Reparation: Ichi ndi chani? zimagwirira DNA kukonza

Reparation - khungu moyo chuma kuthana ndi ntchito zosiyanasiyana za kuwonongeka DNA. Mu dziko kunja pali zinthu zambiri zomwe zingachititse inasinthiratu ku zamoyo zina. Kuti tikhalebe okhulupirika, kupewa masinthidwe pathological ndi yosemphana ndi moyo, payenera kukhala dongosolo wodzilamulira kuchira. Monga linaphwanya umphumphu wa zinthu majini a selo? Taganizirani funso ili mwatsatanetsatane. Komanso fufuzani kodi thupi kukonza njira ndi momwe ntchito.

Kuvutika mu DNA ndi

Deoxyribonucleic asidi molekyulu akhoza kusweka m'kupita kwa biosynthesis komanso mchikakamizo cha zinthu zoipa. Zina mwa zinthu zoipa, makamaka, monga kutentha kapena mphamvu za chiyambi osiyana. Ngati wovulala zinachitika, selo reparation ndondomeko wayamba. Motero amayamba kubwezeretsa kwa kapangidwe choyambirira cha a DNA. Pakuti reparation kukumana maofesi yeniyeni enzyme kuti alipo mwa maselo. Popeza kulephera kwa maselo munthu kuchita zina matenda kuchira kugwirizana. The sayansi kuti amaphunzira njira kukonzedwa, - ndi zamoyo. Mkati chilango ikuchitika kwambiri ndi ziyeso ndi mayesero, chifukwa chimene kumakhala kosavuta kumvetsa ndondomeko kuchira. Tikumbukenso kuti njira ya DNA kukonza ndi chidwi kwambiri monga momwe mbiri ya anapeza ndi kuphunzira zodabwitsazi. Kodi ndi zinthu ziti amathandiza kuti chiyambi cha wolakwayo? Kuyamba mwamsanga, m'pofunika kuti DNA stimulator anakhudzidwa minofu kukonza. Kodi ilo, mochuluka kufotokoza pansipa.

History of anapeza

Izi chodabwitsa zodabwitsa anayamba kuphunzira American wasayansi Kellner. Woyamba anatulukira kwambiri pa ulendo wa kufufuza kukonza lafalikira monga photoreactivation. Izi Othandizira akuti otchedwa zoipa kuchepetsa zotsatira za UV walitsa ndipo pambuyo ankachitira anavulala selo yowala mtsinje wa kuunika kwa zooneka sipekitiramu kuwala kwa magetsi.

"Kuwala Kusangalala"

Kenako amaphunzira Kellner muli nkhani yopitiriza ntchito za akatswiri American Setlou, Rupert ndi ena. Chifukwa cha ntchito ya gulu la asayansi akhala molondola anakhazikitsa kuti photoreactivation ndi ndondomeko imene anayamba chinthu chapadera - puloteni kuti catalyzes ndi pogawanikana pamawere wa dimers thymine. Ndi iwo amene, monga kunapezeka, inakhazikitsidwa mu njira ya zatsopano pansi kuwala. Choncho kuwala kuonekera anapezerapo kanthu za enzyme, amene analimbikitsa pogawanikana pamawere wa dimers ndi kubwezeretsa chikhalidwe chapachiyambi cha minofu kuonongeka. Pankhaniyi tikulankhula zosiyanasiyana kuwala kwa DNA kukonza. Ife tanthauzo bwino. Tikhoza kunena kuti kuwala kukonza - ndi kubwezeretsa poyera kuti kuwala pambuyo dongosolo la kuwonongeka DNA pachiyambi. Komabe, ndondomeko izi sikuti zimathandiza kuti kuwonongedwa kwa choipa.

"Mdima" kuchira

Patapita nthawi yoyamba ya kuwala anali wapezeka mdima kukonza. chodabwitsa izi zimachitika popanda mphamvu iliyonse kunyezimira kuwala kwa sipekitiramu kuwoneka. sichisinthasinthanso anapezeka pa phunzirolo tilinazo mabakiteriya ena kuti ultraviolet kunyezimira ndi cheza ionizing. Mdima kukonza DNA - luso maselo kuchotsa kusintha kulikonse tizilombo deoxyribonucleic acid. Koma ayenera kuti izi si njira photochemical, mosiyana ayambe kuwala.

Limagwirira a "mdima" Kuwonongeka zotsuka

Kuzipenya mabakiteriya anasonyeza kuti patapita nthawi zina pambuyo zokhala ndi selo imodzi chamoyo analandira magawo a ultraviolet, chifukwa mu ena zigawo DNA zinawonongeka, selo nthawi njira zake mkati mwa njira inayake. Chifukwa, DNA kusinthidwa imangokhala chidutswa kudula ku unyolo wamba. Chifukwa kukonzanso mudzaze mipata ya kwa amino zidulo zinthu zofunika. M'mawu ena, inatenga resynthesis ya DNA. Oyamba asayansi chinthu choterocho monga mdima kukonza minofu - ichi ndi chinthu china mu akuyendayenda chodabwitsa luso kudziteteza nyama ndi munthu.

Kodi dongosolo yokonzanso

Zatsopano ndakufotokozerani ndi njira kuchira ndipo kuli kwambiri za luso limeneli, ankachiritsa ntchito zamoyo zokhala ndi selo imodzi. Koma njira kukonza ndi chibadidwe maselo a zinyama ndi anthu amoyo. Anthu ena amadwala xeroderma pigmentosum. matenda amayamba ndi kusowa mphamvu ya maselo resynthesize kuonongeka DNA. Xeroderma tinatengera. Zimene kukonza dongosolo? Anayi enzyme, amene amasunga kukonza ndondomeko - ndi DNA helicase, -ekzonukleaza, polymerase ndi -ligaza. Woyamba wa mankhwala awa akhoza kuzindikira kuwonongeka kwa maselo unyolo wa deoxyribonucleic acid. Iwo osati amaona komanso amadula unyolo mu malo oyenera, kuchotsa mbali ina ya molekyulu kusinthidwa. Gawo kuchotsa ikuchitika ndi DNA exonuclease. Kenako, kaphatikizidwe wa gawo latsopano deoxyribonucleic asidi molekyulu kwa amino zidulo ndi maganizo kwathunthu m'malo gawo zowonongeka. Chabwino mapeto lamavutoli njira kwachilengedwenso anachita ndi DNA ligase enzyme. Ndi udindo ubwenzi ku gawo kuonongeka kwa molekyulu apanga. Kamodzi michere onse anayi achita ntchito zawo, DNA kwathunthu kusinthidwa ndi mavuto onse a m'mbuyomu. Umu ndi momwe bwino ntchito njira m'kati mwa maselo amoyo.

Gawo

Pa nthawi imeneyi, akatswiri apeza mitundu zotsatirazi kachitidwe kukonza. Iwo adamulowetsa malingana zifukwa zosiyanasiyana. Njirazi ndi monga:

1. Reactivation.
2. Recombination kuchira.
3. Kukonza heteroduplexes.
4. Excision kukonza.
5. The reunification wa malekezero sanali magazi a mamolekyulu DNA.

zamoyo zonse zokhala ndi selo imodzi ndi machitidwe osachepera atatu enzymatic. Aliyense ali ndi mphamvu kugwiritsa ntchito ndondomeko kuchira. kachitidwe monga: mwachindunji, excision ndi postreplicative. The mitundu itatu ya DNA kukonza ndi prokaryotes. Koma eukaryotes, ndi akanagwiritsa ntchito, njira zina, ndipo amatchedwa Abiti-mathe ndi SOS-kukonza. Biology tikambirana mwatsatanetsatane zonse Mukuvetsa zimenezi wodzilamulira machiritso nkhani majini maselo.

Kapangidwe njira zina

Direct kukonza - ndi osachepera zovuta njira ndiyotani pakuchotsa kusintha pathological mu DNA lapansi. Iwo ikuchitika michere yeniyeni. Chifukwa cha iwo, kubwezeretsa kwa Kapangidwe ka DNA mofulumira kwambiri. Nthawi zambiri, njira atuluka mu sitepe imodzi. Mmodzi wa michere pamwamba ndi O6-methylguanine-DNA methyltransferase. Excision kukonza dongosolo - izi ndi mtundu wa kudziletsa machiritso a deoxyribonucleic acid, imene imakhudza kudula mu kusinthidwa kwa amino zidulo, ndipo anayamba m'malo malo awo kukonzanso apanga. Zimenezi ikuchitika mu magawo angapo. Pa postreplicative DNA anakonza dongosolo la molekyulu izi zikhoza kupangidwa mu unyolo kusiyana phindu. Ndiye anatseka ndi nawo RecA mapuloteni. Postreplicative kukonza dongosolo ndi wapadera kuti ndondomeko yake sadziwa gawo kudziwika kusintha tizilombo.

Amene ndi udindo limagwirira ayambe

Pakali pano, asayansi kudziwa kuti cholengedwa chosavuta E. coli, ali zosachepera makumi asanu majini mwachindunji kwa kukonza. Jini iliyonse ali ndi udindo winawake. Zikuphatikizapo: kudziwika, kuchotsa, kaphatikizidwe, ubwenzi, chizindikiritso cha zotsatira za UV cheza, ndi zina zotero. Mwatsoka, majini aliyense, kuphatikizapo amene ali ndi udindo njira yokonza muchipindachi, pansi kusintha mutational. Ngati zimenezi zachitika, ndiye iwo kukhazikitsa masinthidwe pafupipafupi maselo zonse za thupi.

Zolusa kuwonongeka DNA

Tsiku lirilonse, DNA a maselo a thupi lathu ali pachiopsezo cha kuwonongeka ndi kusintha pathological. Izi ntchito ndi zinthu zachilengedwe monga cheza ultraviolet, zina chakudya, mankhwala, kutentha monyanyira, maginito mavuto ambiri amene kuyambitsa njira yeniyeni mu thupi, ndi zambiri. Ngati kapangidwe DNA wasweka, zingayambitse maselo aakulu kusintha ndipo kungachititse kuti khansa m'tsogolo. Ndicho chifukwa chake thupi ndi zovuta kwa njira kuthana ndi kuvulala amenewa. Ngakhale michere amalephera kubwerera kwa maonekedwe yoyambirira ya DNA, kukonza dongosolo chichita kusunga kuwonongeka yochepa.

magazi recombination

Ife amvetse izo ziri. Recombination ndi kuuzana nkhani maselo a kusiyana ndi pawiri mamolekyulu asidi deoxyribonucleic. Ngati kumene kuli chiphwanya mu DNA ndi magazi recombination ndondomeko akuyamba. Pa izo umasinthanitsidwa makombo a mamolekyulu awiri. Ndi molondola anabwezeretsa dongosolo choyambirira cha deoxyribonucleic acid. malowedwe a DNA angayambe zina. Kudzera njira ya recombination n'zotheka cigawo zinthu ziwiri zosiyana.

Limagwirira kuchira thupi ndi thanzi

Yokonzanso - ndi choyambilira mwa kugwira ntchito yachibadwa ya thupi. Pokhala pansi tsiku ndi ola lililonse kumuopseza DNA kuwonongeka ndi masinthidwe, kapangidwe multicellular Amasintha ndi moyo. Izi zimachitika komanso chifukwa dongosolo anakhazikitsa kukonza. Chosowa sichisinthasinthanso yachibadwa chimayambitsa matenda kusintha ndi kuvutika ena. Izi zosiyanasiyana kudwala, Oncology ndipo ngakhale okalamba yokha. matenda otengera chifukwa chisokonezo kukonzedwa kungachititse kuti chaukali zotupa zilonda ndi kuvutika ena a chamoyo. Tsopano kuzindikiridwa matenda ena oyambitsidwa ndi malfunctioning ndi machitidwe kukonza DNA. Awa Mwachitsanzo, matenda ngati Cockayne syndrome, xeroderma, nonpolyposis khansa ya m'matumbo, Trichothiodystrophy ndi ena khansa.