1. DNA, RNA & Protein Synthesis

2. How long do you think we’ve known about DNA?
Johannes Friedrich Miescher (swiss biologist and physician) – published a study in 1871 detailing the discovery of a new organic compound found in the nucleus of white blood cells

3. Experiments Frederick Griffith
Conclusion: There are hereditary factors
that can transfer traits from
one organism to another.
(TRANSFORMATION)

4. Experiments

5. Experiments Oswald Avery Conclusion: DNA (not protein) is
responsible for transforming the
bacteria in Griffith’s experiment

6. Experiments

7. Experiments Martha Chase & Alfred Hershey
Conclusion: DNA (not protein)
is the hereditary material in viruses

8. Experiments
Martha Chase & Alfred Hershey

9. Experiments Erwin Chargaff
Analyzed the amount of each molecule present
in DNA molecules taken from various species

10. Experiments Concluded: that DNA is composed of equal parts
Erwin Chargaff
Analyzed the amount of each molecule present
in DNA molecules
Concluded: that DNA is composed of equal parts
Adenine and Thymine and equal parts
Cytosine and Guanine. We call it “base pairing”.

11. Experiments Rosalind Franklin X-ray crystallography of DNA
molecule reviled the size
(width) of the molecule and ladder and the twisted nature of the molecule.

12. Experiments
Rosalind Franklin

13. The Structure of DNA
Putting it all together: James Watson & Francis Crick

14. The Structure of DNA Rungs of the ladder – Purine and Pyrimdine Bases
Basic Structure – A twisted ladder
Sides of the ladder – Sugar and Phosphate groups
Rungs of the ladder – Purine and Pyrimdine Bases
Base Pairing – Adenine with Thymine & Guanine with Cytosine

15. The Structure of DNA

16. The Structure of DNA
Nitrogenous Bases

17. The Structure of DNA
Nucleotide

19. The Structure of DNA
C with G T with A

20. What is different about AT bonds and GC bonds?

21. The Structure of DNA
How many nucleotides are here?