1. Ch. 11.2 & 11.3 Notes DNA & DNA Replication

2. What do we already know about DNA?
Why do we care about DNA?

3. DNA
What does it stand for?
Why is it so important for your body?
What does it look like?
Deoxyribonucleic acid
It controls all your body functions and what you look like
Double helix – spiral staircase

4. Nucleotide
What is it?
It is made up of three parts: 1. 2. 3.
Picture:
The building blocks of DNA (what it is made of)
Phosphate
Sugar - Deoxyribose
Nitrogenous Base

5. Nitrogenous Base
There are four different bases:
Which bases are purines?
Which bases are pyrimidines?
Base Pairs:
____________ always pairs with ____________
Thymine (T)
Adenine (A)
Cytosine (C)
Guanine (G)
A & G
C & T

6. Base Pairs

7.  Circle ONE nucleotide
What does DNA look like?
This shape is called a
 Circle ONE nucleotide
When DNA is straightened out it looks like:
-Circle one nucleotide
-Point to one backbone
-Point to the base pairs
What two things make up
the DNA backbone?
double helix
sugar & phosphate

8. DNA
Replication
What happens?
The Steps of DNA Replication 1. 2. 3.
DNA Polymerase
The copying of the DNA
DNA unzips
Free floating nucleotides pair up with open DNA ends
Two new DNA strands made.
It seals the new backbone of DNA together

9. What DNA Replication looks like
Original DNA strand:
Step 1 – The DNA ___________________.
Step 2 – The bases _____________________________________.
Step 3 – The back of the new DNA ________________________
unzips
get a new partner (new base)
binds together with DNA polymerase.

10. When does DNA replication happen?
When is DNA replication done?
Why is DNA replication so important?
Right before the start of cell division (when your body needs to make new cells…for example to heal a cut)
When you have 2 exact copies of the original DNA strand. Each new strand will be half new, half old DNA.
All new cells have the same DNA as the original cell

11. Each new DNA is half original and half new

12. DNA Replication animation
The DNA staircase
DNA Replication animation
More complex animation: (show if you want)