1. DNA History,Structure,and

2. Check out Griffith’s experiment on page 138
What is up?
Shows how harmless bacteria can turn deadly.
How? DNA is transferred!

3. DNA (de-oxy-ribo-nucleic acid) a nucleic acid that stores and transmits the genetic information from one generation to the next

4. Big Players in DNA
Chargaff
Rosalind Franklin
Watson and Crick

5. People knew that DNA was made up of:
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)

6. Erwin Chargaff
Discovered that in any sample of DNA, the amount of A equals the amount of T and the amount of C equals the amount of G.
This suggested that A binds with T and that C binds with G.

7. Rosalind Franklin’s X-Ray Crystallography
Took x-ray photographs of crystallized DNA
Discovered that the shape of DNA must be a helix, because of the x-ray pattern
Died of cancer
(too many x-rays?)

8. An example of X-Ray Crystallography

9. Watson and Crick Credited for discovering the structure of DNA in 1953
Used Chargaff and Franklin’s discoveries along with toy models to discover the structure

10. A 3-D Model of DNA

13. NUCLEOTIDES Made up of: A phosphate group 5 carbon sugar
Nitrogenous Base
(nitrogen containing)

14. PURINES
Adenine (A)
Guanine (G)

15. PYRIMIDINES
Cytosine (C)
Thymine (T)

16. Base Pairing in DNA
A-T
C-G

19. Guanine Nucleotide

20. Write the complementary DNA strand for each of these DNA strands:
GAATTACA
CCAATTAG
ATAGACAG
CCAGTACA
DNA
CTTAATGT
GGTTAATC
TATCTGTC
GGTCATGT

21. Examples of DNA Replication