Lipotso tsa Mehlala mabapi le DNA le Liphatsa tsa Lefutso
Pendahuluan
Ho baeloji ea limolek'hule, DNA (Deoxyribonucleic Acid) le liphatsa tsa lefutso ke likhopolo tsa motheo tse tšehetsang kutloisiso ea lefa la litšobotsi le ts'ebetso ea lintho tse phelang. DNA ke molek'hule e bolokang tlhahisoleseling eohle ea liphatsa tsa lefutso e hlokahalang ho laola sebopeho le ts'ebetso ea sebopuoa. Ka lehlakoreng le leng, liphatsa tsa lefutso ke likarolo tsa DNA tse ngolang liprotheine tse itseng kapa RNA. Ho utloisisa DNA le liphatsa tsa lefutso ho bohlokoa ho mang kapa mang ea nang le thahasello baelojing, baeloji, bongaka le masimo a amanang le eona. Sengoloa sena se tla tšohla lipotso tse ling tse botsoang khafetsa tse amanang le lihlooho tsena, hammoho le litlhaloso tsa tsona.
1. Potso ea 1: Sebopeho sa DNA
Potso: Hlalosa sebopeho sa DNA sa helix e habeli 'me u bolele likarolo tse ka sehloohong tse e etsang.
Puisano: DNA ke helix e habeli, ho bolelang hore e na le likhoele tse peli tse phuthetsoeng, joalo ka litepisi tse potolohang. Sebopeho sena se ile sa hlahisoa ka lekhetlo la pele ke James Watson le Francis Crick ka 1953, ba ileng ba boela ba hapa Khau ea Nobel bakeng sa ho sibolloa ha bona. DNA e entsoe ka likarolo tse tharo tse kholo: phosphate, tsoekere ea deoxyribose, le metheo ea naetrojene. Metheo ena ea naetrojene ke adenine (A), thymine (T), cytosine (C), le guanine (G). Ho helix e habeli, metheo ena e kopana ka ho khetheha: Lipara tsa A tse nang le T ka har'a litlamo tse peli tsa hydrogen, le lipara tsa C tse nang le G ka har'a litlamo tse tharo tsa hydrogen. Lithapo tsa lere la DNA li emeloa ke tsoekere le phosphate, ha liphaephe li emeloa ke lipara tsa motheo.
2. Potso ea 2: Ho ikatisa ha DNA
Potso: Ho boleloa'ng ka ho pheta-pheta ha DNA ka mokhoa o sa fetoheng, hona ke hobane'ng ha ho le bohlokoa?
Puisano: Ho pheta-pheta ha DNA ka mokhoa oa semiconservative ke mokhoa oo molek'hule e 'ngoe le e 'ngoe e ncha ea DNA e nang le khoele e le 'ngoe ea pele le khoele e le 'ngoe e ncha. Ha DNA e ipheta, helix e habeli e phutholoha joaloka zipper, 'me khoele e 'ngoe le e 'ngoe ea pele e sebetsa e le mohlala oa ho kopanya khoele e ncha. Ts'ebetso ena ea bohlokoa hobane e netefatsa hore sele e 'ngoe le e 'ngoe ea morali e fumana khoele e le 'ngoe ea DNA e tšoanang le khoele ea pele, e boloka botšepehi ba tlhahisoleseling ea liphatsa tsa lefutso ho pholletsa le meloko. Ho pheta-pheta ha semiconservative ho thusa ho fokotsa liphoso nakong ea karohano ea sele 'me ho bohlokoa bakeng sa lefa le nepahetseng la liphatsa tsa lefutso.
3. Potso ea 3: Tlhaloso ea liphatsa tsa lefutso
Potso: Mekhoa ea ho ngola le ho fetolela e etsahala joang polelong ea liphatsa tsa lefutso?
Puisano: Ponahalo ea liphatsa tsa lefutso e kenyelletsa mekhahlelo e 'meli e meholo: phetolelo le phetolelo. Phetolelong, karolo ea DNA e nang le liphatsa tsa lefutso tse itseng e sebelisoa e le mohlala oa ho kopanya RNA ea moromuoa (mRNA). Ts'ebetso ena e etsahala ka har'a nucleus ea sele 'me e kenyelletsa enzyme RNA polymerase, e tlamang ho DNA le ho kopanya mRNA ho latela tatellano ea motheo oa DNA. Kamora phetolelo, mRNA e tloha nucleus 'me e ea ho li-ribosomes tse cytoplasm, moo phetolelo e etsahalang teng.
Nakong ea phetolelo, li-ribosome li bala tatellano ea motheo ea mRNA ka lihlopha tsa tse tharo tse bitsoang li-codon. Codon ka 'ngoe e ikhethile bakeng sa amino acid e itseng. RNA ea phetisetso (tRNA) e jara li-amino acid tse tsamaellanang ho ea ho ribosome, ebe e li kopanya ka har'a ketane ea polypeptide ho latela tatellano ea codon. Hang ha ketane ea polypeptide e phethehile, e etsoa ts'ebetso e 'ngoe ho ba protheine e sebetsang e bapalang karolo ea bohlokoa sele.
4. Potso ea 4: Phetoho ea Liphatsa tsa Lefutso
Potso: Ho boleloa'ng ka phetoho ea liphatsa tsa lefutso, 'me liphetoho tsa liphatsa tsa lefutso li ka ama lintho tse phelang joang?
Puisano: Liphetoho tsa lefutso ke liphetoho tatellanong ea motheo ea DNA. Liphetoho tsena li ka etsahala ka tšohanyetso nakong ea ho ikatisa ha DNA kapa tsa bakoa ke mabaka a kantle a kang mahlaseli le lik'hemik'hale tsa phetoho. Liphetoho tsa lefutso li ka ama lintho tse phelang ka litsela tse fapaneng, ho latela mofuta le sebaka sa phetoho.
Liphetoho tsa lefutso li ka aroloa ka mefuta e meraro e meholo:
– Liphetoho tsa lintlha: li kenyelletsa liphetoho ho nucleotide e le 'ngoe. Tsena li ka etsahala ka mokhoa oa ho nkeloa sebaka (ho nkela motheo o mong sebaka ka o mong), ho kenngoa, kapa ho tlosoa.
– Phetoho ea Missense: e fella ka ho nkeloa sebaka ha amino acid e le 'ngoe ka protheineng.
– Liphetoho tse se nang kelello: ho hlahisa li-codon tse emisang pele ho nako, ho emisa tlhahiso ea protheine kapele.
– Liphetoho tsa Frameshift: tse bakoang ke ho kenngoa kapa ho hlakoloa ho fetolang foreimi ea ho bala ea mRNA.
Tšusumetso ea liphetoho tsa lefutso e ka fapana. Liphetoho tse ling tsa lefutso ha li na phello (liphetoho tse khutsitseng), ha tse ling li ka sitisa ts'ebetso ea protheine, tsa baka mafu a liphatsa tsa lefutso, kapa, maemong a sa tloaelehang, tsa fana ka monyetla oa ho iphetola ha lintho.
5. Potso ea 5: Tšebeliso ea Biotechnology le Recombinant DNA
Potso: Hlalosa kamoo theknoloji ea DNA e kopantsoeng e ka sebelisoang kateng ho nts'etsopele ea lijalo tse hanelang likokoanyana.
Puisano: Theknoloji ea DNA e kopantsoeng e kenyelletsa ho kopanya liphatsa tsa lefutso tse tsoang linthong tse fapaneng ho hlahisa lintho tse phelang tse nang le litšobotsi tse ncha, tse lakatsehang. Nts'etsopele ea lijalo tse hanelang likokoanyana, liphatsa tsa lefutso tse kenyang liprotheine tse bolaeang likokoanyana kapa tse thibelang kholo ea tsona li ka nkuoa ho tsoa libaktheria 'me tsa kenngoa ka har'a genome ea semela.
Mohlala, Bacillus thuringiensis (Bt) ke baktheria e hlahisang protheine e chefo ho likokoanyana tse itseng. Jini e kenyang protheine ea Bt e ka aroloa le ho kenngoa ka har'a DNA ea limela ho sebelisoa theknoloji ea DNA e kopantsoeng. Sejalo sa Bt se hlahisoang se hlahisa protheine ea sona 'me se ka itšireletsa litlhaselong tsa likokoanyana ntle le tlhoko ea chefo e eketsehileng ea lik'hemik'hale. Sena ha se eketse tlhahiso ea lijalo feela empa se boetse se fokotsa tšusumetso ea tikoloho ea tšebeliso ea chefo e bolaeang likokoanyana.
Ho koala
Ho utloisisa DNA le liphatsa tsa lefutso ha ho bohlokoa feela ho ba sebetsang baelojing le bongaka, empa hape le ho sechaba ka kakaretso, ka lebaka la bohlokoa ba eona ho theknoloji ea baeloji le maphelo a rona a letsatsi le letsatsi. Ka ho hlahloba mathata le lipuisano tsa mehlala, re tšepa hore sena se fana ka temohisiso e tebileng ka taba ena ea bohlokoa. Kea leboha ka ho latela, 'me re tšepa hore sena se bile thuso.
