Processing - ke ... RNA sebetsa (poso-transcriptional RNA phetolo)

Ho distinguishes sethaleng sena ho kenngwa tshebetsong ha o teng lesedi liphatsa tsa lefutso liseleng tse kang eukaryotes le prokaryotes.

Tlhaloso ea khopolo ena

Ka Senyesemane, lentsoe le bolelang "kalafo, botjha ha thepa." Processing - ke sebopeho sa limolek'hule hōlileng tsebong RNA ho tloha pele ho RNA. Ka mantsoe a mang, sena sete a itšoare tse lebisang ho oa ho fetola mongwalollo sehlahisoa sa mathomo (ea pele ho RNAs ya mefuta e fapaneng) ka molek'hule se-sebetsa joang.

Mabapi le ho e lokisa ya p- le tRNA, hangata theoha ho khaola ea lipheletsong tsa limolek'hule tsa mangeta a ena e eketsehileng. Ha re bua ka mRNA, ho ka ho hlokomela mona hore ka eukaryotes, tshebetso nka sebaka ka mekhahlelo e 'maloa.

Ho joalo, ka mor'a hore re ithutile hore ho sebetsa - ke phetoho ea tlaleho mathomo ka ea hōlileng tsebong RNA molek'hule, ba lokela ho tsoela pele ho hlahloba makgetheng lona.

Likarolo tsa sehlooho tsa ya kgopolo ya ho

Sena se ka kenyeletsa tse latelang:

• tokafaditsweng lipheletsong bobeli tsa molek'hule le RNA, tseleng ea ba ileng ba ba ikopanya le tatellanong itseng nucleotide tse bontšang sebaka qala (qetellong) tsa hasoa ka;
• balance - clipping uninformative ribonucleic tatellanong asiti eo tsamaisana introns DNA.

Ha e le prokaryotes, ba ha ba ho ya sebetsa mRNA. Ho na le matla a ho sebetsa ho tloha qetellong ea tswakana ena.

Moo o tsoela pele mosebetsing oa ho e potso?

Leha e le ho e lokisa phelang RNA etsahala khubung ea. E etsoang ke enzyme e itseng (Sehlopha bona) bakeng sa motho ka mong limolek'hule mofuta. sebetswa hape ka kopana le lihlahisoa tse joalo phetolelo e polypeptides ho tse ka ho toba ho bala ho tloha mRNA. liphetoho tsena angoa ke ho seo ho thoeng ke selelekela limolek'hule liprotheine ho fetisisa - collagen, lisireletsi, tshilong ya dijo enzyme, ba bang ba li-hormone, 'me joale e qala tshebetsong sebele ea' mele.

Re se re ithutile hore sebetsa - ke sebopeho sa RNA ba hōlileng tsebong ho tloha pele ho RNA. Hona joale e se ke ho hlokahala hore delve ka mofuta wa ho fetisisa ea acid e ribonucleic.

RNA: mofuta lik'hemik'hale

Ena ke acid e ribonucleic, e leng copolymer tsa pyrimidine le purine ribonukleitidov tse amanang le mong ho e mong, feela joalokaha ka DNA 3 '- 5'-phosphodiester marokho.

Ho sa tsotellehe 'nete ea hore bana ba mefuta e' meli ea limolek'hule tse tšoanang, ba ile ba fapana ka mabaka a 'maloa.

Litšobotsi tsa RNA le DNA

Pele, acid e ribonucleic se teng ka har'a carbon masalla ho eo abut pyrimidine le purine makalana, ea phosphate sehlopha - ribose, ka DNA e tšoanang - 2'-deoxyribose.

Ea bobeli, metsoako e fapaneng le pyrimidine. dikarolo tšoanang ke nucleotides adenine, cytosine, guanine. Ka RNA, uracil se teng sebakeng sa thymine.

Boraro, RNA 1 e na le sebopeho ketane, le DNA - 2-tlameletsoe molek'hule. Empa ribonucleic acid e Strand joale likarolo tse ling tsa bo fapaneng polarity (tlatsanang tatelano) tseo ka tsona e le ea nang le bokhoni ea ketane ea se nang molekane 'me clot ho theha "hairpin" - sebopeho, re filoe litšobotsi tsa ho spiral-2 (joalokaha ho bontšitsoe ka holimo).

Ntlha ea bone, hobane RNA - ketane le 'ngoe, e leng e tlatsetsang ho pele DNA Strand, guanine ha ho hlokahale hore ho ba teng ho eona e le dikahare' ngoe le cytosine le adenine - uracil ratang.

Bohlano, ho RNA ka hydrolyzed le a alkali ho 2 ', 3'-diesters tsa mononucleotides cyclic. Karolo e phethoang ke hydrolysis lipakeng phetha 2 ', 3', 5-triester, ba sitoa ho theha nakong tshebetso tšoanang le DNA e loketseng ho ba sieo ha hae lihlopha 2'-hydroxyl. Ha ho bapisoa le DNA alkaline lability ea acid e ribonucleic ke thepa le thuso ya ho ka merero ea ho hlahloba lefu, 'me bakeng sa ho hlahlojoe.

Tlhahisoleseding ena ka 1-tsielehile RNA ka kakaretso sebediswa ho ka tatelano ea purine le pyrimidine makalana, ke hore, e le mathomo polymer ketane sebopeho.

tatelano Sena ke e tlatsetsang ketane phatsa ea lefutso (khouto), eo ka eona le RNA "readout." Ka lebaka la thepa ena ea ribonucleic acid e molek'hule ka ho toba tlama ho ketane tsoaneng e, empa ha le khone ho etsa sena le batho bao e seng Coding DNA Strand. RNA tatelano, ka ntle bakeng sa ho tlosa T U, e tšoanang le eo amana le batho bao e seng Coding ketane phatsa ea lefutso.

mefuta RNA

Hoo e ka bang kaofela ha bona ba ho ameha ka ho etsa joalo tse kang protheine biosynthesis. Tsebahalang mefuta RNA:

1. Matrix (mRNA). Sena cytoplasmic limolek'hule acid e ribonucleic hore ho sebetsa e le protheine tswakana matrices.
2. Ribosomal (rRNA). Sena cytoplasmic RNA molek'hule, ba sebeletsa e le dikarolo mehaho tse kang ribosomes (organelles amehang tswakana protheine).
3. Lipalangoang (tRNA). limolek'hule ena lipalangoang tsa acid ribonucleic tse amehang tlhahisoleseding phetolelo (phetolelo) mRNA be tatelano ea-amino acid ka liprotheine se.

Karolo e mohlomong tsa RNA tsa lingoliloeng pele hore ba se hlahisitseng ka lisele tse eukaryotic, ho akarelletsa le lisele tse mammalian, o ile a pepesa ho khubu thulaganyou e senyeha ha, 'me o phetha boitsebiso bo cytoplasm kapa karolo ea mehaho.

Liseleng tsa botho (rutehileng) o ile a fumana sehlopha sa ba tse nyenyane acid ea nyutlelie ribonucleic ha ba ameha ka ho toba ka tswakana protheine, empa amang RNA sebetsa, hammoho le palo yohle lisele "mehaho." boholo bo bona aa fapana, ba ba le 90 - 300 nucleotides.

Ribonucleic acid e - motheo liphatsa tsa lefutso tse bonahalang ho tswa ho tse ngata tsa likokoana-hloko ea limela le liphoofolo. Ba bang ba likokoana-hloko tse nang RNA, le ka mohla feta mohato tse kang mongwalollo khutlisetsang tsa RNA ka DNA. Leha ho le joalo bakeng sa likokoana-hloko tse ngata a liphoofolo, ka mohlala retroviruses, tšoauoa ka phetolelo khutlisetsang tsa liphatsa tsa lefutso RNA laela RNA-itšetlehileng ka khutlisetsang mongwalollo (DNA polymerase) ho theha 2-helical DNA kopi. Maemong a mangata ho hlaha 2-helical DNA tlaleho ile hlahiswa ka liphatsa tsa lefutso e ka ho eketsehileng ho fana ka pontšo ea liphatsa tsa lefutso ea vaerase 'me ka nako e ho sebelisa mehaho ea morao-rao genomes kopi RNA (le bongata ba kokwanahloko).

Post-transcriptional diphetolo tsa RNA

limolek'hule tsa lona di tsa maiketsetso le polymerases RNA, kamehla precursors ka tshebediso khathetseng moeeng hore a nke khato, e leng ea pele ho RNA. Ba re fetoleloa e molek'hule se hōlileng tsebong feela ka mor'a feta loketseng diphetolo poso-transcriptional tsa RNA - methati ea le nonofo ya mmele ea eona.

Sebopeho sa ba hōlileng tsebong mRNA se balileng nakong tswakana le RNA polymerase II ka mohato elongation. Ke 5'end ba butle-butle ho hōla Strand RNA khomaretse 5'end GTP, joale khomaretse orthophosphate. Ho feta moo, le qaleha ea methylated guanine 7-methylene-GTP. Sehlopha sena ho khetheha, e ka karolo ea mRNA, e bitsoang "capped" (katiba kapa cap,).

Ho itšetlehile ka RNA mefuta (ribosomal le lipalangoang, popeho, joalo-joalo) Precursors ba tlas'a diphetolo tse fapa-fapaneng e latellanang. Ka mohlala, precursors ba spliced mRNA, methylation, capping, polyadenylation, 'me ka linako tse ling tseleganya.

Eukaryotes: a kakaretso kakaretso

eukaryotic seleng e sebetsang sebakeng sa hae e le domain name ea lintho tse phelang, 'me ho na le ka hare ea nate. Ho phaella ho libaktheria, archaea, tse phelang tsohle ke tsa nyutlelie. Dimela, li-fungus, liphoofolo, ho akarelletsa le sehlopha se seng sa lintho tse phelang, e bitsoang protists - tsohle sebetsa phelang eukaryotic. Ba bobeli 1-sele le multicellular, empa kaofela ha leano kakaretso ya sebopeho sa lisele. Ho lumeloa hore tsena ke lintho tse joalo tse sa tšoaneng ba le tšimoloho e tšoanang, e le lebaka leo, sehlopha sa tsa nyutlelie lemohuoa ka taxon monophyletic la boemo bo tlaase ka ho fetisisa.

Thehiloe khopolo e tloaelehileng, eukaryotes hlaha 1.5 - limilione tse likete tse 2 lilemong tse fetileng .. karolo ea bohlokoa ho iphetola ha lintho tsa bona o fuoa symbiogenesis - symbiosis eukaryotic lisele tse, e neng ea mantlha ea nang le bokhoni ea phagocytosis, 'me baktheria, metsoa hae - moholo-holo oa plastids le mitochondria.

Prokaryotes: litšobotsi tse akaretsang

Sena se phelang 1-seleng eo na khubu (ngoliso), karolo e setseng ea organelles lera (ka hare). Feela kgolo annular 2-ketane DNA molek'hule se se akaretsang sa karolo e khōlō ea lintho tse bonahalang le liphatsa tsa lefutso tsa sele ke e 'ngoe eo ha e theha e rarahaneng le liprotheine histone.

Bakeng sa prokaryotes kenyeletsa archaea le libaktheria, ho akarelletsa le cyanobacteria. Litloholo enucleated lisele tse - eukaryotic organelles - plastids, mitochondria. Di arotswe 2 taxa ka hare boemo bo domain name le: Archaea le Libaktheria.

lisele tse tsena ha ba enfelopo nyutlelie, DNA ambalaji etsahala ntle le ho kenya letsoho histones. Osmotrofny mofuta bona lijo 'me e na le boitsebiso bo liphatseng tsa lefutso tsa' ngoe molek'hule DNA e koaloa ka lesale, 'me ho na le replicon le' ngoe feela. Ka prokaryotes ke organelles tse lera sebopeho.

Ho fapana le eukaryotes tloha prokaryotes

The tšobotsi ea bohlokoa ea lisele eukaryotic e amanang le mphumanang ka bona didirisiwa liphatsa tsa lefutso, e leng e teng khubung ea, moo e sirelelitsoe ke khetla e. DNA bona guttate amanang le liprotheine histones, liprotheine tse ling tsa chromosomes, tse sieo ka libaktheria. Ka tloaelo ho, ka bona potoloho bophelo hlahisa tsa nyutlelie 2 mohato. Motho ea nang le haploid sete ya chromosomes, 'me o ile kopanngwe, 2 lisele tse haploid theha diploid phase, eo se a ntse a kenyelletsa ditokiseletso le sete ea bobeli ea chromosomes. E boetse e etsahala hore ka lekhetlo le latelang seleng arola hape fetoha haploid. Ea mofuta ona e potoloho bophelo, hammoho le diploidization diploidy ka kakaretso, ha ba khetholloe ka ho prokaryotes.

Phapang e thahasellisang ka ho fetisisa ke ho ba teng ha organelles itseng ka eukaryotes, eo na le ipatlele liphatsa tsa lefutso sethusathuto bona atise ke karohano. dibopeho tsena pota-potiloe ke lera le. organelles tsena ke mitochondria le plastids. Ho ea ka sebōpeho sa bophelo 'me ba ho makatse hore ebe ka tsela e tšoanang le ea libaktheria. boemo Sena se ile sa bo-rasaense ba lokela ho nahana ka taba ea hore ba - litloholo tsa lintho tse phelang baktheria hore kene symbiosis le eukaryotes.

Ka prokaryotes, ho na le palo e fokolang ea organelles, ha ho eo e lika-likelitsoe ke lera la bobeli. Ba haelloa ke reticulum endoplasmic, ho Golgi sethusathuto, ho lysosomes.

phapang e 'ngoe bohlokoa 1 tloha eukaryotes prokaryotes - ho ba teng ha endocytosis ketsahalo ka eukaryotes, ho akarelletsa le phagocytosis ka lihlopha tse ngata. A ho qetela e le matla a ho hapa ke kena le take bubble lera, joale silehe e likaroloana tse fapa-fapaneng tiileng. Tshebetso ena e fana ka mosebetsi bohlokoa le sireletsang 'mele. The ketsahalo ea phagocytosis, mohlomong ka lebaka la 'nete ea hore le ka liseleng tsa bona ba le boholo karolelano. phelang Prokaryotic ke bapiswego tlase, ka lebaka leo, nakong ea ho iphetola ha lintho ea eukaryotes, ho na le e ne e le e hlokahalang amanang le phepelo ea lisele le palo e khōlō ea lijo. Ka lebaka leo, pele libatana e etsoang ka mechine bonahala har'a bona.

Processing le e mong oa mekhahlelo ea protheine biosynthesis

Sena mohato oa bobeli, eo e qala ka mora mongwalollo. Processing liprotheine le hlaha feela eukaryotes. Sena se popego ya mmele ea mRNA. Ho nepahetseng, ho ke ke ho tloswa ea naha eo se Code tsa protheine, 'me ho kopanela taolo.

bofello

A sehloohong sena a ho hlalosoa hore e emela sebetsa (baeloji). A boela a re RNA ena e thathamisa mefuta lona le phetolo poso-transcriptional. Tšohloa litšobotsi tse ikhethang tsa eukaryotes le prokaryotes.

Qetellong ho ke ke bohlokoa ho hopotsa hore sebetsa le - ke sebopeho sa RNA ba hōlileng tsebong ho tloha pele ho RNA.