2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
Cov ntaub ntawv caj ces nqa hauv codons ntawm mRNA tam sim no tau nyeem (decoded) los ntawm anticodons ntawm tRNA. Raws li txhua tus codon (triplet) tau nyeem, cov amino acids tau koom ua ke kom txog thaum lub codon nres (UAG, UGA lossis UAA) mus txog. Lub sijhawm no, polypeptide (protein) tau raug tsim tawm thiab raug tso tawm.
Yuav ua li cas thaum hloov pauv hloov pauv tshwm sim?
Frameshift Mutation
Txhua pawg ntawm peb lub hauv paus sib raug rau ib qho ntawm 20 cov amino acids sib txawv siv los tsim cov protein. Yog tias kev hloov pauv cuam tshuam qhov kev nyeem ntawv no, ces tag nrho DNA kab ke tom qab kev hloov pauv yuav raug nyeem tsis raug.
Puas tau hloov pauv hloov pauv ua rau ntxov ntxov nres codons?
Frameshift kev hloov pauv yog kev tshem tawm lossis ntxiv ntawm 1, 2, lossis 4 nucleotides uas hloov cov ribosome nyeem ntawv thiab ua rau kev txiav tawm ntxov ntawm kev txhais lus ntawm qhov tsis muaj tseeb tshiab lossis cov saw txiav tawm codon (TAA, TAG, thiab TGA).
frameshift mutation hloov codons li cas?
Frameshift kev hloov pauv yog qhov tshwm sim ntawm kev ntxig lossis tshem tawm uas hloov cov kab ntawv nyeem ntawm triplet codons, yog li hloov pauv kev txhais lus thiab hloov cov qauv thiab kev ua haujlwm ntawm cov khoom lag luam protein.
Dab tsi yog lub ntsiab lus ntawm kev hloov pauv hloov pauv?
Ib qho kev hloov pauv tau tshwm sim los ntawm kev ntxig lossis tshem tawm ntawm tus lej ntawm nucleotides uas tsis yog ntau ntawm peb. CovKev hloov pauv hauv kev nyeem ntawv hloov pauv txhua cov amino acid tom qab qhov kev hloov pauv thiab ua rau cov protein tsis ua haujlwm.
Pom zoo:
Puas yog qhov hloov pauv tau thaum lub sijhawm muaj kev hloov pauv?
Kev hloov pauv hloov pauv hloov pauv kev lag luamthiab yog li hloov lub ntiaj teb. Txhua qhov kev tsim kho tshiab uas tawm los ntawm kev hloov pauv kev lag luam tau txais txiaj ntsig los ntawm kev sib hloov pauv, lub tshuab nqus tsev, tshuab xaws, xov tooj, thiab ntau dua.
Dab tsi yog qhov hloov pauv thiab hloov pauv hloov pauv?
Point mutations hloov ib leeg nucleotide. Frameshift kev hloov pauv yog ntxiv lossis tshem tawm ntawm nucleotides uas ua rau muaj kev hloov pauv hauv kev nyeem ntawv. frameshift thiab point mutation yog dab tsi? Ib qho kev hloov pauv cuam tshuam rau ib khub hauv paus.
Qhov kev hloov pauv no puas yuav ua rau muaj kev hloov pauv hloov pauv?
Yog li, yog tias muaj kev hloov pauv, piv txwv li, kev ntxig lossis tshem tawm ntawm nucleotide, tshwm sim, qhov no tuaj yeem ua rau kev hloov pauv ntawm kev nyeem ntawv. Nws hloov tag nrho cov amino acid ib ntus. Cov kev hloov pauv no yog hu ua frameshift mutation (tseem hu ua kev nyeem ntawv hloov pauv, nyeem ntawv hloov pauv, lossis framing yuam kev).
Qhov twg yog qhov kev hloov pauv hloov pauv hloov pauv?
Semiconservative replication piav qhia txog cov txheej txheem ntawm DNA replication nyob rau hauv tag nrho cov paub hlwb. DNA replication tshwm sim ntawm ntau lub hauv paus pib ntawm kev rov ua dua raws DNA qauv strand. Raws li DNA ob chav helix yog unwound by helicase, replication tshwm sim nyias ntawm txhua tus qauv strand nyob rau hauv antiparallel cov lus qhia.
Qhov kev hloov pauv twg yog xav tias yuav cuam tshuam los ntawm kev hloov pauv hloov pauv?
Dependent Variable Qhov sib txawv uas nyob ntawm lwm yam uas ntsuas. Cov kev hloov pauv no yuav tsum tau hloov pauv raws li qhov kev sim ua haujlwm ntawm tus kheej hloov pauv lossis hloov pauv. Nws yog cov nyhuv presumed. Qhov kev tshawb fawb hloov pauv twg yog qhov tshwm sim?
