1. DNA Replication

2. DNA Replication
DNA must be replicated (copied) so cells can undergo growth and division
Occurs in the nucleus
Occurs during Interphase (S phase)* of the cell cycle

3. DNA Replication Step 1: “Unzip”
The enzyme Helicase separates the 2 DNA strands
Breaks the weak hydrogen bonds
Occurs at the replication fork

4. DNA Replication Step 2: “Create”
The enzyme DNA Polymerase attaches the complementary nitrogen bases to the “unzipped” DNA strands
(A-T) and (G-C)

5. DNA Replication
Step 3:
Once the nitrogen bases are added, the enzyme Ligase proof reads and “re-zips” the DNA.
Each DNA helix has one new and one old DNA strand → This is called semi-conservative

6. DNA Replication
Product of DNA replication = 2 identical strands of DNA
The cell now has 2 identical copies of it’s DNA and is now ready to undergo cell division!
The new identical strand of DNA is for the new cell!

7. Semi-Conservative Original G--C C--G T--A A--T Daughter 1 G--C C--G

8. DNA Replication
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