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

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

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