DNA features, function, structure, and comparison with RNA
DNA contains 4 deoxynucleotides
Phosphodiester backbone (2-deoxyribose attached to base) (Polarity)
The double helical structure of DNA is Strands: held
...
DNA features, function, structure, and comparison with RNA
DNA contains 4 deoxynucleotides
Phosphodiester backbone (2-deoxyribose attached to base) (Polarity)
The double helical structure of DNA is Strands: held together by H bonds between AT(2)
and GC (3)
o Antiparallel strands.
o One turn of B-DNA: 10 base pairs
DNA RNA
2’-Deoxyribose Ribose
Thymine Uracil
Double Stranded Single Strand
Stable Susceptible to alkali ->2’,3’ cyclic diesters of
mononucleotide
Guanine = Cytosine
Adenine = Thymine
Guanine ≠ Cytosine
Adenine ≠ Uracil
DNA replication (involved proteins, Okazaki fragment)
Compaction of chromatin
Chromosomal recombination (crossover): requires alignment of homologous
chromosome during meiosis
Chromosomal integration: incorporation of virus DNA into the host
Transposition: jumping DNA transposes themselves in and out of the host genome which
can affect the function of neighboring DNA sequences. Ex) processed gene in Ig & αglobin
Gene conversion: Similar sequences on chromosomes may pair up & eliminate any
mismatched sequences between them -> accidental fixation of variant one (repetitive
DNA families)
Gene rearrangements: Ig
DNA replication. Interaction of the O protein to the origin of replication (ori) unwinds
DNA at an adjacent A+T-rich region. SSBPs maintains allows helicase, primase, and DNA
polymerase, to bind and to initiate DNA synthesis. The replication fork proceeds as DNA
synthesis occurs continuously (long arrow) on the leading strand and discontinuously
(short arrows) on the lagging strand. The nascent DNA is always synthesized in the 5' to
3' direction.
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