Gene nthuav qhia hauv Prokaryotes vs Eukaryotes
Gene kev qhia yog txheej txheem tseem ceeb uas tshwm sim hauv ob qho tib si prokaryotes thiab eukaryotes. Txawm hais tias qhov tseeb tias cov txiaj ntsig ntawm ob qho tib si eukaryotes thiab prokaryotes yog tib yam, muaj qhov sib txawv ntawm lawv. Gene qhia tau hais txog feem ntau, thiab qhov sib txawv ntawm cov txheej txheem prokaryotic thiab eukaryotic tau qhia tshwj xeeb hauv kab lus no.
Gene Expression
Thaum cov ntaub ntawv ntawm cov noob tau hloov mus rau hauv cov qauv qauv, cov noob tshwj xeeb tau hais los qhia. Gene qhia yog ib qho txheej txheem uas ua rau cov roj ntsha tseem ceeb, thiab cov no feem ntau yog macromolecules. Genes feem ntau qhia nyob rau hauv daim ntawv ntawm cov proteins, tab sis RNA kuj yog ib yam khoom ntawm cov txheej txheem no. Yuav tsis muaj lub neej yam tsis muaj cov txheej txheem gene qhia tau tshwm sim.
Peb cov kauj ruam tseem ceeb muaj nyob rau hauv cov lus qhia noob hu ua transcription, RNA ua, thiab txhais lus. Cov post translations protein hloov thiab tsis-coding RNA maturation yog ib co ntawm lwm yam txheej txheem koom tes nrog gene qhia. Nyob rau hauv cov kauj ruam transcription, nucleotide ib theem zuj zus ntawm cov noob nyob rau hauv DNA strand yog transcribed rau hauv RNA tom qab DNA strand raug dismantled nrog DNA helicase enzyme. Cov tshiab tsim RNA strand (mRNA) yog hloov kho los ntawm kev tshem tawm cov tsis-coding sequences thiab noj cov nucleotide ib ntus ntawm cov noob mus rau ribosomes. Muaj cov tRNA tshwj xeeb (hloov RNA) molecules uas paub txog cov amino acids cuam tshuam hauv cytoplasm. Tom qab ntawd, tRNA molecules txuas nrog rau cov amino acids tshwj xeeb. Hauv txhua tRNA molecule, muaj ib ntu ntawm peb nucleotides. Ib qho ribosome nyob rau hauv cytoplasm yog txuas mus rau mRNA strand, thiab pib codon (tus txhawb nqa) raug txheeb xyuas. Cov tRNA molecules nrog cov nucleotides sib thooj rau mRNA ib ntus raug txav mus rau hauv lub subunit loj ntawm ribosome. Raws li tRNA molecules tuaj rau lub ribosome, cov amino acid sib raug zoo nrog cov amino acid tom ntej hauv cov kab ke los ntawm peptide daim ntawv cog lus. Qhov kev sib txuas ntawm peptide no txuas ntxiv mus txog thaum kawg codon nyeem ntawm ribosome. Raws li qhov sib lawv liag ntawm cov amino acids hauv cov saw hlau, cov duab thiab kev ua haujlwm sib txawv rau txhua qhov molecule protein. Cov duab thiab kev ua haujlwm no yog cov txiaj ntsig ntawm nucleotide ib ntus hauv DNA molecule. Li no, nws paub meej tias cov noob sib txawv sib txawv cov proteins nrog cov duab sib txawv thiab ua haujlwm.
Dab tsi yog qhov txawv ntawm Gene Expression hauv Prokaryotes thiab Eukaryotes?
• Txij li thaum prokaryotes tsis muaj lub hnab ntawv nuclear, cov ribosomes tuaj yeem pib tsim cov protein raws li mRNA strand tsim. Qhov no yog qhov sib txawv heev rau cov txheej txheem eukaryotic, qhov twg mRNA strand yuav tsum tau thauj mus rau hauv cytoplasm rau ribosomes rau kev sib raug zoo nrog qhov ntawd. Tsis tas li ntawd, tus naj npawb ntawm cov kauj ruam tseem ceeb yog ob qho hauv kev qhia cov noob prokaryotic, whereas muaj peb kauj ruam tseem ceeb hauv cov txheej txheem eukaryotic.
• Muaj intron sequences hauv eukaryotic DNA kom cov mRNA strand kuj muaj cov. Yog li, RNA splicing yuav tsum tau ua ua ntej ua tiav cov mRNA strand sab hauv lub nucleus hauv eukaryotes. Txawm li cas los xij, tsis muaj RNA ua cov kauj ruam hauv prokaryotes vim tsis muaj introns hauv lawv cov khoom siv caj ces.
• Muaj peev xwm nthuav qhia cov noob caj noob ces (hu ua operons) muaj nyob rau hauv cov txheej txheem prokaryotic. Txawm li cas los xij, tsuas yog ib qho qhia ib zaug hauv eukaryotes, thiab tom qab mRNA strand yog degraded tom qab qhia, ib yam nkaus.
