Dab tsi yog lacI hauv lac operon?
Dab tsi yog lacI hauv lac operon?

Video: Dab tsi yog lacI hauv lac operon?

Video: Dab tsi yog lacI hauv lac operon?
Video: СКОЛЬКО ДОЛЖНА БЫТЬ КЛЕТКА ДЛЯ ПТИЦ - Схема клетки 2024, Kaum ib hlis
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Tus yuam sij rau kev tswj cov ua haujlwm yog DNA-binding protein hu ua lac tus neeg ntxeev siab ( LacI ), qhia rau sab laug. Hauv qhov tsis muaj lactose , LacI inhibits kev qhia ntawm cov ua haujlwm los ntawm kev khi rau ob ntawm peb qhov chaw neeg teb xov tooj thiab ua rau DNA ntawm cov chaw sib khi mus rau hauv ib lub voj.

Ntawm no, yog LacI ib feem ntawm lac operon?

Lub gene uas encodes lub lac repressor npe lacI , thiab nyob rau hauv kev tswj ntawm nws tus kheej txhawb nqa. Cov lacI gene tshwm sim kom pom nyob ze ntawm lac operon ua , tab sis nws tsis yog ib ib feem ntawm ua haujlwm thiab qhia nyias. Thaum twg lactose yog tsis muaj, cov lac repressor khi nruj nreem rau tus neeg teb xov tooj.

Tsis tas li ntawd, lac operon hauv E coli yog dab tsi? Cov lac operon ua (Lactose ua haujlwm ) yog ib ua haujlwm xav tau rau kev thauj thiab metabolism ntawm lactose nyob rau hauv Escherichia coli thiab ntau lwm yam enteric kab mob . Cov noob khoom ntawm lacZ yog β-galactosidase uas cleaves lactose, disaccharide, rau hauv qabzib thiab galactose.

Ua li no, lac operon yog dab tsi thiab nws ua haujlwm li cas?

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 tom qab ntawd siv los ua kom muaj zog.

Lac Y ua dab tsi?

Lub duo tau sau tseg tias lac operon muaj peb lub noob uas encode cov proteins koom nrog hauv lactose metabolism. Cov no yog hu ua lac z, lac y, thiab lac a. Lub lac z gene encodes beta-galactosidase, lub lac y noob encodes ib permease, thiab lub lac a gene encodes transacetylase enzyme.

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