Processing - shi ne ... RNA aiki (post-transcriptional RNA gyara)

Yana bambanta wannan mataki da aiwatar da data kasance kayyade bayanai a Kwayoyin kamar eukaryotes da prokaryotes.

Fassarar wannan ra'ayi

A Turanci, da kalmar na nufin "magani, sake amfani." Processing - shi ne samuwar balagagge RNA kwayoyin daga pre-RNA. A wasu kalmomin, wannan ya kafa halayen da kai zuwa ga canji na farko kwafi samfurin (pre-RNAs daban-daban) a cikin wani riga-aiki kwayoyin.

Dangane da aiki da p- da tRNA, shi sau da yawa zo saukar zuwa yankan kashe iyakar da kwayoyin da karin wani ɓaɓɓake. Idan muka magana game da mRNA, shi iya a lura a nan cewa, a eukaryotes, da tsari faruwa a dama, saukarwa.

Saboda haka, bayan mun koyi cewa aiki - shi ne canji na farko kwafi a cikin balagagge RNA kwayoyin, ya kamata a ci gaba da shawara na da fasali.

Babban fasali na ra'ayi

Wannan zai iya hada wadannan:

• gyara biyu na ƙyallen maƙalawa a kwayoyin da RNA, a cikin shakka daga abin da suke tare ne da takamaiman nucleotide jerin cewa nuna wuri farko (karshen) na watsa shirye-shirye.
• splicing - clipping uninformative ribonucleic acid jerin wanda dace introns DNA.

Amma prokaryotes, su ne ba batun da mRNA aiki. Yana yana da ikon yin aiki daga ƙarshen kira.

Ina fitowa cikin tsari a tambaya?

Duk wani kwayoyin RNA aiki faruwa a tsakiya. An za'ayi da takamaiman enzymes (su kungiyar) ga kowane mutum da irin kwayoyin. sarrafa ma iya fallasa zuwa wannan fassarar kayayyakin matsayin polypeptides wanda aka kai tsaye karanta daga mRNA. Wadannan canje-canje ne batun da ake kira precursor kwayoyin na mafi sunadaran - collagen, antibodies, narkewa kamar, (enzymes) da wasu hormones, sa'an nan yana farawa da ainihin aiki na jiki.

Mun riga mun fahimci cewa aiki - shi ne samuwar balagagge RNA daga pre-RNA. Yanzu shi wajibi ne don shiga cikin yanayin mafi ribonucleic acid.

RNA: da sinadaran halitta

Wannan shi ne wani ribonucleic acid, wanda shi ne mai copolymer na pyrimidine da purine ribonukleitidov wanda ake da alaka da juna, kamar yadda a cikin DNA 3 '- 5'-phosphodiester gadoji.

Duk da cewa wadannan nau'o'i guda biyu na kwayoyin ne irin wannan, suka sãɓã wa jũna a kan da dama filaye.

A halaye na RNA da DNA

Da fari dai, ribonucleic acid ne ba a cikin carbon saura ga wanda kafa uku pyrimidine da purine kwasfanta, da phosphate kungiyar - ribose, a DNA guda - 2'-deoxyribose.

Na biyu, da daban-daban aka gyara da kuma pyrimidine. Similar aka gyara ne nucleotides adenine, saitosin, Bibyun. A RNA, uracil ne ba maimakon taimain.

Na uku, RNA 1 yana da sarkar tsarin, da kuma DNA - 2-ƙuƙuntacce kwayoyin. Amma ribonucleic acid tufka ba rabo daga m polarity (karin jerin) da wanda shi ne iya guda sarkar da kuma gudan jini ta samar da "hairpin" - tsarin, baiwa da halaye na karkace-2 (kamar yadda aka nuna a sama).

Huxu, saboda RNA - guda sarkar, wanda shi ne karin zuwa na farko DNA tufka, Bibyun bukatar ba su kasance ba a cikinta, a cikin wannan abun ciki a matsayin saitosin, da adenine - uracil son.

Biyar, da RNA iya hydrolyzed da Alkali zuwa 2 ', 3'-diesters na cyclic mononucleotides. Rawar da matsakaiciyar hydrolysis taka 2 ', 3', 5-triester, iya samar a lokacin tsari kama da DNA saboda babu ta 2'-hydroxyl kungiyoyin. By kwatanta da DNA alkaline lability na ribonucleic acid ne mai amfani da dukiya ga bincike dalilai, da kuma for analysis.

The bayanai dauke a cikin 1-stranded RNA yana kullum aiwatar kamar yadda jerin purine da pyrimidine kwasfanta, wato, a primary polymer sarkar tsarin.

Wannan jerin ne karin sarkar gene (tsarinsa), tare da abin da RNA "readout." Saboda wannan dukiya daga ribonucleic acid kwayoyin iya musamman daura da coding sarkar, amma ba zai iya yin wannan tare da ba-coding DNA tufka. RNA jerin, fãce maye gurbin T U, kama da cewa ya ba da labarin wani da ba-coding sarkar gene.

iri RNA

Kusan dukkan su suna da hannu a cikin tsari kamar gina jiki biosynthesis. Known iri RNA:

1. Matrix (mRNA). Wannan cytoplasmic ribonucleic acid kwayoyin da cewa aiki kamar gina jiki kira matrices.
2. Ribosomal (rRNA). Wannan cytoplasmic RNA kwayoyin, bauta a matsayin tsarin da aka gyara kamar ribosomes (da wasu gabbansa da hannu a gina jiki kira).
3. Sufuri (tRNA). Wannan kai kwayoyin na ribonucleic acid din da suke da hannu a cikin translation (translation) mRNA bayanai cikin jerin amino acid a cikin sunadaran riga.

A gwaji ɓangare na RNA na farko tarihi cewa an samar a eukaryotic Kwayoyin, ciki har da dabbobi masu shayarwa Kwayoyin, fallasa a tsakiya ƙasƙanci tsari, da kuma taka da bayanai a cytoplasm ko tsarin rawa.

A adam Kwayoyin (ladabi) sami wani aji na kananan nukiliya ribonucleic acid ba kai tsaye da hannu a gina jiki kira, amma shafi RNA aiki, kazalika da total salula "gine." Da girmansu bambanta, su dauke da 90 - 300 nucleotides.

Ribonucleic acid - ainihin kayyade abu daga wani adadin ƙwayoyin cuta daga shuke-shuke da dabbobi. Wasu ƙwayoyin cuta dauke da RNA, ba wuce wannan mataki a matsayin baya kwafi na RNA a cikin DNA. Amma duk da haka saboda mutane da yawa dabba ƙwayoyin cuta, misali retroviruses, halin da baya da translation na genome RNA directed RNA-dogara baya kwafi (DNA polymerase) ta samar da 2-helical DNA kwafin. A mafi yawan lokuta bayyana 2-helical DNA kwafi da aka gabatar a cikin genome kara samar da magana daga kwayar halittar da kuma aiki lokacin da latest kwafin RNA kwayoyin (da kwayar).

Post-transcriptional gyare-gyare na RNA

Its kwayoyin ake hada da RNA polymerases, ko da yaushe aikin m precursors da aiki, wato pre-RNA. Suna canza kama zuwa wani riga balagagge kwayoyin kawai bayan wuce da dacewa post-transcriptional gyare-gyare na RNA - da matakai na ta maturation.

Da samuwar balagagge mRNA ya karanta a lokacin kira da RNA polymerase II a mataki elongation. By da 5'end na hankali girma tufka RNA a haɗe 5'end GTP, sa'an nan cleaved orthophosphate. Bugu da ari, tare da zuwan methylated Bibyun 7-methyl-GTP. Wannan ƙungiya musamman, wanda shi ne a wani ɓangare na mRNA, da ake kira "bugawa" (hat ko hula).

Dangane da nau'in RNA (ribosomal da kai, matrix, da dai sauransu) precursors an hõre daban-daban m gyare-gyare. Alal misali, precursors ake spliced mRNA, methylation, capping, polyadenylation, da kuma wani lokacin tace.

Eukaryotes: wani janar Siffar

eukaryotic cell abubuwa a matsayin yankin da masu rai, da kuma shi ya ƙunshi wani kwaya. Bugu da kari to kwayoyin cuta, archaea, duk kwayoyin ne nukiliya. Shuke-shuke, fungi, da dabbobi, ciki har da wani rukuni na kwayoyin, ya kira protists - duk da aiki eukaryotic kwayoyin. Su ne duka 1-cell da kwayar, amma duk da janar shirin na salon salula tsarin. An yi imani da cewa wadannan suna da bambancin kwayoyin da wannan asalin, a matsayin wani sakamako, wani rukuni na nukiliya riskarsa kamar wani monophyletic taxon daga cikin mafi girman daraja.

Bisa ga m jarrabawa, eukaryotes fito 1.5 - biliyan 2 da suka wuce .. Muhimmiyar rawa a juyin halitta su ne ba symbiogenesis - symbiosis eukaryotic Kwayoyin, wanda ya da zuciyar iya phagocytosis, kuma kwayan, ya yi lõma da ta - progenitor na plastids da mitochondria.

Prokaryotes: general halaye

Wannan 1-cell kwayoyin da ba tsakiya (rajista), da sauran membrane wasu gabbansa (ciki). The kawai manyan annular 2-sarkar DNA kwayoyin hada da manyan ɓangare na kayyade abu na cell ne daya wanda ba ya samar da wani hadadden tare da histone sunadaran.

Domin prokaryotes hada archaea da kwayoyin cuta, ciki har da cyanobacteria. Zuriyar enucleated Kwayoyin - eukaryotic wasu gabbansa - plastids, mitochondria. Sun kasu kashi 2 halittun cikin yankin daraja: Archaea da Kwayoyin cutar.

Wadannan Kwayoyin da ba su da makaman nukiliya ambulan, da DNA marufi faruwa ba tare da da hannu na histones. Osmotrofny su abinci irin da ya ƙunshi kwayoyin abu na daya jigidar halittar DNA wanda aka rufe a wani zobe, kuma akwai daya kawai replicon. A prokaryotes ne da wasu gabbansa da suke membrane tsarin.

Ba kamar eukaryotes daga prokaryotes

Da muhimman hakkokin alama na eukaryotic Kwayoyin ne alaka da binciken a su da kwayoyin inji, wanda aka located a cikin nucleus din, inda aka kiyaye shi ta wani harsashi. Su mikakke DNA hade tare da sunadarai histones, wasu sunadarai na chromosomes, wanda ba ya nan a kwayoyin. Yawanci, a cikin rayuwar sake zagayowar gabatar nukiliya 2 lokaci. Daya yana da wani haploid sa na chromosomes, kuma baya tattara abubuwa masu kyau, 2 haploid Kwayoyin samar da wata diploid, wanda riga qunshi na biyu kafa chromosomes. Yana kuma ya faru da cewa a gaba a cell raba sake zama haploid. Wannan irin rayuwa sake zagayowar, kazalika da diploidy a general, ba halayyar for prokaryotes.

The mafi ban sha'awa bambancin ne gaban takamaiman wasu gabbansa a eukaryotes, wanda suna da nasu kwayoyin na'ura kuma riɓaɓɓanya da division. Wadannan Tsarin suna kewaye da wani membrane. Wadannan wasu gabbansa ne mitochondria da plastids. Bisa ga tsarin rayuwa da kuma su ne abin mamaki kamar irin waɗanda na kwayoyin. Wannan shã'aninku sa masana kimiyya yi tunani game da gaskiyar cewa sun - zuriyar kwayan kwayoyin da cewa sun shiga symbiosis da eukaryotes.

A prokaryotes, akwai wani karamin yawan wasu gabbansa, babu wani daga wanda aka kewaye da wani biyu membrane. Sun rasa endoplasmic reticulum, da Golgi na'ura, da lysosomes.

Wani muhimmin bambanci 1 daga eukaryotes prokaryotes - gaban endocytosis sabon abu a eukaryotes, ciki har da phagocytosis a mafi kungiyoyin. A karshe ne da ikon kama ta shigar da wani kumfa membrane, sa'an nan nike da daban-daban m barbashi. Wannan tsari na samar da muhimmanci m aiki a cikin jiki. Da ya faru na phagocytosis, mai yiwuwa saboda gaskiyar cewa su Kwayoyin suna da wani talakawan size. Prokaryotic kwayoyin ne incomparably kasa, kamar yadda wani sakamako, a lokacin juyin na eukaryotes, akwai wata bukata hade da samar da Kwayoyin wani gagarumin adadin abinci. A sakamakon haka, na farko m da yara bayyana daga gare su.

Processing a matsayin daya daga cikin matakai na gina jiki biosynthesis

Wannan biyu lokaci, wadda ta fara bayan kwafi. Processing sunadaran ya auku ne kawai a eukaryotes. Wannan maturation na mRNA. Don zama daidai, shi ne kau da ƙasar da ba code for gina jiki, da kuma shiga iko.

ƙarshe

A cikin wannan labarin ta ne aka bayyana cewa wakiltar aiki (ilmin halitta). Har ila yau ya ce wannan RNA ya bada jerin sunayen da iri da kuma post-transcriptional gyara. Dauke da rarrabe fasali na eukaryotes da prokaryotes.

A karshe yana da daraja don tunatar da cewa aiki - shi ne samuwar balagagge RNA daga pre-RNA.