1. DNA Replication

2. The structure of DNA consists of two polynucleotide strands wrapped around each other in a double helix Figure 10.3C Twist 1 chocolate coat, Blind (PRA)

3. Hydrogen bonds between bases hold the strands together –Each base pairs with a complementary partner –A pairs with T –G pairs with C

4. Three representations of DNA Figure 10.3D Ribbon modelPartial chemical structureComputer model Hydrogen bond

5. In DNA replication, the strands separate – Enzymes assemble the new strands – With each strand serving as a template DNA REPLICATION 10.4 DNA replication depends on specific base pairing Parental molecule of DNA Figure 10.4A Both parental strands serve as templates Two identical daughter molecules of DNA Nucleotides A A

6. Untwisting and replication of DNA Figure 10.4B

7. DNA replication begins at specific sites 10.5 DNA replication: A closer look Figure 10.5A Parental strand Origin of replication Bubble Two daughter DNA molecules Daughter strand

8. Each strand of the double helix is oriented in the opposite direction Figure 10.5B 5 end3 end 5 end P P P P P P P P

9. How DNA daughter strands are synthesized 5 end P P Parental DNA Figure 10.5C DNA polymerase molecule 5 3 3 5 3 5 Daughter strand synthesized continuously Daughter strand synthesized in pieces DNA ligase Overall direction of replication 5 3 The daughter strands are identical to the parent molecule