Basa reRNA mukugadzirwa kweprotini
Kugadzira mapuroteni inzira huru inoita kuti masero mapenyu akure, azvigadzirise, uye aite mabasa akasiyana-siyana ehupenyu. Seri kweiyi nzira, RNA (ribonucleic acid) inoita basa guru sechisungo pakati peruzivo rwemajini rwakachengetwa muDNA nekuumbwa kwemapuroteni mukati memasero. Pasina RNA, kodhi yemajini haigone kushandurwa kuita mamorekuru anoshanda akadai sema enzymes, mahormone, uye zvikamu zvemaumbirwo emasero. Chinyorwa chino chinokurukura basa reRNA mukugadzirwa kwemapuroteni, mhando dzeRNA dzinobatanidzwa, uye matanho akakosha ekuita.
RNA seMutakuri weRuzivo rweMajini
DNA inochengeta ruzivo rwemajini muchimiro chezvikamu zvenitrogen. Zvisinei, DNA inonyanya kuwanikwa munucleus yesero (mumasero eukaryotic) uye haishandiswi zvakananga kugadzira mapuroteni. Apa ndipo panopinda RNA: inoshanda sekopi inoshanda yeruzivo rwemajini. Kana ichienzaniswa neDNA, RNA ine misiyano yakati wandei yakakosha, yakadai sekushandisa ribose sugar, kutsiva uracil (U) ne thymine (T), uye kazhinji kuva netambo imwe chete. Hunhu uhwu hunoita kuti RNA ive nyore kushanduka pakubatana nezvikamu zvakasiyana-siyana zvemasero panguva yekugadzira mapuroteni.
Mhando dzeRNA Dzinobatanidzwa
Kune mhando nhatu huru dzeRNA dzinobatanidzwa zvakananga mukugadzirwa kwemapuroteni: mRNA, tRNA, uye rRNA. Dzese nhatu dzinoshanda pamwe chete kushandura ruzivo kubva kuDNA kuenda kuamino acid sequence chaiyo.
1. mRNA (mutumwa RNA)
mRNA iRNA inotumirwa neboka remagene. Basa rayo nderekutakura ruzivo rwemagene kubva kuDNA kuenda kuma ribosome, uko mapuroteni anounganidzwa. mRNA ine ma codon akatevedzana, ari mapoka ezvigadziko zvitatu zvenitrogenous, chimwe nechimwe chinomiririra amino acid kana stop signal. Nemamwe mashoko, mRNA ndiyo "script" iyo ribosomes inoverenga kuti iunganidze mapuroteni.
Mumasero eukaryotic, mRNA ichangobva kugadzirwa inogadziriswa isati yabuda munucleus. Maitiro aya anosanganisira kuwedzerwa chivharo che 5', kuwedzerwa kwemuswe we poly-A kumagumo e 3', uye kusunganidzwa kubvisa ma introns nekubatanidza ma exons. Kugadziriswa uku kunowedzera kugadzikana kwe mRNA uye kunoita kuti ikwanise kushandurwa nemazvo.
2. tRNA (kutamisa RNA)
tRNA inoshanda se "mutakuri" wemaamino acids kuenda ku ribosome. TRNA yega yega ine anticodon, mabhesi matatu anoenderana ne codon iri pa mRNA. Pamusoro pezvo, tRNA inotakura amino acid chaiyo kune rimwe divi rayo. Kana anticodon ikasangana ne codon inoenderana nayo pa ribosome, tRNA inoisa amino acid yainotakura mu polypeptide chain iri kukura.
Kururama kwetRNA mukutakura maamino acids kwakakosha. Maitiro aya anobatsirwa neenzyme inonzi aminoacyl-tRNA synthetase, iyo "inoisa" tRNA nemaamino acids akakodzera. Kana chikanganiso chikaitika, puroteni inobuda inogona kuva nechimiro uye basa rakasiyana.
3. rRNA (ribosomal RNA)
rRNA chinhu chakakosha che ribosomes, ma organelles uko kunoitika kugadzirwa kweprotein. Ribosomes dzinoumbwa ne rRNA nema ribosomal proteins. rRNA haingoshandi sechimiro che ribosomes chete asiwo ine simba re catalytic. Muzvinhu zvipenyu zvakawanda, rRNA inoshanda se ribozyme, RNA inogona kukurumidzisa makemikari. Mukugadzirwa kweprotein, rRNA inobatsira mukugadzirwa kwe peptide bonds pakati peamino acids, danho guru mukugadzirwa kweprotein.
Danho reKunyora: Kugadzira mRNA kubva kuDNA
Kugadzirwa kwemapuroteni kunotanga nekunyora, maitiro ekukopa ruzivo rweDNA mu mRNA. Kunyora kunoitika kana enzyme RNA polymerase yakabatana nepromoter muDNA, yobva yasunungura DNA helix younganidza cheni yeRNA zvichibva pakubatanidza base. Kana DNA iine base A, RNA ichawedzera U; kana DNA iine base T, RNA ichawedzera A; C pairs na G, uye zvinopesana.
Kunyora ma "transcription" kunogadzira pre-mRNA mu eukaryotes, iyo inozogadziriswa kuita ma "mature mRNA". Kana kugadziriswa kwapera, mRNA inobuda mu nucleus kuburikidza nema "nuclear pores" yopinda mu cytoplasm, uko kune ribosomes.
Danho rekushandura: Kushandura mRNA kuita mapuroteni
Kana mRNA yave mu cytoplasm, maitiro ekushandura anotanga. Kushandura kunoitika mu ribosome uye kune matanho matatu makuru: kutanga, kureba, uye kuguma. Munguva yekutanga, ribosome inoziva mRNA uye inotsvaga codon yekutanga (kazhinji AUG), iyo inoratidza kutanga kwekugadzirwa kweprotein. Codon yeAUG inorongawo methionine yeamino acid, saka methionine inowanzova amino acid yekutanga mu polypeptide chain.
Munguva yekureba, ribosome inofamba ichitevedza mRNA, ichiverenga ma codons rimwe nerimwe. TRNA yakakodzera inopinda mu ribosome, iine amino acid chaiyo. Ribosome inobva yaumba chisungo che peptide pakati pe amino acid itsva ne polypeptide chain iri kukura. Maitiro aya anodzokororwa, achirebesa polypeptide chain zvichienderana nekutevedzana kwema mRNA codons.
Danho rekupedzisira nderekuguma, uko kunoitika kana ribosome yasangana ne stop codon (UAA, UAG, kana UGA). Stop codon hainyore amino acid, asi inoratidza kuguma kwekushandurwa. Zvinhu zvinogumira zvinobatsira kuburitsa cheni yepolypeptide kubva mu ribosome. Polypeptide inobva yapetwa kuita chimiro chetatu-dimensional uye inogona kugadziriswa mushure mekushandurwa kuti ive protein inoshanda.
Basa reMamwe MaRNA Mukugadzirisa Kugadzirwa kweMapuroteni
Pamusoro pe mRNA, tRNA, uye rRNA, kune mamwe marudzi eRNA anoita basa rakakosha asi risina kunanga mukugadzirisa kugadzirwa kwemapuroteni, akadai se miRNA (microRNA) uye siRNA (small interferensing RNA). Aya maRNA madiki anogona kubatana ne mRNA uye kudzivirira kushandurwa kana kukonzera kuora kwayo. Saka, masero anogona kudzora kuti puroteni imwe inogadzirwa riini uye yakawanda sei. Mutemo uyu wakakosha pakukura kwezvisikwa, kupindura kushushikana, uye kudzivirira kugadzirwa kwemapuroteni zvisina kufanira.
Kukosha kweRNA kuHupenyu
Basa reRNA mukugadzirwa kwemapuroteni rinoita kuti molekyuru iyi ive chinhu chakakosha muhupenyu. RNA haisi kungori mutauriri asingashande, asiwo mutambi anoshanda, achivimbisa kushandurwa kwakarurama uye kwakanaka kweruzivo rwemajini. Kuburikidza nekushanda pamwe chete kwemRNA, inotakura mameseji, tRNA, inotakura maamino acids, uye rRNA, iyo inoumba nzvimbo inokonzeresa ribosomes, masero anokwanisa kugadzira mapuroteni anodiwa pamabasa ese ehupenyu.
Uyezve, kuwanikwa kwemaRNA anotonga akadai semiRNA kwakawedzera kunzwisisa kwedu kuti RNA ine basa rekudzora kutaura kwemajini, kwete kungokopa nekushandura ruzivo chete. Mu biotechnology nemushonga, kunzwisisa RNA kwakatungamira mukuvandudzwa kwemishonga yakavakirwa paRNA, kusanganisira majekiseni e mRNA uye matekiniki ekunyaradza majini achishandisa kupindira kweRNA.
Mhedziso
RNA inoita basa guru mukugadzirwa kwemapuroteni, kubva pakunyora ruzivo rweDNA kuburikidza nekunyora kusvika pakushandura kodhi yemajini kuburikidza nekushandura. mRNA inotakura meseji yemajini, tRNA inoita kuti maamino acids akakodzera atakurwe kuenda ku ribosome, uye rRNA inhengo yeribosome ine chimiro uye catalytic. Pamwe chete, RNA inobvumira kuumbwa kwakanyatsojeka kwemapuroteni zvichienderana nemirairo yemajini. Saka, RNA ndeimwe yemabhiriji makuru pakati peruzivo rwemajini nebasa rebhayoloji, zvichiita kuti ive nzvimbo inonyanya kukosha mubiology yemazuva ano yemamorekuru.
