1. DISCOVERY OF THE STRUCTURE OF DNA Hank Oliver and Chelsea Peacock

2. Frederick Griffith  Discovered the process called transformation  Found a transforming agent that survived heat and change a bacteria to virulent

3. Oswald Avery and Colleagues  Proved DNA was the transforming compound  Used protein-destroying enzymes to destroy proteins, RNA-destroying enzymes to destroy RNA, and DNA- destroying enzymes to destroy DNA.  Transformation was stopped when DNA-destroying enzymes were used.

4. Alfred Hershey & Martha Chase  Performed experiment with T2 bacteriophage  Using radiolabeled proteins and DNA and followed them.  Experiment proved DNA was transforming agent

5. Rosalind Franklin & Raymond Gosling  Worked together to produce the first X-ray diffraction pictures of DNA  Their picture of DNA was stolen by Watson & Crick to determine the structure of DNA

6. Erwin Chargaff  The amount of cytosine equals the amount of guanine and the amount of adenine equals the amount of thymine.  Adenine ALWAYS pairs with Thymine; Guanine ALWAYS pairs with Cytosine – Chargaff’s Rule

7. Maurice Wilkins  Studied the orientation of purines and pyrimidines in DNA  Developed well-defined X-ray diffraction pictures of DNA which led to Watson and Crick’s DNA model

8. James Watson & Francis Crick  First to determine structure of DNA  Double helix  Chargaff’s Rule  Made of sugar-phosphate backbone with bases hydrogen bonded together holding two strands together

9. References Griffith Experiment http://www.nature.com/scitable/topicpage/isolating-hereditary-material-frederick-griffith-oswald-avery-336 Avery Experiment http://study-biology.wikispaces.com/DNA+and+Genetic+Information Hershey & Chase Experiment http://www.accessexcellence.org/RC/VL/GG/hershey.php Rosalind Franklin’s X-ray Picture http://biology.kenyon.edu/courses/biol63/dna-prot/xray.html Rosalind Franklin Picture http://askabiologist.asu.edu/Rosalind_Franklin-DNA Raymond Gosling Picture http://kingscollections.org/exhibitions/archives/dna/key-individuals/gosling Image for Chargaff’s Rule http://www.odec.ca/projects/2004/mcgo4s0/public_html/t2/dna.html Chargaff Picture http://sanycao-sbi4u.blogspot.com/2012/02/scientists-great-contributions.html

10. References Maurice Wilkins Picture http://scarc.library.oregonstate.edu/coll/pauling/dna/pictures/portrait-wilkinsmodel.html Watson and Crick Picture http://www.chemheritage.org/discover/online-resources/chemistry-in-history/themes/biomolecules/dna/watson-crick- wilkins-franklin.aspx DNA Structure http://library.thinkquest.org/24355/data/details/media/dnastructure.html