This document discusses DNA replication and the role of various enzymes in the process. It then summarizes two scientific articles about research on DNA breakage and cancer development. The first article describes research from Hebrew University scientists that identified the molecular basis for DNA breakage. The second discusses proteins called Cks1 and Cks2 that allow cancer development by overriding checkpoints during cell division. The document concludes that these discoveries may help develop new cancer treatments and prevention strategies by targeting these proteins or DNA breakage processes early in cancer development.

1. DNA REPLICATIONUniversidad Pontificia BolivarianaMaría Paulina Henao ZuluagaMedicine Student3rd Semester

4. INTRODUCTIONAn essential property of the genetic material is its ability to make exact copies of itself.DIRECTION5’---- 3’ENZYMES DNA Polymerases,

5. DNA Ligase

6. Primase

7. SSDPB (Single Strand DNA BindingProtein)

8. Topoisomerases,

9. RNAse- HHEBREW U. SCIENTISTS IDENTIFY MOLECULAR BASIS FOR DNA BREAKAGEBIOLOGY & NATURE(July 19, 2011)

10. HEBREW U. SCIENTISTS IDENTIFY MOLECULAR BASIS FOR DNA BREAKAGE

11. HEBREW U. SCIENTISTS IDENTIFY MOLECULAR BASIS FOR DNA BREAKAGEThe cell increase proliferation processCANCER“FRAGILE SITES “ are created in the early cancer stages Later cells enters in stress on DNA replicationDiscover bases of DNA breakage

12. HEBREW U. SCIENTISTS IDENTIFY MOLECULAR BASIS FOR DNA BREAKAGE

13. OBSERVATION

14. SCIENTISTS FIND 'BRAKE-OVERRIDE' PROTEINS THAT ENABLE DEVELOPMENT OF SOME CANCERS BIOLOGY & NATURE(July 7, 2011)

15. SCIENTISTS FIND 'BRAKE-OVERRIDE' PROTEINS THAT ENABLE DEVELOPMENT OF SOME CANCERSIn normal conditions

16. SCIENTISTS FIND 'BRAKE-OVERRIDE' PROTEINS THAT ENABLE DEVELOPMENT OF SOME CANCERSUncontrolled and excessiveproliferation

17. SCIENTISTS FIND 'BRAKE-OVERRIDE' PROTEINS THAT ENABLE DEVELOPMENT OF SOME CANCERSCks 1 and Cks 2 proteins Avoid the checkpoint in the STAGE ”S” Cells continuous playback with the damaged genome

18. OBSERVATION

19. MEDICAL UTILITY

20. MEDICAL UTILITYWith the discovery of protein function Cks1 and Cks2 may be finding new ways of treatment and prevention against cancer by preventing the large increase of these in the early stages of disease development, improving the quality of life for thousands of people.

21. MEDICAL UTILITYWith the discovery of the molecular basis of DNA breakage, are disclosed new features of the structure of DNA that promote the development of cancer, identifying the initial cancer processes such as fragile sites. This can be used to prevent cancer development through genetic modification.

22. MEDICAL UTILITYAll these studies that realize about the operation, structure and application of DNA, serve as the basis for many other studies and provide valuable information in front of a cure for some diseases that affect millions of people such as cancer. Those discovers help to preserve the quality of life and the people.

23. BIBLIOGRAFHYScientistsfind “brake-override” proteinsthatenabledevelopment of somecancers.URL:http://esciencenews.com/articles/2011/07/07/scientists.find.brake.override.proteins.enable.development.some.cancers .(Biology& Nature). MARTINEZ SÁNCHEZ, Lina María. Biología molecular. 2. ed. Medellín: UPB. Fac. de Medicina, 2006. 208 p.HebrewU. scientistsidentify molecular basisfor DNA breakage. URL: http://esciencenews.com/articles/2011/07/19/hebrew.u.scientists.identify.molecular.basis.dna.breakage. (Biology & Nature) .

24. THANKS