1. MODERN GENETICS DNA

2. DNA
Deoxyribonucleic acid is the genetic material that is passed from one generation to the next
The genetic instructions (genes) that are passed on are in the form of a chemical code contained in the DNA of all organisms

3. DNA
DNA controls cellular activity by influencing the production of proteins
Review: What is a protein?
Long chains of amino acids

4. The sequence of amino acids in a protein determines the shape of the molecule
The shape of a protein enables it to carry out specific functions for the cell
(Think enzymes and lock and key!)

5. Proteins
Proteins make up many structures and chemicals in living things:
Enzymes
Cell membrane
Antibodies

6. Hormones
Pigments that make eye and skin color
ETC ETC ETC

7. DNA STRUCTURE
DNA is a very large molecule (polymer) that is made up of smaller units called nucleotides

8. Each nucleotide consists of:
A phosphate
group

9. Deoxyribose which
is a 5 carbon sugar

10. Nitrogen bases , which are
Adenine
Thymine
Guanine
Cytosine

11. A Nucleotide

12. Watson and Crick model of DNA
DNA is organized like a ladder
The sides of the ladder are composed of alternating phosphate and sugar
The rungs of the ladder are composed of nitrogen bases that are held together by weak hydrogen bonds
The ladder is twisted to form a double helix

13. Base pairing
Nitrogen bases combine in a certain order

14. Adenine only pairs with ThymineAT or TA

15. Guanine only pairs with Cytosine
CG or GC

16. DNA Replication DNA makes exact copies of itself
DNA unzips along the weak hydrogen bonds between each base pair
Free nucleotides in the cytoplasm join with the proper base and 2 identical DNA molecules form
This occurs during mitosis and meiosis

18. http://www. lewport. wnyric
DNA Replication - long.htm