Discovery of the Double Helix - rio.edu Franklin (1920 - 1958) •England •PhD Physical Chemistry...
Transcript of Discovery of the Double Helix - rio.edu Franklin (1920 - 1958) •England •PhD Physical Chemistry...
1944 Avery, MacLeod & McCarty
Centrifuge Heat Blender
proteaseremoves protein
RNAaseremoves RNA
DNAaseremoves DNA
R R R
S
DNA transformsR to S form
1952 Hershey & Chase
DNA not proteinenters bacteria
phageradioactive DNA (P)
phageradioactive DNA
phageradioactive protein (S)
James Watson (1928 -)
•USA•PhD Zoology Indiana•Copenhagen•Post-Doc phages•Naples Conference - DNA•Cambridge University•Cavindish Lab•Human Genome Project
Francis Crick (1916 - 2004)
•England•Physics•War - Mines•Cambridge University•Cavindish Lab•working on PhD
Maurice Wilkins (1916-2004 )
•England•Physics•Manhattan Project•King’s College, London•DNA structure•Naples Conference
Rosalind Franklin (1920 - 1958)•England•PhD Physical Chemistry•France-coal•X-ray diffraction•Kings College •DNA - A and B form•Birkbeck College•Tobacco Mosaic Virus•Aaron Klug
DNA Model
• Based on all above, Watson and Crick developed double helix model of DNA
• 2 strands running anti-parallel• G pairing with C• A pairing with T
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DNA Structure
Sugar
GP O1’
5’
Sugar
AP O1’
5’
Sugar
TP O1’
5’
Sugar
C PO
1’5’
Sugar
T PO
1’5’
Sugar
A PO
1’5’
antiparrallel strands
5’
3’
3’
5’
hydrogenbonding