Inda aka hada rRNA. RRNA ribosomal RNA: faye hali da kuma bayanin irin tsarin

Ilmin sanin kwayoyin halittu da aka karatu da sifa da aiki da kwayoyin kwayoyin da cewa yin up rayayyun tantani na shuke-shuke, da dabbobi da mutane. Sananne daga gare su ne ba wani rukuni na mahadi kira nucleic (nukiliya) acid.

Akwai iri biyu: deoxyribonucleic acid (DNA) da kuma ribonucleic. A karshen yana da dama gyare-gyare: mRNA, tRNA da rRNA, abin da ya bambanta a cikin aiki da kuma wuri na sarrafawa a cikin cell. Wannan labarin da aka kishin nazarin wadannan tambayoyi: inda aka hada rRNA a prokaryotic da eukaryotic Kwayoyin, abin da yake da tsarin da kuma ma'anar.

tarihi bayanai

A farko kimiyya ambaci ribosomal acid za a iya samu a nazarin da R. Weinberg kuma S. Penman a cikin 60-ies na XX karni, wanda ya bayyana a takaice polynucleotide kwayoyin alaka RNA, amma daban-daban na sarari tsarin da sedimentation coefficient na bayanai da kuma canja wurin RNA. Mafi sau da yawa, su kwayoyin da ake samu a cikin abun da ke ciki na nucleolus, da kuma kwayoyin halitta - ribosomes, alhakin kira na salula gina jiki. Suka kira ribosomal (ribosomal RNA).

Faye hali na RNA

Ribonucleic acid, kamar DNA, shi ne mai polymer wadda monomers ne nucleotides 4 iri: adenine, Bibyun, uracil da cytidine alaka phosphodiester shaidu a cikin dogon guda-stranded kwayoyin, juya a cikin wani karkace da ciwon more hadaddun ko conformation. Akwai kuma biyu-stranded ribosomal RNA da ke faruwa a RNA ƙwayoyin cuta da kuma kwafi DNA ayyuka: rike da kuma watsa hereditary halaye.

Iri uku acid samu a cikin cell mafi sau da yawa shi ne: wani matrix, ko bayanai, RNA kai ribosomal RNA, to wanda aka a haɗe amino acid, kazalika da ribosomal acid, dake a cikin nucleolus da cytoplasm na cell.

Ribosomal RNA ne kamar 80% na ribonucleic acid a cikin cell da kuma 60% na taro da ribosome - organelle, salon salula gina jiki kira. All sama nau'in hada (a rubuce) a wasu yankuna na DNA, wadannan RNA kwayoyin halittu. A lokacin kira na kwayoyin hannu na musamman enzyme - RNA polymerase. Wuri a cikin wani cell, inda rRNA aka hada - ne nucleolus, wanda shi ne a kan karyoplasm core.

Nucleolus, da rawar a cikin kira na

A rayuwa Kwayoyin, kira cell sake zagayowar rarrabe tsakanin ta rarrabu - Interphase. A wannan lokaci, a cikin cell tsakiya m gawarwakin granular Tsarin kira nucleoli kuma shi ne wani muhimmin bangaren da biyu da kayan lambu da dabbobi Kwayoyin suna da kyau a bayyane.

A ilmin sanin kwayoyin halittu, an gano cewa nucleoli ne da wasu gabbansa inda rRNA aka hada. Kara bincike ya kai ga gano cytology sassa na cell DNA a wanda kwayoyin halittu suke da alhakin tsarin da kuma kira na ribosomal acid da aka samu. Suka kira nucleolar Oganeza.

nucleolus Oganeza

Up to 60-ies na XX karni a ilmin halitta da ya da wani ra'ayi cewa nucleolus Oganeza, located a kan site na da sakandare constriction a 13, 14, 15, 21 da 22 nau'i-nau'i daga chromosomes, yana da tsari guda site. Masu bincike da hannu a cikin binciken na chromosome lalacewa, kira aberrations, sun gano cewa, lokacin da rata chromosome a shafin na sakandare constriction da aka kafa nucleoli a kowane daga cikin sassa.

Saboda haka, da wadannan za a iya fada cewa: nucleolus Oganeza kunshi ba daya amma da dama loci (genes) alhakin samuwar nucleolus. Yana a cikinta hada rRNA ribosomal RNA kafa subunit furotin-rairaya kwayoyin halitta - ribosomes.

Mene ne wani ribosome?

Kamar yadda aka ambata a baya, duk uku main iri RNA zama a cikin cell, inda suke hada a wasu yankunan - DNA genes. A sakamakon ribosomal RNA kwafi form gidaje tare da sunadarai - RNPs na wanda Forms wani ɓangare na nan gaba da wasu gabbansa, da ake kira subunits. Ta hanyar pores a cikin nukiliya membrane cikin cytoplasm, su matsawa da kuma samar da wani united tsarin cikinta, hada da da kwayoyin da har yanzu-RNA da t-RNA, kira polysomes.

Ribosome kansu iya rabu da mataki na alli ions da kuma zama a cikin nau'i na raba subunits. Baya wannan tsari ya auku a cikin compartments na cell cytoplasm inda translation matakai faruwa - tattaro kwayoyin salula sunadaran. The aiki cell mafi maida sunã gudãna a cikinta metabolism, da more shi ya ƙunshi ribosomes. Alal misali, bargo Kwayoyin, hepatocytes da mutum vertebrate dabba halin da manyan yawan wadannan da wasu gabbansa cikin cytoplasm.

Yadda genes an shigar wanda ke aiki rRNA?

Bisa ta gabatar ba, cikin tsari, da iri da kuma aiki na rRNA genes dogara ne a kan nucleolar Oganeza. Suna shirya loci dauke da kwayoyin halittu coding for ribosomal RNA. O. Miller, gudanar da bincike a ovogenesis Kadangare Kwayoyin, da inji kafa aiki na wadannan genes. Tun da suka hada da kofe na rRNA (abin da ake kira primary transkriptanty) dauke da game 13h103 nucleotides da ciwon sedimentation coefficient na 45 S. Sa'an nan, wannan kewaye da aka gudanar ripening aiwatar kawo karshen nau'i uku kwayoyin na p-RNA sedimentation coefficients na 5.8 S, 28 S, da kuma 18 S.

Ginshikai na samuwar p-RNA

Komowa zuwa Miller gwaje-gwajen da diddigin kira na ribosomal RNA da DNA ya nuna cewa hidima nucleolar juna (matrix) domin samuwar p-RNA - transkriptanta. Ya kuma gano cewa adadin da enzyme RNA polymerase kwayoyin dogara da yawan m ribosomal acid (pre-rRNA), wanda aka kafa. Sa'an nan da maturation (aiki), da kuma p-RNA kwayoyin fara nan da nan daura da peptides, sakamakon wani ribonucleoprotein - gini abu ribosome.

Features ribosomal acid a eukaryotic Kwayoyin

Samun kowa akida, da kuma sauran tsarin da aikin sunadaran da prokaryotic ribosomes da makaman nukiliya kwayoyin har yanzu suna da tsitomolekulyarnye bambance-bambance. Don nemo su, binciken masu bincike ya yi amfani da hanyar kira X-ray analysis. An gano cewa da girma da eukaryotic ribosome kuma inganta p-RNA kunshe a shi, kuma mafi sedimentation coefficient na 80 S. organelle, rasa magnesium ions, za a iya raba cikin biyu subunits da Manuniya 60 S da kuma 40 S. Kananan barbashi hada da daya kwayoyin na acid da kuma manyan - uku, watau nucleated Kwayoyin dauke da ribosomes, kunsha na 4 polynucleotide spirals acid daga cikin wadannan halaye: 28 S RNA - 5 dubu. nucleotides, 18 S - 2 dubu. 5 S - 120 nucleotides, 5, 8 S - 160. a rabo inda rRNA aka hada a eukaryotic Kwayoyin - a nucleolus disintegrations arya a karyoplasm tsakiya.

Ribosomal RNA prokaryotes

Ba kamar p-RNA a cikin nucleated Kwayoyin, kwayan ribosomal ribonucleic acid suna a rubuce a kan matsa wa rabo daga cytoplasm dauke da DNA da ake kira nucleoid. Yana dauke da rRNA da kwayoyin halittu. Tsari, wani sifofinsu wanda za a iya wakilta bayanai rewriting aiwatar da p-RNA kwayoyin halittu a cikin DNA jerin ribosomal ribonucleic acid nucleotide complementarity da dokoki na kwayoyin code: adenine nukleoitid yayi dace uracil, kuma Bibyun - saitosin.

R-RNA kwayoyin da ƙananan kwayoyin nauyi da kuma karami girma fiye da nucleated Kwayoyin. Su sedimentation coefficient S 70, da kuma biyu subunits da Manuniya 50 S da kuma 30 S. The karami barbashi ƙunshi daya kwayoyin na p-RNAs, da kuma manyan - biyu.

Da muhimmancin da ribonucleic acid a lokacin translation

Babban aiki na rRNA ne don samar da wani tsari na biosynthesis na cell gina jiki - LIVE. Shi ne kawai a gaban ribosomes dauke da rRNA. Shiga tare a kungiyoyin, an ɗaure su cikin jigidar halittar DNA daga cikin bayanai kafa manufofin. Don shi daga cikin cytoplasm na sel dace kai kwayoyin ribosomal ribonucleic acid qazanta amino acid, wanda, da zarar a polysomes ciri da peptide bond ta samar da wata polymer - gina jiki. Shi ne mafi muhimmanci kwayoyin fili Kwayoyin yi yawa muhimmanci ayyuka: yi, kai, da makamashi, enzyme, lafiya da kuma yi sigina.

Wannan labarin yayi nazari da halayyar tsarin da kuma bayanin ribosomal nucleic acid ne kwayoyin biopolymers sel shuke-shuke, da dabbobi da mutane.