1. DNA Replication

2. DNA Replication… M S is the process by which DNA is copied
takes place during S phase
is required for the formation of two identical daughter cells in mitosis S M
Enough for one cell
Enough to share

3. DNA Replication… is semi-conservative:
Each half of a DNA “ladder” serves as a template
Each new DNA molecule has one side of original DNA (conserved) and one side that is brand new
Original DNA (conserved)
New DNA
Original DNA

4. DNA Replication… relies on enzymes:
Helicase unzips (splits apart) the two sides of a DNA molecule by breaking hydrogen bonds between base pairs
DNA polymerase adds new nucleotides to the templates following the rules of base pairing
occurs at the replication fork (area of unzipping)

5. Step One The DNA double helix uncurls to form a ladder shape.
At this point, there are two complementary strands
It prepares for replication

6. STEP TWO
The two DNA strands are separated by the breaking of the hydrogen bonds by helicase
This forms a replication “fork”
Add clip of replication fork

7. Step THREE
Polymerase attaches free- floating nucleotides into correct base pairs
Hydrogen bonds re-form

8. Step four Two identical daughter strands are formed!
Base pairs consist of one original strand and its complement