1. IB Topics3.4 & 7.2- DNA Replication
Focus Question:
How does DNA replicate?
IB Topics:
3.4 DNA Replication
7.2 DNA Replication

2. DNA Replication

4. Direction of DNA Replication
DNA replication occurs in a 5’ to 3’ direction!

5. Enzymes drive replication
Helicase
DNA polymerase III,
RNA primase
DNA polymerase I
DNA ligase

6. Okazaki fragments
In eukaryotes, replication is initiated at many points concurrently.

7. DNA Replication
Semi-conservative-

8. Excision Repair

9. Replication Enzymes
Which enzymes are important for DNA replication?

10. Helicase 1) unwinds the double helix
2) breaks apart the H-bonds between base pairs

11. RNA Primase
Assembles and positions RNA primer

12. Deoxynucleoside triphosphate
not an enzyme, but an important molecule
Contains the base, sugar and three phosphates
The precursor to a nucleotide.

13. DNA Polymerase III
Facilitates the joining of deoxynucleoside triphosphate to the template strand.
Condensation reaction, two phosphates are removed, rest stays on strand.
Water forms
Adds nucleotides in the 5’ to 3’ direction

14. DNA Polymerase I
Removes RNA primer and replaces with DNA

15. DNA Ligase
Attaches DNA segments of Okasaki fragments.

17. DNA Replication Initiated at many points
Animation