a b and z dna
TRANSCRIPT
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DNA“THE BLUEPRINT OF LIFE”
SUJITA MISHRAPI/289
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Contents
History of DNA
Genetic material of cells
DNA double helix
DNA replication
ABZs of DNA
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DNA
(Deoxyribonucleic Acid)
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A History Of DNA
R.FRANKLIN X-ray photo of DNA. (1952)
Watson & CrickDescribed the DNA from Franklin’s x-ray.
(1953)
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GENESUnits of genetic material that codes for a specific
trait.
DNA is made up of repeating molecules called as Nucleotides.
Genetic Material Of Cells
What IS A NUCLEOTIDE ?
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DNA Nucleotide
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DNA Double Helix
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Nitrogenous Base
PURINES• Adenine(A)• Guanine(G)
PYRIMIDINES• Thymine(T)• Cytosine(C)
A or G
T or C
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DNA Replication
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THE ABZs OF DNA
Major forms Of DNA
A-DNA Right handed,short & broad,11bp per turn.
B-DNA Right handed,longer,thinner,10 bp per turn.
Z-DNA Left handed,longest,thinnest,12 bp per turn.
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THE ABZs OF DNA
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Observed in active site of DNA polymerase
Gram+ bacteria undergoing sporulation.
Deep major groove & shallow minor groove.
Observed under dehydrating conditions. B-DNAA-DNA (Reversible).
A-DNA
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Most common DNA.
Each base pair has same width.
Minor groove is narrow & major groove is wide.
B-DNA
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Seen in conditions of high salt concentration.
Deep minor groove.
No discernible major groove.
Z-DNA
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