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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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