PHYSICS 20E Lecture Notes - Lecture 14: Maurice Wilkins, Nuclear Physics, The Double Helix
Document Summary
All life on earth uses dna to store and transmit an organism"s cellular operating instructions . Dna = double-helix polymer formed of a sugar and phosphate backbone + 4 base-pair molecules. Watson and crick showed how dna can store and replicate information. Chromosomes - threadlike structures in nuclei, may play a role in heredity, made of dna. By 1930s most biologists understood that there was a giant hereditary molecule making up chromosomes. They had even isolated the makeup of this dina. The challenge was to determine how its structure accounts for its role in heredity. Rosalind franklin used x-ray diffraction pattern to take pictures of dna. Atoms are too small to be revealed using visible light. X-ray radiation fits the appropriate wavelength to be diffracted by a dna molecule and produce observable results. When light bounces off atoms in lattice that has a grid size comparable to the light wavelength, we see a.
