Kukonzekera ndi ... RNA processing (zolemba za RNA zosinthidwa)

Ndi gawo ili lomwe limasiyanitsa kuzindikira kwa mauthenga omwe alipo alipo m'maselo monga eukaryota ndi prokaryotes.

Kutanthauzira lingaliro ili

M'Chingelezi mawu awa amatanthauza "processing, processing". Kukonzekera ndi njira yopanga ma molekyulu okhwima a ribonucleic acid kuchokera ku pre-RNA. Mwa kuyankhula kwina, izi ndizochitika zomwe zimayambitsa kusinthidwa kwa mankhwala oyambirira kusindikizidwa (Pre-RNA ya mitundu yosiyana) mu ma molekyulu ogwira ntchito kale.

Ponena za kugwiritsidwa ntchito kwa p-ndi tRNA, nthawi zambiri imatulutsa mamolekyu owonjezera kuchokera kumapeto a mamolekyu. Ngati tilankhula za mRNA, ndiye apa tingadziŵe kuti mu eukaryotes ndondomekoyi ndi multistep.

Choncho, titaphunzira kale kuti kusinthidwa ndi kusinthika kwa chilembo choyamba kukhala molekyulu ya RNA, tiyenera kuganizira zomwe zilipo.

Mfundo zazikulu za lingaliro

Izi zikuphatikizapo zotsatirazi:

• Kusintha kwa malekezero onse a molekyumu ndi RNA, pambali pake pamakhala zochitika zinazake za nucleotide, kusonyeza malo a chiyambi (mapeto) a kumasulira;
• Kuwaza - kudula zinthu zosaphunzitsanso za ribonucleic acid, zomwe zimagwirizana ndi makina a DNA.

Ponena za prokaryotes, mRNA yawo siikonzekera. Amatha kugwira ntchito mwamsanga pakatha kukambirana.

Kodi njirayi ikuchitika kuti?

Mulikonse, RNA processing ikuchitika mu mtima. Zimagwiritsidwa ntchito kudzera m'magulu (mwa gulu lawo) kwa mtundu uliwonse wa molekyu. Komanso, mapulogalamu omasuliridwa monga polypeptides omwe amawerengedwa mwachindunji kuchokera ku mRNA akhoza kusinthidwa. Zosinthazi ndizo zotchedwa mapuloteni ambiri a mapuloteni - collagen, immunoglobulins, mavitamini a m'mimba, mahomoni ena, kenako ntchito yawo imayamba m'thupi.

Taphunzira kale kuti kukonza ndi njira yokonzekera RNA yokhwima mu Pre-RNA. Tsopano ndibwino kukumba mu chikhalidwe cha ribonucleic acid.

RNA: chikhalidwe cha mankhwala

Ichi ndi ribonucleic acid, yomwe ndi copolymer ya pyrimidine ndi purine ribonucleotides, yomwe imagwirizana, monga DNA, milatho 3 '- 5'-phosphodiester.

Ngakhale kuti mitundu iwiriyi ya mamolekyu ndi ofanana, imasiyana mosiyanasiyana.

Zosiyana za RNA ndi DNA

Choyamba, pali carbon residu mu ribonucleic acid, yomwe pyrimidine ndi purine mabungwe, magulu a phosphate, ribose, ndi 2'-deoxyribose amamangirizidwa.

Chachiwiri, zigawo zikuluzikulu za pyrimidine zimasiyana. Zomwezo zimakhala ndi nucleotide za adenine, cytosine, guanine. Mu RNA, m'malo mwa thymine, uracil alipo.

Chachitatu, RNA ili ndi makina a 1, ndipo DNA ndi makilogalamu awiri. Koma mu mndandanda wa ribonucleic acid pali zigawo zomwe zimakhala zosiyana (zotsatira zoonjezera), chifukwa cha mndandanda umodzi womwe umatha kupukuta ndi kupanga "zipsinjo za tsitsi" - zomangamanga ndi makhalidwe a 2-helical (monga momwe taonera pa chithunzi pamwambapa).

Chachinayi, popeza RNA ndi mndandanda umodzi womwe umagwirizanitsa ndi imodzi yokha ya ma DNA, guanine sayenera kukhalapo mofanana ndi cytosine, ndipo adenine ali ngati chiwonongeko.

Chachisanu, RNA ikhoza kusungunuka ku 2 ', 3'-diester yamatsenga a mononucleotides ndi alkali. Udindo wa pakati pa hydrolysis umawonetsedwa ndi 2 ', 3', 5-triester, osakhoza kupanga njira yofanana ya DNA chifukwa ilibe magulu a 2'-hydroxyl. Poyerekeza ndi DNA, mphamvu zamchere za ribonucleic acid ndizofunikira zoganizira komanso zoganizira.

Zomwe zili mu RNA 1 zowonongeka zimadziwika ngati mapiri a pyrimidine ndi purine, mwazinthu zina, monga chiyambi chachikulu cha unyolo wa polima.

Zotsatirazi ndizokwanira kwa mndandanda wa ma gene (coding) omwe RNA "iwerengedwa". Chifukwa cha malowa, molecule ya ribonucleic acid imatha kumangirira mndandanda wa coding, koma sungathe kuchita izi ndi chingwe chosadziwika cha DNA. Zotsatira za RNA, kuphatikizapo kuika T ndi U, zikufanana ndi zomwe zimagwirizana ndi mndandanda wa ma genetiki.

Mitundu ya RNA

Pafupifupi onsewa amagwira ntchito monga protein biosynthesis. Mitundu yotsatira ya RNA imadziwika:

1. Matrix (mRNA). Izi ndi mamolekyu a cytoplasmic ribonucleic acid, omwe amakhala ngati mapuloteni omwe amatenga matrices.
2. Ribosomal (rRNA). Ndilo molekyumu ya RNA yoctoplasmic yomwe imakhala ndi gawo la ziwalo monga ribosomes (organelles omwe amagwira ntchito mu mapuloteni).
3. Zamagalimoto (tRNA) . Awa ndiwo ma molecule amtundu wa ribonucleic acid omwe amatenga nawo mbali yomasuliridwa (kutembenuzidwa) kwa mRNA chidziwitso mwa magawo a amino acid omwe ali kale mu mapuloteni.

Mbali yaikulu ya RNA monga mawonekedwe oyambirira omwe amapangidwa m'maselo a eukaryotic, kuphatikizapo maselo a mammalian, amatha kuwonongeka mu mtima, ndipo samasewera mbali yeniyeni kapena yolongosoka mu cytoplasm.

M'maselo aumunthu (okhwima), kalasi ya nuclear nuclear ribonucleic acid zomwe sizigwira nawo mwachindunji mapuloteni koma zimakhudza RNA processing, komanso magulu omwe amagwiritsidwa ntchito "zomangamanga", zapezeka. Masikelo awo amasiyana, ali ndi nucleotide 90-300.

Ribonucleic acid ndilo majini akuluakulu a mavairasi a zomera, zinyama. Mavairasi ena omwe ali ndi RNA samapita kudera loyamba monga RNA kukhala DNA. Komabe, kwa mavitamini ambiri, monga retroviruses, kutembenuzidwa mobwerezabwereza kwa RNA genome, yomwe imatsogoleredwa ndi RNA-dependent reverse transcriptase (DNA polymerase), imakhala ndi mapangidwe a 2-helical DNA copy. Nthaŵi zambiri, DNA yomwe imatulutsa mavitamini awiri, imayambitsidwa m'magazi, kumatsimikiziranso kuti majeremusi amawoneka komanso kuyambitsa makope atsopano a RNA genomes (komanso kachilombo).

Zosindikizidwa pamtundu wa ribonucleic acid

Mamolekyumu, omwe amapangidwa ndi RNA polymerases, nthawizonse amalephera kugwira ntchito, amachita monga zowonongeka, zomwe zisanachitike RNA. Zimasandulika kukhala ma molekyulu okhwima pokhapokha atatha kusintha kwa RNA pamasitepe - magawo a kusamba kwake.

Mapangidwe a mRNA okhwima amawerengedwa pa kaphatikizidwe ka RNA ndi polymerase II pachilumba cha elongation. Pafupifupi 5'-mapeto a kukula kwa pang'onopang'ono, RNA imayikidwa ndi 5'-mapeto a GTP, ndiye orthophosphate imachotsedwa. Komanso, guanine ndiyomwe imakhala ndi kufika kwa 7-methyl-GTP. Gulu lapaderali, lomwe liri gawo la mRNA, amatchedwa "kapu" (kapu kapena cap).

Malingana ndi mtundu wa RNA (ribosomal, transport, matrix, etc.), mawotcheru amatha kusinthidwa mosiyana. Mwachitsanzo, otsogolera mRNA amawombera, methylation, capping, polyadenylation, ndi nthawi zina kusintha.

Eukaryotes: khalidwe lodziwika bwino

Selo la eukaryotu limagwira ntchito monga chilengedwe cha zamoyo, ndipo liri ndi phokoso. Kuwonjezera pa mabakiteriya, nyamakazi, zamoyo zilizonse za nyukiliya. Zomera, bowa, nyama, kuphatikizapo gulu la zamoyo zomwe zimatchedwa ojambula, zimakhala ngati zamoyo za eukaryotic. Zonsezi ndi ma-1 komanso ma multicellular, koma onse ali ndi dongosolo lofanana la makompyuta. Zimakhulupirira kuti zamoyo zosiyana kwambirizi zimachokera kofanana, kotero kuti gulu la nyukiliya limawonedwa ngati tekoni ya monophyletic yapamwamba kwambiri.

Malinga ndi zifukwa zomwe anthu ambiri amaganiza, ma eukaryotes adayamba zaka 1.5-2 biliyoni zapitazo. Chinthu chofunikira pa kusintha kwawo chimaperekedwa ku symbiogenesis, symbiosis ya selo ya eukaryotic, yomwe inali ndi phokoso lotha kupangira phagocytosis, ndi mabakiteriya omwe amameza, mazembera a pulasitiki ndi mitochondria.

Prokaryotes: khalidwe lalikulu

Izi ndi zamoyo zamoyo 1 zomwe zilibe phokoso (zokongoletsedwa), maselo otsala a organoids (mkati). Molekyu wamkulu wa DNA wokhala ndi kachilombo ka 2 kamodzi kambirimbiri kamene kali ndi maselo a ma genetic ndi omwe sakhala ovuta ndi histone mapuloteni.

Ma prokaryotes akuphatikizapo amatsenga ndi mabakiteriya, kuphatikizapo cyanobacteria. Mbadwa za maselo opanda nyukiliya - organelles wa eukaryotes - plastids, mitochondria. Iwo amagawidwa mu ma teksi awiri mkati mwa udindo wawo: Archea ndi mabakiteriya.

Maselo ameneŵa alibe envelopu ya nyukiliya, kupaka DNA popanda kupezeka kwa histones. Mtundu wa zakudya zawo ndizochitika, ndipo ma genetic amaimiridwa ndi khungu la DNA, lomwe liri lotsekedwa mu mphete, ndipo pali 1 replicon yokha. Ma prokaryotes amakhalabe organoids, omwe ali ndi mawonekedwe a membrane.

Kusiyana pakati pa eukaryotes ndi prokaryotes

Mbali yaikulu ya maselo a eukaryotic ndi ofanana ndi kukhalapo kwa ma genetic, omwe ali pamtanda, kumene amatetezedwa ndi nembanemba. DNA yawo ndi yowonjezereka, yogwirizana ndi mapuloteni a histone, mapuloteni ena omwe alibe mabakiteriya. Monga lamulo, m'miyoyo yawo pali magawo awiri a nyukiliya. Mmodzi ali ndi ma hapromid ya ma chromosomes, ndipo kenako amagwirizanitsa, maselo awiri a haploid amapanga diploid, omwe ali kale ndi ma chromosome awiri. Zimakhalanso kuti pagawo lotsatila selolo limakhalanso haploid. Mtundu wamtundu uwu wa moyo, komanso diploidity mwachidziwikire, sali wofanana ndi ma prokaryotes.

Kusiyana kwakukulu kwambiri ndiko kukhalapo kwa organelle yapadera mu eukaryotes, omwe ali ndi zida zawo zowonongeka ndi kuchulukitsa ndi fission. Nyumbazi zikuzunguliridwa ndi nembanemba. Izi zimagwiritsa ntchito pulasitiki komanso mitochondria. Ponena za ntchito yofunika kwambiri, zimakhala zofanana kwambiri ndi mabakiteriya. Zinthu izi zachititsa asayansi kulingalira kuti iwo ali mbadwa za tizilombo toyambitsa matenda zomwe zakhala zikugwirizana ndi eukaryota.

Prokaryotes ali ndi organelles pang'ono, ndipo palibe yomwe imayandikana ndi memphane. Mwa iwo mulibe mapuloteni otchedwa endoplasmic reticulum, zipangizo za Golgi, ma lysosomes.

Chinthu china chofunika pakati pa eukaryotes ndi prokaryotes ndi kukhalapo kwa endocytosis mu eukaryotes, kuphatikizapo phagocytosis m'magulu ambiri. Wotsirizirayo amatchedwa kukwanitsa kulanda ndi ndende mu bululu wa membrane, ndiyeno amachepetsa zolimba zosiyanasiyana. Izi zimapereka ntchito yotetezera kwambiri m'thupi. Chiyambi cha phagocytosis, mwinamwake, ndi chifukwa chakuti maselo awo ali ofiira kukula. Zamoyo za Prokaryotic zimakhala zochepa kwambiri, motero, pakusintha kwa ma eukaryotsi, panafunikira chokhudzana ndi kupereka selo ndi chakudya chochuluka. Chotsatira chake, oyambirira oyendetsa mafoni amapezeka pakati pawo.

Kusintha monga gawo limodzi la mapuloteni biosynthesis

Ichi ndi gawo lachiwiri lomwe limayamba pambuyo polemba. Mapuloteni otsitsimula amapezeka kokha m'ma eukaryotes. Kusakaniza kwa mRNA. Kuti zitsimikizire, izi ndi kuchotsedwa kwa malo omwe samaphatikiza mapuloteni, komanso kugwirizana kwa olamulira.

Kutsiliza

Nkhaniyi ikufotokoza zomwe zikuchitika (biology). Komanso, kodi RNA imatanthauzidwa, zotani zomwe zimasinthidwa pambuyo pake? Zosiyana za ma eukaryot ndi ma prokaryotes amalingaliridwa.

Pomalizira pake, ndi bwino kukumbukira kuti kukonza njirayi ndi njira yopanga RNA yokhwima kuchokera ku Pre-RNA.