DNA qauv tso cai rau nws rov ua dua li cas?
DNA qauv tso cai rau nws rov ua dua li cas?

Video: DNA qauv tso cai rau nws rov ua dua li cas?

Video: DNA qauv tso cai rau nws rov ua dua li cas?
Video: Tshuaj theem vim li cas thiaj tau nqi ?/ Siv kho mob dab tsi?/paris polyphylla use for? 2024, Kaum ib hlis
Anonim

DNA ua tau rov ua dua nws tus kheej vim yog txoj kev nws ob txoj hlua cuam tshuam rau ib leeg. Cov purines thiab pyrimidines uas koom nrog ob txoj hlua khi tshwj xeeb nrog rau lwm lub hauv paus. Qhov no xyuas kom meej tias thaum lub DNA strands cais rau rov ua dua tsim ib daim qauv tseeb.

Tsis tas li ntawd, tus qauv ntawm DNA tso cai rau qhov tseeb replication li cas?

DNA replication tshwm sim los ntawm kev pab ntawm ob peb enzymes. Cov enzymes "unzip" DNA molecules los ntawm rhuav cov hydrogen bonds uas tuav ob strands ua ke. Txhua strand ces ua ib tug qauv rau ib tug tshiab complementary strand yuav tsum tau tsim. Complementary bases txuas rau ib leeg (A-T thiab C-G).

Tsis tas li ntawd, tus qauv ntawm DNA tso cai rau nws kom luam cov ntawv xeem li cas? DNA yog ua los ntawm ob qho ntxiv strands thst yog iav dluab ntawm ib leeg. THAUM DNA replication lub cell yuav tsum tau ua ib qho ntxiv luam ntawm DNA vim cell yuav muab faib ua ob. Ib zaug cais muaj yog 2 cov ntawv luam ntawm DNA - "laus" strand & ib "tshiab" strand.

Tsuas yog li ntawd, vim li cas cov qauv ntawm DNA tseem ceeb rau kev rov ua dua?

Kev paub txog DNA tus qauv pab cov kws tshawb fawb to taub li cas DNA replicates. DNA replication yog tus txheej txheem uas DNA yog theej. Qhov no nthuav tawm cov hauv paus hauv cov molecule kom lawv tuaj yeem "nyeem" los ntawm lwm cov enzyme, DNA polymerase, thiab siv los tsim ob qho tshiab DNA strands nrog complementary bases, kuj los ntawm DNA polymerase.

Tus qauv ntawm DNA replication yog dab tsi?

DNA yog ua los ntawm ib tug ob helix ntawm ob complementary strands. Thaum rov ua dua , cov strands no sib cais. Txhua strand ntawm tus thawj DNA molecule ces ua tus qauv rau kev tsim khoom ntawm nws cov counterpart, txheej txheem hu ua semiconservative rov ua dua.

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