1. DNA
Structure

2. What is DNA?
What is DNA for?

4. DNA Deoxy-ribose Nucleic Acid
Structure that has material that determines an organisms traits
Trait: a characteristic that helps determine a unique individual (makes you YOU)
No one’s DNA is the same (kinda like a fingerprint)

5. DNA Makes You YOU!

6. Discovery Discovered by James Watson and Francis Crick
Made of two chains of nucleotides held together by nitrogenous bases

7. Nucleotides
Structure made of three parts
Phosphate
Sugar
Base

8. Nitrogenous Bases Four types of bases in DNA Adenine = A Guanine = G
Cytosine = C
Thymine = T

9. Purines and Pyrimidines
Two Rings
Adenine , Guanine
One Ring
Thymine , Cytosine

10. Bonding Bases bond to other bases in a very specific way
ADENINE will ONLY bond with THYMINE
CYTOSINE will ONLY bond with GUANINE

11. Two Chains
- the two chains of nucleotides are bound together by the bases
- chains bind together upside down!
- two chains are also spirally around each other
- the complete structure of DNA is called DOUBLE HELIX

12. Questions 1) What does DNA stand for?
2) What three parts make up the nucleotide?
3) What are the four types of bases?
4) Which bases are Purines? Pyrimidines
5) How would you describe the Double Helix?
Answer at the back of your notes ( WRITE THE Q’S !!! )