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DNA replication

DNA replication. Central dogma of molecular biology. 1.the basic principle of DNA replication. Semiconservative replication. a. concept evidence conclusion. (2) Semidiscontinuous replication. * The synthesis direction of DNA polymerase.

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DNA replication

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  1. DNA replication Central dogma of molecular biology

  2. 1.the basic principle of DNA replication • Semiconservative • replication

  3. a. concept • evidence • conclusion

  4. (2) Semidiscontinuous replication * The synthesis direction of DNA polymerase * leading strand & lagging strand

  5. * Okazaki fragment (3) RNA primer * the synthesis * the function

  6. (4) fidelity 2. Enzymes & proteins cooperate in the DNA replication

  7. E.coli DNA polymerase I • (Kornberg enzyme,DNA-Directed • DNA polymerase,DDDP,pol I )

  8. * The principle materials for pol I # four dNTP # Mg 2+ # RNA primer or DNA single strand possessed 3’-OH # DNA template

  9. * Multiple function of pol I Klenow fragment------- (large fragment) DNA polymerase activity, 3’-5’ exonuclease activity small fragment------- 5’-3’ exonuclease activity

  10. pol I 5’ 3’ 3’ 5’ exonuclease exonuclease DNA polymerase activity activity activity Small fragmentlarge fragment (Klenow fragment) Proofreading

  11. * the principle materials for pol II & pol III # four dNTP # Mg 2+ # RNA primer or DNA single strand possessed 3’-OH # DNA template

  12. * the characteristics of pol II & pol III pol II---mostly concerned with proofreading & DNA repair pol III---- indispensable for DNA replication,the highest rate of chain elongation and processive

  13. (2) DNA polymerase in eukaryocyte polymerase : gap filling & synthesis of lagging strand : DNA proofreading & repair : DNA repair : mitochondria DNA synthesis : processive,leading strand synthesis, need the assistance of PCNA

  14. (3) helicase & gyrase a. helicase * function * require b. single strand binding protein (SSB) ,helix disabling protein,HDP

  15. * function • topoisomerase I • * function • d. topoisomerase II, gyrase • * function

  16. Primosome • DNA ligase • * function • * require • * process

  17. * characteristics * usage 3.procedure of DNA replication • the initiation of the • replication

  18. * the origin of replication ---- The special structure (ori C) * the process of initiation formation of replication fork ( replication bubbles)

  19. (2) the elongation of the replication * how to deal with synthesis direct ? (3) the termination of the replication

  20. *Removes primers---- pol I small fragment * fills the gap with dNTP----- pol I large fragment (Klenow fragment) *ligation----DNAligase

  21. 4. Summarize of DNA replication a.identification of the origin of replication b.unwinding (denature)of ds DNA to provide ssDNA c. formation of replication fork d.initiation of DNA synthesis & elongation

  22. e. formation of replication bubbles with ligation of the newly synthesized DNA segment f. Reconstitution of chromatin DNA

  23. Telomere & telomerase • (1) telomere • *concept • *structure • * function

  24. The function & molecular • components of telomerase • * function • * components (RNP) • * mechanism

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