Kev siv lac operon yog dab tsi?
Kev siv lac operon yog dab tsi?

Video: Kev siv lac operon yog dab tsi?

Video: Kev siv lac operon yog dab tsi?
Video: Siv Yis part 4 2024, Kaum ib hlis
Anonim

Cov lac , los yog lactose , ua haujlwm muaj nyob rau hauv E. coli thiab lwm yam kab mob enteric. Qhov no ua haujlwm muaj gene coding rau cov proteins nyob rau hauv tus nqi thauj lactose mus rau cytosol thiab zom nws mus rau hauv qabzib. Cov piam thaj no yog thaum ntawd siv ua kom muaj zog.

Tsis tas li ntawd, lub hom phiaj ntawm lac operon yog dab tsi?

Cov lac operon ua ( lactose ua haujlwm ) yog ib ua haujlwm xav tau rau kev thauj thiab metabolism ntawm lactose Hauv Escherichia coli thiab ntau lwm cov kab mob enteric. Cov noob khoom ntawm lacZ yog β-galactosidase uas cleaves lactose , disaccharide, rau hauv qabzib thiab galactose.

Tsis tas li ntawd, tib neeg puas muaj lac operon? Cov Tib neeg qhov project genome. Ib ua haujlwm Qhov tseem ceeb yog ib pawg ntawm cov noob lossis ib ntu ntawm DNA uas ua haujlwm qhia txog cov noob no. Cov neeg ua haujlwm yog feem ntau pom muaj nyob rau hauv cov kab mob prokaryotic cov kab mob xws li E. The lac operon ua yog tsim los ntawm kev txhawb nqa, kev tawm tsam, tus neeg teb xov tooj, thiab cov noob.

Ib yam li ntawd, koj tuaj yeem nug, CAP ua dab tsi hauv lac operon?

Thaum cov piam thaj hauv cov ntshav poob qis hauv lub cell, accumulating cAMP khi rau qhov zoo regulator catabolite activator protein ( CAP ), ib qho protein uas khi rau cov neeg txhawb nqa cov neeg ua haujlwm uas tswj cov txheej txheem ntawm lwm cov suab thaj, xws li cov lac operon ua . Cov CAP pab tsim khoom thaum tsis muaj piam thaj.

Puas yog lac operon zoo lossis tsis zoo?

Operaon kev cai yuav yog ib qho tsis zoo los yog zoo los ntawm induction los yog repression. Qhov no tso cai rau kev nthuav qhia ntawm cov ua haujlwm . Cov lac operon ua yog a tsis zoo tswj inducible ua haujlwm , qhov twg inducer molecule yog allolactose. Hauv tsis zoo tsim txom cov neeg ua haujlwm , transcription ntawm lub ua haujlwm ib txwm siv qhov chaw.

Pom zoo: