DISCOVERY OF THE STRUCTURE OF DNA Hank Oliver and Chelsea Peacock

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

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.

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

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

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

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

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

References Griffith Experiment Avery Experiment Hershey & Chase Experiment Rosalind Franklin’s X-ray Picture Rosalind Franklin Picture Raymond Gosling Picture Image for Chargaff’s Rule Chargaff Picture

References Maurice Wilkins Picture Watson and Crick Picture wilkins-franklin.aspx DNA Structure