The Molecular Basis of Genetics Chapter 10: DNA Structure and Analysis

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The Molecular Basis of Genetics
Chapter 10 DNA Structure and Analysis
The flow of information
1. Storage
3. Expression
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DNA as the Genetic Material
Historically
1868 Friedrick Miescher
1910 Phoebus Levene tetranucleotide hypothesis
1927 Frederick Griffith transforming principle
1944 Avery, MacLeod and McCarty
1952 Alfred Hershey and Martha Chase
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Evidence for DNA in Eukaryotes
Indirect evidence Distribution of
DNA Mutagenesis
Direct evidence Recombinant DNA technology
Organism n 2n
Human 3.25 7.30
Chicken 1.26 2.49
Trout 2.67 5.79
RNA genetic material in some viruses
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Structural Analysis of DNA
nucleoside nucleotide
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Base Composition
1949-1953 Chargaffs Rules

Source A T G C A/T G/C AG/CT AT/CG
Human 30.9 29.4 19.9 19.8 1.05 1.00 1.04 1.52
Sea Urchin 32.8 32.1 17.7 17.3 1.02 1.02 1.02 1.58
E. coli 24.7 23.6 26.0 25.7 1.04 1.01 1.03 0.93
T7 26.0 26.0 24.0 24.0 1.00 1.00 1.00 1.08


Organism GC
Phage T2 36.0
Drosophila 45.0
Maize 49.1
Euglena 53.5
Neurospora 53.7
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DNA Structure
1953 Watson and Crick
Early 1950s Rosalind Franklin
Linus Pauling
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RNA Structure
Similar to DNA except
Three major classes of RNA
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Analysis of Nucleic Acids
Molecular Hybridization Reassociation
Kinetics Electrophoresis