AP BIOLOGY DNA History & Structure
Nucleic Acid Structure
Complimentary Base Pairing
Frederick Griffith
FREDERICK GRIFFITH EXPERIMENT Living S cells (control) Living R cells (control) Heat-killed S cells (control) Mixture of heat-killed S cells and living R cells Mouse dies Living S cells are found in blood sample Mouse healthy Mouse dies RESULTS
Oswald Avery
Avery and group identified the transforming substance was DNA. His colleagues were McCarty and MacLeod.
Alfred Hershey & Martha Chase
Bacteriophage injecting its DNA into a bacterial cell
Electron Microscope View
Hershey – Chase Experiment
Erwin Chargaff
CHARGAFF’S RULE Adenine = Thymine (DNA) or Uracil (RNA) & Guanine = Cytosine If you know the % composition of 1, you can find the % composition of the other 3.
Rosalind Franklin
DNA from a top view
DNA from a side view
James Watson & Francis Crick with their DNA model
See the HYDROGEN bonds?