01 DNA

Structure

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• ribose backbone connected by phosphate group

• 5' phosphate and 3' OH

• during addition, 2 phosphate groups cut off. Monophosphate added to growing strains

Replication

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• origin of replication

• DNA helicase: separates and unwinds, require ATP

• 2 bonds at AT

• major enzyme that makes new DNA

Primers

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• DNA polymerase requires primers

• RNA polymerase does not require primer

Directionality

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• DNA polymerase break phosphate bond between 1 and 2 phosphate, creating energy needed to add nucleotide to DNA strand

• phosphate bond on nucleotide can only go at 3' end where OH is

• primer added to 3' end

• nucleotides added to 3' end of primer in 5 to 3 direction

• bottom strand in pieces

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Proofreading

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• DNA polymerase can move backwards using exonuclease activity

Telomerase

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• takes a piece of RNA and makes DNA that replaces telomere

• TTAGG near 3'