Nucleotide Structure: Pentose sugar
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Transcript of Nucleotide Structure: Pentose sugar
Nucleotide Structure: Pentose sugar
Nucleotide Structure: Nitrogenous Bases
DNA Linkage
• Phosphate group/phosphodiester bond• Nucleotides contain one, two, or three
phosphate groups
*nucleoside *nucleotide
Nucleic Acid Polarity
*Top of molecule hasfree 5’-phosphate
group
This is the 5’ end
*Bottom has a free 3’hydroxyl group
This is the 3’ end
*Early 1950’s Rosalind Franklin
*1953 Watson and Crick
Structural analysis of DNA
Complementarity
DNA Structure:
Brief Review of DNA Replication:
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
A
C
G
T
T
C
ssDNA:
*
ssDNA treated with micrococcal nuclease:
A
C
G
T
T
C
*
Exercise:
List all possible dinucleotides (analysis of nearest 5’ neighbor)
Which must be present in equal frequencies if the DNA strands are:
Parallel ? Antiparallel?