1. DNA Replication pp

2. Location Occurs wherever the DNA is located
Where is the DNA located in eukaryotes?
Where is the DNA located in prokaryotes?

3. Replication Steps Making copies of DNA
Occurs when a cell divides to make new cells
The two strands separate and unwind acting as a template to add new nucleotides

5. First Step Origin of replication: where replication will start
DNA is split by helicase by breaking the hydrogen bonds
replication fork: point where helicase separates DNA

6. Second Step
DNA polymerase adds nucleotides from surrounding open areas ( A- T, G-C) as it unzips

7. Process continues until entire strand is copied
Result is two strands of DNA
Each strand is 50% new and 50% old DNA (semi-conservative)

8. Cell Cycle

9. G1 phase: cell grow to normal size
S phase: copying of DNA (replication)
G2 phase: cell preps for division
M phase (mitosis): division of the nucleus

10. Accuracy and Repair Copies must be 100% accurate
Mutation= change in nucleotide
Enzymes proofread and fix errors

11. Q: What happens if mistakes are made during replication?