1. DNA: The Chemical Nature of the Gene Chapter 10

2. Chapter 10: Lecture Outline Historical perspective DNA structure RNA structure

3. Early historical perspective

4. We enter the 20 th century with an understanding of the DNA building block.

5. Some Experimental Data leading to DNA as biological source of DNA Griffith’s Avery et al. Hershey and Chase Chargaff Wilkins and Franklin Watson and Crick

6. Streptococcus pneumonia Smooth Strain Rough Strain

7. Griffith’s Experiment: 1928 Conclusion: A Transformation “factor” exists

8. 1944: Avery;MacLeod;McMarty Discovered tranforming principle as DNA Oswald Avery

9. Heat killed; homogenize and filter IIIS virulent bacteria Destroy either RNA; protein or DNA Add samples to non-virulent bacteria Only bacteria without IIIS DNA did not transform Avery, MacLeod & McCarty

10. August 20, 2003 Martha Chase dies: With Alfred D. Hershey, she established DNA as the genetic material | By Milly DawsonBy Milly Dawson 1908 — 1997 1930-2003

11. Support for nucleic acid transfer Hershey and Chase Experiment, 1952: Confirms DNA as genetic material

12. Conclusion: DNA identified as source of genetic information

13. At the same time amore detailed chemical Structure of DNA was also ongoing…

14. Franklin and Wilkins 1947 1920-1958 1916-2004

15. Chargaff’s Rule 1948 1905-2002

16. Watson and Crick, 1953 inferred the DNA structure

17. Nobel Prize: 1962 1928- 1916-2004

18. Fraenkel-Conrat 1956: RNA also carries genetic information VIRAL RNA

19. Tobacco Mosaic Virus

20. The Structure of Genetic Material

21. The building blocks of DNA are nucleotides.

23. RNA’s SugarDNA’s Sugar

24. Nitrogenous Bases

25. DNA nucleotides

26. Polarity and Anti-Parallel

27. Back to Franklin and Wilkins Data: Pairing of specific classes of bases can account for diameter of DNA Just right! 6 sided ring 6 sided ring + 5 sided ring

29. Most Common Secondary Structure (3D structure) B-DNA Alpha Helix Right Handed Turn 10 bases per 360º turn

30. A function of Major and Minor Grooves

31. DNA ’ Special structures Modifications

32. Integration of DNA and RNA

33. Central Dogma Information Transfer