1. An Overview of the Process
DNA Replication
An Overview of the Process

2. Replication Defined… DNA Replication
Prior to dividing, a cell will replicate (or make a copy of) its DNA in the nucleus to ensure that each new daughter cell has a complete set of DNA molecules

3. When is DNA Replicated? Remember:
The cell cycle consists of a series of steps:
Interphase
G1: cell growth
S: Chromosome replication/DNA synthesis
G2: organelles essential to division are made
M Phase
Mitosis
Prophase
Metaphase
Anaphase
Telophase
Cell Division
Cytokinesis

4. How is DNA Replicated? The long version:
This is when the double helix is separated into 2 separate “template” strands by an enzyme called helicase, so that an enzyme called DNA polymerase can pair free floating bases to the “template” strand forming a new “complimentary” strand, thus duplicating the existing supply of DNA molecules…
…whoa…let’s break it down.

5. How is DNA Separated?
The 2 sides of the DNA molecule are separated into 2 separate “strands” by an enzyme called helicase

6. Key Info: An enzyme called helicase?
Back up: an enzyme is a protein that acts as a biological catalyst
Back up further: a catalyst is a substance that speeds up the rate of a chemical reaction
Put it together: helicase is a substance made of protein that helps the process of DNA replication

7. How is DNA Separated?
As you can see, helicase “unzips” or “unwinds” the double helix of DNA into 2 separate strands by breaking hydrogen bonds between bases
You are left with 2 template strands
A template strand is a strand of DNA that you can use to build another matching strand, thus making more DNA
replication bubble

8. How is New DNA Made?
With the 2 template strands separated, we can see how new DNA is made:
Another enzyme called DNA Polymerase attaches free floating bases to the template strands following the rules of base pairing
(A with T, G with C)
Take a look…

9. How is New DNA Made?

10. Better Yet…