Ukuba kuhlelwe Apho rRNA. RRNA Ribosomal RNA: abalinganiswa kunye nenkcazelo ngesakhiwo

ezinto eziphilayo sele efunda isakhiwo kunye nomsebenzi emvelo enza iiseli ephilileyo, izityalo, izilwanyana kunye nabantu. Badumileyo phakathi kwabo unikwa iqela iikhompawundi ekuthiwa acid (enyukliya) asidi.

Kukho iindidi ezimbini: deoxyribonucleic acid (DNA) kunye ribonucleic. Owokugqibela iinguqulelo ezininzi: mRNA, tRNA kunye rRNA, ezahluke umsebenzi wabo kunye nendawo zalapha kwiseli. Eli nqaku unikezelwa ekufundeni mibuzo ilandelayo: apho kuhlelwe rRNA in prokaryotic kunye neeseli eukaryotic, yintoni na isakhiwo sayo kunye nentsingiselo.

ulwazi zembali

Sisihlandlo sokuqala yenzululwazi ribosomal acid inokufunyanwa kwizifundo yi R. Weinberg kunye S. Penman kwi-imi- 60 lwekhulu XX, wazichaza elifutshane polynucleotide molecule ezinxulumene RNA, kodwa eyahlukileyo lomhlaba isakhiwo kunye neentlenge ukungavumelani kwe ulwazi transfer RNA. Amaninzi, iimolekyuli zazo zifumaneka ukwakhiwa nucleolus, kunye organelles iseli - ribosomes linoxanduva Yindibanisela protein yeselula. Baye ngokuba ribosomal (Ribosomal RNA).

Abalinganiswa RNA

Ribonucleic acid, ezifana DNA, i Polymer apho monomers ezi nucleotides iintlobo-4: adenine, guanine, uracil kunye cytidine enxulumene neebhondi phosphodiester kwi iimolekyuli elide-ndixakene enye, aphothwe waziva kokuba ezintsonkothe ngokuthe kratya okanye Ukumila. Kukho kwakhona kabini-ndixakene Ribosomal RNA ibakho iintsholongwane RNA kwaye phinda imisebenzi DNA: ukugcina nangokusulela uphawu zamafa.

iintlobo ezintathu asidi ezifumaneka iseli kakhulu kangangokuba: matrix, okanye ulwazi, RNA zezithuthi Ribosomal RNA, ukuba ezo acid, kwakunye ribosomal acid, ibekwe kule nucleolus kwaye kukho icytoplasm yeseli eqhotyoshelweyo.

RNA Ribosomal nama-80% ye asidi ribonucleic esiseleni kunye nama-60% kwe ubunzima ribosome - organelle, cellular protein yokuqaphela. Zonke ezi ntlobo zingentla zithi kuhlelwe (amagama) kwiingingqi ezithile DNA, ezi zofuzo RNA. Ngexesha Yindibanisela molecule ababandakanyekayo enzyme - RNA polymerase. Indawo yeseli, apho rRNA ukuba kuhlelwe - na nucleolus, ophezu engundoqo karyoplasm.

Nucleolus, indima yalo Yindibanisela

Ezikwiiseli eziphilayo, ekuthiwa umjikelo iseli bahlule phakathi kwamacandelo ayo - interphase. Ngelo xesha, xa kwiseli isiqalo imizimba ashinyeneyo izakhiwo granular ekuthiwa nucleoli kwaye njengesakhi esibalulekileyo senkqubo yonikezelo zombini zemifuno kunye nezilwanyana iiseli zibonakala kakuhle.

Xa ezinto eziphilayo, kwafunyaniswa ukuba nucleoli ke organelles apho rRNA ukuba kuhlelwe. Olunye uphando kwakhokelela kwezona ukufunyanwa cytology lwe-DNA yeseli apho zofuzo banoxanduva isakhiwo kunye Yindibanisela asidi ribosomal zifunyenweyo. Baye ngokuba umhleli nucleolar.

Umququzeleli nucleolus

Ukuya kuma-imi- 60 kwinkulungwane XX eziphilayo yaba uluvo lokuba nomququzeleli nucleolus, ibekwe kwi yendawo constriction nezizisekondari ngo-13, 14, 15, 21 no-22 ezibini zofuzo, na uhlobo kwisiza esisodwa. Abaphandi inxaxheba ekufundeni umonakalo chromosome, ekuthiwa aberrations, baye bafumanisa ukuba ixesha umsantsa chromosome kwindawo le constriction secondary ukhandwa nucleoli kwi nganye iinxalenye zayo.

Ngoko ke, ezi zinto zilandelayo kufuneka kuchazwe: umququzeleli nucleolus ibandakanya akukho namnye kodwa eziliqela ngeso (genes) unoxanduva lokuqulunqa ye nucleolus. Kuwo kuhlelwe rRNA Ribosomal RNA yakheka enganeno protein-synthesizing cell organelles - ribosomes.

Yintoni ribosome?

Njengoko kuchaziwe ngaphambili, onke ezintathu iintlobo eziphambili RNA ezikhoyo esiseleni, apho baya kuhlanganiswa kwiindawo ezithile - zofuzo DNA. Oku kubangela ribosomal RNA ifomu ukhutshelo izakhiwo kunye iiproteni - RNPs leyo yenza inxalenye ebalulekileyo organelles elizayo, benjenjalo ukumemeza-subunits. Ngokusebenzisa pores kwi inwebu zenyukliya kungena kukho icytoplasm, zihamba kunye akha isakhiwo emanyeneyo kuso, ziqulathe imolekyuli kwaye-RNA kunye t-RNA, ebizwa polysomes.

Ribosome babe ezahlulwe sisithuba sisenzo ion calcium zikho ngohlobo subunits ezahlukeneyo. inqubo efanayo lwenzeka kwi lamagumbi ka kukho icytoplasm yeseli apho zenzeka iinkqubo translation - Wahlanganisa iimolekyuli iiproteni cellular. Le seli esebenzayo okukhulu Intili ukutya kwawo, kokukhona iqulethe ribosomes. Ngokomzekelo, iiseli lomongo wethambo, hepatocytes kunye isilwanyana ezingahlali yabantu iphawulwa linani elikhulu kwezi organelles ngaphakathi kukho icytoplasm.

ukuba beminwe njani izakhi rRNA?

Ngokusekelwe ngasentla, isakhiwo, iintlobo kunye nomsebenzi rRNA zofuzo zixhomekeke somhleli nucleolar. Bona amalungiselelo ngeso equlathe izakhi kweekhowudi RNA ribosomal. O. Miller, ukuqhuba uphando iiseli ovogenesis ntulo, indlela esekwe nokusebenza kwezi zofuzo. Ekubeni ukuba kuhlelwe iikopi rRNA (njalo-ebizwa transkriptanty primary) equlathe malunga 13h103 nucleotides nokuba inomlingani neentlenge ka 45 S. koko, le beesekethe ibanjwa inkqubo lokuvuthwa ophela uhlobo molekyuli ezintathu p-RNA neentlenge okuza ka 5.8 S, 28 S, kwaye 18 S.

Le indlela ukuyilwa p-RNA

Ukubuyela Miller imifuniselo eyayiphanda le Yindibanisela RNA ribosomal waza wabonisa ukuba DNA ukhonza indlela nucleolar (matrix) ukuze kwakhiwe p-RNA - transkriptanta. Kwakhona bafumanisa ukuba isixa-enzyme RNA iimolekyuli polymerase ixhomekeke kwinani asidi ribosomal ubuntwana (pre-rRNA), ezithi kwakheka. Emva koko ke nokuvuthwa (processing), kunye p-RNA iimolekyuli baqalisa ngoko nangoko ubopheleleke peptides, isiphumo siya kuba ribonucleoprotein - isakhiwo izinto ribosome.

Amanqaku asidi ribosomal kwiiseli eukaryotic

Ukuba imigaqo okuqhelekileyo isakhiwo lulonke iindlela zokusebenza ribosomes prokaryotic kunye eziphilayo yinyukliya babe tsitomolekulyarnye umahluko. Ukuze ufumane kubo, abaphandi isifundo wasebenzisa indlela ekuthiwa uhlalutyo X-ray. Kuye kwafunyaniswa ukuba ubukhulu bezinto ribosome eukaryotic kungoko ke p-RNA ifakiwe kulo, kunye neentlenge olukhulu ukungavumelani kwe 80 S. organelle, ukulahlekelwa ion nemagnesium, unako kwahlulwa ibe subunits ezimbini zalathisi 60 S 40 S. yamasuntswana Small uhlanganisa enye molecule ye acid kunye ezinkulu - ezintathu, ngamanye iiseli nucleated ziqulathe ribosomes, eziquka 4 polynucleotide helices acid alandelayo iimpawu: 28 s RNA - amawaka 5 nucleotides, 18 s - 2 amawaka 5 s - 120 nucleotides, 5, .. 8 S - 160. Le isahlulo apho rRNA ukuba kuhlelwe kwizisele eukaryotic - a disintegrations nucleolus nkohliso karyoplasm nucleus.

prokaryotes RNA Ribosomal

Ngokungafaniyo p-RNA phakathi kwiiseli nucleated, iintsholongwane asidi ribosomal ribonucleic ukuba amagama phezu isahlulo zixinaniswe ye DNA equlethe kukho icytoplasm wabiza nucleoid. Iqulathe zofuzo rRNA. Lungiselelo, uphawu jikelele apho angamelwa ulwazi inkqubo Yeremiya izakhi p-RNA ngokulandelelana DNA ye ribosomal ribonucleic acid nucleotide complementarity kunye imithetho ikhowudi yezofuzo: nukleoitid adenine iyangqinelana uracil, kunye guanine - cytosine.

iintsholongwane R-RNA ube nelitye esezantsi ezinto eziphilayo kunye nemilinganiso incinane iiseli nucleated. neentlenge yabo lomlingani S-70, yaye subunits ezimbini babe izalathisi 50 S kunye 30 S. The yamasuntswana ezincinane iqulethe enye molecule ye p-RNA, ezinkulu - ezimbini.

Indima ribonucleic acid ngexesha translation

Lo msebenzi ungundoqo rRNA kukubonelela ngenkqubo biosynthesis of weseli protini - Live. Kuyinto kuphela xa kukho ribosomes eziqulathe rRNA. Joyina ndawonye ngokwamaqela, bathe bandibopha ukuya DNA kolwazi uyila nkqubo. Ukuze ukusuka kwi icytoplasm iiseli zothutho molecule asidi ezifanelekileyo ribosomal ribonucleic ethwele acid, leyo, kanye polysomes kwadityaniswa ngeentambo peptide ukwenza Polymer - protein. Nguye lo iiseli ibalulekileyo ulungelelwaniso enze imisebenzi emininzi ebalulekileyo: ulwakhiwo, ezothutho, amandla, enzyme, ukhuseleko kunye umkhosi esandleni sakhe.

Eli nqaku bahlola isakhiwo iimpawu kunye nenkcazelo asidi ribosomal acid ezi zomgquba biopolymers iiseli izityalo, izilwanyana kunye nabantu.