Qhov sib txawv tseem ceeb ntawm kev sau ntawv thiab kev txhais lus yog qhov kev txhais lus yog hais txog cov txheej txheem ntawm kev tsim mRNA molecule rau DNA ntawm ib lub noob thaum kev txhais lus yog hais txog cov txheej txheem ntawm kev sib txuas ntawm cov amino acid ib ntus los ntawm cov mRNA molecule transcribed.
Genes yog cov chav nyob ntawm caj ces. Tsuas yog lawv yog cov seem ntawm DNA. Lawv muaj cov ntaub ntawv keeb kwm (genetic code) los ua cov protein. Txhawm rau tsim cov protein, lawv tau txais kev qhia gene. Yog li ntawd, gene qhia yog cov txheej txheem ntawm synthesizing ib tug protein molecule (gene product) los ntawm cov genetic ntaub ntawv muab zais rau hauv cov noob. Gene qhia tshwm sim ntawm ob kauj ruam loj xws li kev sau thiab txhais lus. Kev txhais lus yog thawj kauj ruam, thiab nws tau ua raws li kev txhais lus, uas yog kauj ruam thib ob ntawm cov noob caj noob ces.
Kev txhais lus yog dab tsi?
Kev txhais lus yog thawj kauj ruam ntawm cov noob qhia. Nws yog cov txheej txheem ntawm kev tsim mRNA molecule los ntawm DNA qauv. Transcription tshwm sim nyob rau hauv lub nucleus ntawm eukaryotes. Nws yog ib qho enzyme-catalyzed cov tshuaj tiv thaiv. RNA polymerase yog lub enzyme uas catalyzes cov txheej txheem no. Ntawm ob txoj kab ntawm DNA hauv ib lub noob, ib qho ua haujlwm raws li cov txheej txheem coding thaum lwm qhov yog qhov tsis-coding sequence.
Tsis yog-coding ib ntus ua tus qauv hauv cov ntawv sau vim nws ua tiav rau cov txheej txheem coding. RNA polymerase enzyme nyeem cov nucleotides ntawm cov txheej txheem coding thiab ntxiv cov ribonucleotides kom raug thiab tsim cov mRNA molecule, uas muaj cov noob caj noob ces ntawm cov txheej txheem coding. Li no, qhov tshwm sim mRNA ib ntus dhau los ua tib yam rau cov txheej txheem coding. Txawm li cas los xij, vim nws yog RNA ib ntus, RNA polymerase ntxiv uracil es tsis txhob thymine thaum lub sijhawm sau ntawv.
Daim duab 01: Kev txhais lus
Hauv prokaryotes, tsuas yog ib hom RNA polymerase catalyzes cov ntawv sau. Tab sis hauv eukaryotes, peb hom RNA polymerases (I, II thiab II) ua cov ntawv sau. Tsis tas li ntawd, qhov kev txhawb nqa ib ntus yog qhov tseem ceeb los pib qhov kev sau thiab cov ntawv sau tseg thaum RNA polymerase ua tau raws li cov txheej txheem terminator.
Kev txhais lus yog dab tsi?
Kev txhais lus yog kauj ruam thib ob ntawm cov noob qhia. Ntxiv mus, nws yog cov txheej txheem ntawm kev hloov mRNA molecule rau hauv cov amino acid sib lawv liag ntawm cov protein. Nws tshwm sim nyob rau hauv lub cell organelle hu ua ribosomes tam sim no nyob rau hauv lub cytoplasm ntawm lub cell. Cov ntaub ntawv keeb kwm zais zais hauv mRNA molecule yog qhov kev txiav txim ntawm cov amino acid ib ntus ntawm cov protein uas codes los ntawm cov noob. Raws li txoj cai, peb nucleotides sib sau ua ib codon.
Daim duab 02: Kev txhais lus
Ib codon qhia txog cov amino acid tshwj xeeb tawm ntawm tag nrho ntawm 20 amino acids. Yog li, cov txheej txheem amino acid uas tau teev tseg yog tsim los ntawm mRNA molecule thaum lub sijhawm txhais lus. Ntxiv mus, kev txhais lus tshwm sim ntawm peb theem uas yog pib, elongation thiab xaus. Thaum kawg ntawm lub sijhawm txiav tawm, ribosome tso tawm peptide saw ntawm cov protein.
Dab tsi yog qhov zoo sib xws ntawm Kev Tshaj Tawm thiab Kev Txhais Lus?
- Kev txhais lus thiab txhais lus yog cov kauj ruam tseem ceeb ntawm kev qhia noob.
- mRNA cuam tshuam nrog ob txheej txheem.
- Tsis tas li, ob qho tib si zoo ib yam tseem ceeb rau kev tsim cov protein.
- Tsis tas li ntawd, ob qhov txheej txheem muaj peb theem loj.
- Ntxiv mus, ob txoj kev xav tau tus qauv los pib.
Qhov txawv ntawm Kev Txhais Lus thiab Kev Txhais Lus yog dab tsi?
Kev txhais lus thiab txhais lus yog ob kauj ruam sib txawv ntawm cov noob qhia. Peb tuaj yeem txheeb xyuas qhov sib txawv ntawm kev hloov pauv thiab kev txhais lus raws li ntau yam xws li tus qauv, cov khoom siv raw, qhov chaw, cov khoom, cov enzymes koom nrog, thiab lwm yam. Feem ntau, kev hloov pauv yog tus txheej txheem ntawm kev tsim cov mRNA molecule los ntawm DNA qauv ntawm cov noob. Ntawm qhov tod tes, kev txhais lus yog cov txheej txheem ntawm kev tsim cov amino acid ib ntus ntawm cov protein los ntawm mRNA molecule. Yog li ntawd, qhov no yog qhov sib txawv tseem ceeb ntawm kev sau thiab txhais lus.
Tsis tas li ntawd, raws li cov khoom siv raw, qhov sib txawv ntawm kev sau ntawv thiab kev txhais lus yog qhov kev hloov pauv yuav tsum muaj plaub hom ribonucleotides raws li nws cov ntaub ntawv raw thaum txhais lus xav tau 20 txawv amino acids raws li nws cov ntaub ntawv raw. Ib yam li ntawd, transcription tshwm sim nyob rau hauv lub nucleus thaum txhais lus tshwm sim nyob rau hauv lub ribosomes. Li no, qhov no yog qhov sib txawv ntawm kev sau ntawv thiab kev txhais lus hauv kev sib raug zoo rau qhov chaw ntawm qhov tshwm sim. Ntau qhov sib txawv ntawm kev sau ntawv thiab kev txhais lus muaj nyob hauv cov ntawv hauv qab no.
Summary – Transcription vs Translation
Kev txhais thiab txhais lus yog ob kauj ruam tseem ceeb ntawm cov txheej txheem gene. Kev txhais lus yog ua raws li kev txhais lus. Hauv lwm lo lus, kev txhais lus siv cov khoom ntawm cov ntawv sau. Yog li ntawd, tshwj tsis yog tias ob qho tib si cov kauj ruam no ua tiav, cov txheej txheem gene qhia tseem tsis tiav. Thaum lub sij hawm transcription, cov ntaub ntawv nyob rau hauv lub coding ib theem zuj zus hloov mus rau hauv ib tug mRNA molecule thaum lub sij hawm lub sij hawm lub sij hawm ntawm kev txhais lus, codons nyob rau hauv lub mRNA molecule hloov mus rau hauv ib tug amino acid ib theem zuj zus ntawm ib tug protein. Qhov no yog qhov sib txawv loj ntawm kev sau thiab txhais lus. Tsis tas li ntawd, kev hloov pauv tshwm sim hauv cov nucleus ntawm eukaryotes thaum transcription tshwm sim hauv cytoplasm txuam nrog ribosomes.
