase pairing anosarudza avo kuti inodiwa.

The aida nucleotide kuti kukwanisa kuumba rehydrogen zvisungo uyewo nucleotide akafanana pamusoro template DNA beach. Uyezve, pakati shuga-phosphate muzongoza vanofanira imwe kugara kure zvakafanana zvindori matatu zvigadziko zviviri. Kana nucleotide asingadi zvinodiwa izvi, kubatana hazvizoitiki.
Control rinoitwa isati wakazopinzwa redunhu uye vasati kutendeukira pamusoro haizopereri nucleotide. Pashure paizvozvo, kubatana kusvika nomuzongoza saharofosfata.

mutational variability

The mashandiro DNA kuberekana, pasinei mukuru chikamu zvakarurama nguva dzose kuvhiringidzika filaments, makatumidzwa kunyanya "Gene kunotouraya." About pakadarowo mbiri chiuru, pane chimwe chikanganiso kuti konvariantnaya inonzi reduplication.

Zvinoitika nezvikonzero zvakasiyana. Somuenzaniso, pane mukuru kana akanyanya yakaderera kuwanda nucleotides deamination pamusoro cytosine, kuvapo mutagens vari kwetunhu zvose. Mune zvimwe zviitiko, kukanganisa inogona kururamiswa kugadzira pezvakaitwa mune dzimwe kururamiswa zvisisakwanisiki.

Kana kukuvara zvakakanganisa hope nzvimbo, kukanganisa havazofaniri migumisiro kana pane DNA kuberekana rikurumidze. Nucleotide kutevedzana kwezviitiko zviratidzo anogona kuitika pamwe kuberekesana kukanganisa. Zvino haisi nyaya, uye kunaka mugumisiro kungafanana rufu muchitokisi, uye rufu yose muviri. Zvinofanira kurangarirwa kuti Gene kunotouraya dzinobva mutational variability, izvo zvinoita majini mudziva plasticity.

methylation

Panguva kwetunhu, kana pakarepo pashure zvikaitika methylation ngetani. Zvinofungidzirwa kuti izvi zvinokosha kuti munhu kuumbika okutodza uye chengetedza Gene transcription. In izvi mabhakitiriya DNA anoshanda ayo kudzivirira achicheka makemikari.