Karolo ea RNA ho Synthesis ea Protheine
Ho kopanya protheine ke mokhoa oa motheo o nolofalletsang lisele tse phelang ho hola, ho itokisa, le ho etsa mesebetsi e fapaneng ea baeloji. Ka mor'a mokhoa ona, RNA (ribonucleic acid) e bapala karolo ea bohlokoa e le khokahano pakeng tsa tlhahisoleseling ea liphatsa tsa lefutso e bolokiloeng ho DNA le ho thehoa ha liprotheine ka har'a lisele. Ntle le RNA, khoutu ea liphatsa tsa lefutso e ke ke ea fetoleloa ho limolek'hule tse sebetsang tse kang li-enzyme, lihormone le likarolo tsa sebopeho sa lisele. Sengoloa sena se tšohla karolo ea RNA ho kopaneng ha protheine, mefuta ea RNA e amehang, le mekhahlelo ea bohlokoa ea ts'ebetso.
RNA e le Mojari oa Tlhahisoleseding ea Liphatsa tsa Lefutso
DNA e boloka tlhahisoleseding ea liphatsa tsa lefutso ka mokhoa oa tatellano ea metheo ea naetrojene. Leha ho le joalo, DNA e fumaneha haholo-holo ka har'a nucleus ea sele (liseleng tsa eukaryotic) 'me ha e sebelisoe ka ho toba ho etsa liprotheine. Mona ke moo RNA e kenang teng: e sebetsa e le kopi e sebetsang ea tlhahisoleseling ea liphatsa tsa lefutso. Ha e bapisoa le DNA, RNA e na le liphapang tse 'maloa tsa bohlokoa, joalo ka ho sebelisa tsoekere ea ribose, ho nkela uracil (U) sebaka ka thymine (T),' me ka kakaretso e le strand e le 'ngoe. Litšobotsi tsena li etsa hore RNA e tenyetsehe haholoanyane ha e sebelisana le likarolo tse fapaneng tsa sele nakong ea tlhahiso ea protheine.
Mefuta ea RNA e Amehang
Ho na le mefuta e meraro e meholo ea RNA e amehang ka ho toba tlhahisong ea protheine: mRNA, tRNA, le rRNA. Kaofela tse tharo li sebetsa ka kopanelo ho fetolela tlhahisoleseling ho tsoa ho DNA ho ea tatellanong e nepahetseng ea amino acid.
1. mRNA (RNA ea lenģosa)
mRNA ke RNA ea lenģosa. Mosebetsi oa eona ke ho jara tlhahisoleseling ea liphatsa tsa lefutso ho tloha ho DNA ho ea ho li-ribosome, moo liprotheine li bokelloang teng. mRNA e na le tatellano ea li-codon, e leng lihlopha tsa metheo e meraro ea naetrojene, e 'ngoe le e 'ngoe e emela amino acid kapa lets'oao la ho emisa. Ka mantsoe a mang, mRNA ke "mongolo" oo li-ribosome li o balang ho bokella liprotheine.
Liseleng tsa eukaryotic, mRNA e sa tsoa thehoa e ntse e sebetsoa pele e tsoa khubung. Ts'ebetso ena e kenyelletsa ho eketsoa ha sekoahelo sa 5', ho eketsoa ha mohatla oa poly-A pheletsong ea 3', le ho kopanngoa ho tlosa li-intron le ho kopanya li-exons. Ts'ebetso ena e eketsa botsitso ba mRNA mme e netefatsa hore e ka fetoleloa ka nepo.
2. tRNA (phetisetso ea RNA)
tRNA e sebetsa e le "motsamaisi" oa li-amino acid ho ea ho ribosome. TRNA ka 'ngoe e na le anticodon, metheo e meraro e tlatsanang le codon ho mRNA. Ho feta moo, tRNA e na le amino acid e itseng pheletsong ea eona e 'ngoe. Ha anticodon e kopana le codon e tsamaellanang ho ribosome, tRNA e beha amino acid eo e e jereng ka har'a ketane ea polypeptide e ntseng e hola.
Ho nepahala ha tRNA ho jareng li-amino acid ho bohlokoa haholo. Ts'ebetso ena e thusoa ke enzyme aminoacyl-tRNA synthetase, e "jarang" tRNA ka li-amino acid tse nepahetseng. Haeba ho hlaha phoso, protheine e hlahang e ka ba le sebopeho le ts'ebetso e sa tloaelehang.
3. rRNA (ribosomal RNA)
rRNA ke karolo ea bohlokoa ea li-ribosome, e leng li-organelle moo tlhahiso ea protheine e etsahalang teng. Li-ribosome li entsoe ka liprotheine tsa rRNA le ribosomal. rRNA ha e sebetse feela e le moralo oa sebopeho sa li-ribosome empa hape e na le bokhoni ba ho etsa li-catalytic. Libopuoeng tse ngata, rRNA e sebetsa e le ribozyme, RNA e ka potlakisang liketso tsa lik'hemik'hale. Ho qaptjoeng ha protheine, rRNA e thusa ho thehoeng ha litlamo tsa peptide pakeng tsa li-amino acid, e leng mohato oa bohlokoa ho thehoeng ha protheine.
Mokhahlelo oa ho Ngola: Ho thehoa ha mRNA ho tsoa ho DNA
Ho kopanngoa ha protheine ho qala ka ho ngolwa ha tlhahisoleseding ya DNA ho mRNA. Ho ngolwa ha enzyme ho etsahala ha RNA polymerase e kgomarela ho promoter ho DNA, ebe e lokolla DNA helix mme e kopanya ketane ya RNA ho latela ho kopanya motheo ho tlatsanang. Haeba DNA e na le motheo wa A, RNA e tla eketsa U; haeba DNA e na le motheo wa T, RNA e tla eketsa A; C le G, mme ka tsela e fapaneng.
Phetolelo e hlahisa pre-mRNA ka har'a li-eukaryote, ebe e sebetsoa ho ba mRNA e hōlileng tsebong. Hang ha ts'ebetso e phethetsoe, mRNA e tsoa khubung ka masoba a nyutlelie 'me e kena cytoplasm, moo li-ribosome li leng teng.
Mokhahlelo oa Phetolelo: Ho fetolela mRNA ho Protheine
Hang ha mRNA e le ka har'a cytoplasm, ts'ebetso ea phetolelo ea qala. Phetolelo e etsahala ka har'a ribosome 'me e na le mekhahlelo e meraro e meholo: ho qala, ho lelefatsa le ho fela. Nakong ea mohato oa ho qala, ribosome e lemoha mRNA 'me e batla codon ea ho qala (hangata AUG), e leng se bontšang ho qala ha tlhahiso ea protheine. Codon ea AUG e boetse e fana ka khoutu ea amino acid methionine, kahoo methionine hangata ke amino acid ea pele ka har'a ketane ea polypeptide.
Nakong ea mohato oa ho lelefatsa, ribosome e tsamaea ho latela mRNA, e bala li-codon ka bonngoe. TRNA e loketseng e kena ka har'a ribosome, e jere amino acid e nepahetseng. Ebe ribosome e theha tlamo ea peptide pakeng tsa amino acid e ncha le ketane ea polypeptide e ntseng e hola. Ts'ebetso ena ea pheta, e lelefatsa ketane ea polypeptide ho latela tatellano ea li-codon tsa mRNA.
Mokhahlelo oa ho qetela ke ho fela ha motsoako, e leng se etsahalang ha ribosome e kopana le codon ea ho emisa (UAA, UAG, kapa UGA). Codon ea ho emisa ha e fane ka amino acid, empa e fana ka letšoao la ho fela ha phetolelo. Lintho tse felisang motsoako li thusa ho lokolla ketane ea polypeptide ho ribosome. Joale polypeptide e mena ka sebopeho sa mahlakore a mararo 'me e ka fetoloa kamora phetolelo hore e be protheine e sebetsang.
Karolo ea Li-RNA Tse Ling Taolong ea Ts'ebetso ea Protheine
Ntle le mRNA, tRNA, le rRNA, ho na le mefuta e meng ea RNA e bapalang karolo e sa tobang empa e le ea bohlokoa ho laoleng tlhahiso ea protheine, joalo ka miRNA (microRNA) le siRNA (RNA e nyane e sitisang). Li-RNA tsena tse nyane li ka khomarela mRNA 'me tsa thibela phetolelo kapa tsa baka ho senyeha ha eona. Kahoo, lisele li ka laola hore na protheine e itseng e hlahisoa neng le hore na e ngata hakae. Taolo ena e bohlokoa bakeng sa nts'etsopele ea lintho tse phelang, karabelo ea khatello ea maikutlo, le ho thibela tlhahiso ea protheine e sa hlokahaleng.
Bohlokoa ba RNA Bakeng sa Bophelo
Karolo ea RNA tlhahisong ea protheine e etsa hore molek'hule ena e be karolo ea bohlokoa ea bophelo. RNA ha se feela mokena-lipakeng ea sa sebetseng, empa hape ke sebapali se mafolofolo, se netefatsang phetolelo e nepahetseng le e sebetsang ea tlhahisoleseling ea liphatsa tsa lefutso. Ka tšebelisano-'moho ea mRNA, e jereng melaetsa, tRNA, e tsamaisang li-amino acid, le rRNA, e etsang setsi sa li-ribosome, lisele li khona ho hlahisa liprotheine tse hlokahalang bakeng sa mesebetsi eohle ea baeloji.
Ho feta moo, ho sibolloa ha li-RNA tse laolang tse kang li-miRNA ho atolositse kutloisiso ea rona ea hore RNA e boetse e bapala karolo ea ho laola tlhahiso ea liphatsa tsa lefutso, eseng feela ho kopitsa le ho fetolela tlhahisoleseling. Theknolojing ea baeloji le bongaka, ho utloisisa RNA ho tsamaisitse nts'etsopele ea mekhoa ea phekolo e thehiloeng ho RNA, ho kenyeletsoa liente tsa mRNA le mekhoa ea ho khutsisa liphatsa tsa lefutso ho sebelisoa tšitiso ea RNA.
Qetello
RNA e bapala karolo ea bohlokoa tlhahisong ea protheine, ho tloha ho ngoleng tlhahisoleseling ea DNA ka phetolelo ho ea ho fetoleng khoutu ea liphatsa tsa lefutso ka phetolelo. mRNA e jara molaetsa oa liphatsa tsa lefutso, tRNA e netefatsa hore li-amino acid tse nepahetseng li isoa ribosome, 'me rRNA ke karolo ea sebopeho le catalytic ea ribosome. Hammoho, RNA e nolofalletsa ho thehoa ha liprotheine ka nepo ho latela litaelo tsa liphatsa tsa lefutso. Kahoo, RNA ke e 'ngoe ea marokho a bohlokoa pakeng tsa tlhahisoleseling ea liphatsa tsa lefutso le mosebetsi oa baeloji, e leng se etsang hore e be ntlha ea bohlokoa baelojing ea limolek'hule ea sejoale-joale.
