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Molecular Biology Chapter 10: DNA Replication

Worksheet I. DNA Structure

Things to keep in mind:

• how DNA, chromatin and chromosomes all fit together

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Things to keep in mind about DNA pairing:

• base pairs • 3’ and 5’ ends

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• Each strand of the double helix is oriented in the opposite direction

Figure 10.5B

5′ end 3′ end

3′ end 5′ end

P

P

P

P

P

P

P

P

3’ END: 5’ END:

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Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Three representations of DNA

Figure 10.3D

Ribbon model Partial chemical structure Computer model

Hydrogen bond

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II. DNA REPLICATION Overview of DNA Replication – both parental strands serve as template strands:

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Untwisting and replication of DNA

Figure 10.4B

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ORIGIN OF REPLICATION:

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• DNA replication begins at specific sites

10.5 DNA replication: A closer look

Figure 10.5A

Parental strandOrigin of replication

Bubble

Two daughter DNA molecules

Daughter strand

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PRIMING DNA

• know which end nucleotides are added to

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LEADING AND LAGGING STRANDS:

• know which strand is leading and which is lagging • know how the following enzymes are involved:

- helicase - single stranded binding proteins - RNA primase - DNA polymerase - DNA ligase

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REVIEW: