2. I. History of DNA A. Friedrich Miescher 1. Identified DNA in the nucleus of white blood cells in 1871 2. It was a sugary, phosphate-rich chemical which he called nuclein

3. B. Fredrick Griffith- The Transformation Experiment- 1928 1. British bacteriologist whose focus was on the epidemiology and pathology of bacterial pneumonia 2. His experimentation is now known as the transformation experiment 3. He showed that Streptococcus pneumoniae, could transform from one strain into a different strain 4. The transforming principle was later identified as DNA

5. C. Oswald Avery- DNA is the Genetic Material- 1944 1. The genetic information was thought to be contained in protein 2. Continuing the research done by Griffith in 1928, Avery worked with MacLeod and McCarty on the mystery of the transformation 3. His team made protein and DNA extracts of the capsulted strain (which has a smooth surface) and introduced the substance into a rough-surfaced type of bacterium 4. The rough-surfaced strain transformed into the smooth-surfaced type, he knew the substance he had extracted contained the gene that coded for the smooth surface 5. Avery published the results of his research in 1944. The paper led to more intensive studies of DNA, which eventually revealed it to be the common agent of heredity

7. D. Alfred Hershey and Martha Chase 1. “Waring Blender” Experiment 2. DNA is the Genetic Material- 1952

8. Food Blender Centrifuge

9. 32 35 DNA P Labeled Protein S Labeled

10. E. Erwin Chargaff – 1940’s 1. Chargaff's rules a. The amount of guanine is equal to cytosine and the amount of adenine is equal to thymine b. The composition of DNA varies from one species to another, in particular in the relative amounts of A, G, T, and C bases

11. F. Discovery of the Structure of DNA 1. James Watson and Francis Crick- 1953 a. Cambridge University 2. Maurice Wilkins and Rosalind Franklin a. Kings College

12. Photo 51 The Watson and Crick Model of the Structure of DNA

13. II. DNA Structure A. Double Helix

14. B. DNA Nucleotide C. Base Pairing

15. D. Purine and Pyrimidine Bases E. Antiparallel Nature of DNA

16. F. DNA Replication

17. G. Messelson and Stahl 1. DNA Replicates Semi-conservatively 2. Let E. coli replicate its DNA in Nitrogen- 15 for several generations

18. III. RNA Characteristics A. RNA Nucleotide

19. B. Types of RNA 1. Messenger RNA 2. Transfer RNA 3. Ribosomal RNA C. Transcription

20. D. RNA Processing in Eukaryotes

21. E. The Genetic Code: mRNA codons

22. IV. Translation of the Genetic Code A. Protein Synthesis

30. Polysomes

31. V. Mutations to the DNA Molecule

32. Missense

33. Nonsense

34. Frameshift Mutation

35. VI. The Operon Model of Gene Expression A. The Lac Operon