1. DNA Notes

2. What is DNA DNA stands for Deoxyribonucleic Acid
DNA – The material inside the nucleus of cells that carries genetic information.

3. Discovering the Structure of DNA
Structure was discovered in 1953 by James Watson and Francis Crick

4. Function of DNA
Stores genetic information that instructs the cell on what proteins to make and where to make them
Responsible for determining all organism’s traits such as eye color, body structure, and cellular enzyme production (exact words from a previous TAKS test).

5. The Components of DNA
DNA is a long molecule made up of repeating individual units called nucleotides.
Nucleotides are made up of three parts:
Sugar
Phosphate Group
Nitrogenous Base

6. Nitrogenous Bases DNA contains four nitrogenous bases: Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)

7. Nucleotides Put Together = DNA
DRAW THIS PART ON YOUR NOTES!

8. Structure of DNA Phosphate Group & Deoxyribose Sugar Nitrogenous Bases
Form the backbone or sides of the ladder.
Nitrogenous Bases
Form the “rungs” of the ladder or middle of the molecule.

9. The Shape of DNA
DNA looks like a “twisted ladder” called a Double Helix.

10. Pictures Of The Double Helix

11. In DNA, Which Bases Pair? Adenine (A) always pairs with Thymine (T)
Spells “AT”
Guanine (G) always pairs with Cytosine (C)
“G” and “C” look very similar
This is the principle of base pairing

12. Complimentary Bases A - T and G - C are complimentary base pairs.
Bases are held together by hydrogen bonds.

13. You Try It!
What is the complimentary DNA strand if the original DNA strand is AGTCTA?

14. You Try It!
What is the complimentary DNA strand if the original DNA strand is AGTCTA?
TCAGAT