Nucleotide Structure: Pentose sugar

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Nucleotide Structure Pentose sugar
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Nucleotide Structure Nitrogenous Bases
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DNA Linkage

• Phosphate group/phosphodiester bond
• Nucleotides contain one, two, or three phosphate
  groups

nucleoside nucleotide
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Nucleic Acid Polarity

• Top of molecule has
• free 5-phosphate group
• This is the 5 end
• Bottom has a free 3
• hydroxyl group
• This is the 3 end

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Structural analysis of DNA
Early 1950s Rosalind Franklin
1953 Watson and Crick
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Complementarity
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DNA Structure
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(No Transcript)
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Brief Review of DNA Replication
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Nearest Neighbor Analysis (Kornberg 1956)
In vitro DNA synthesis Template DNA DNA
polymerase dNTPs
dTTP
dCTP
dGTP
dATP
Allow DNA replication to take place Denature
DNA Treat with micrococcal nuclease- yields
mononucleotides with 3 terminal phosphates
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ssDNA

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Exercise
List all possible dinucleotides (analysis of
nearest 5 neighbor)
Which must be present in equal frequencies if the
DNA strands are Parallel ? Antiparallel?