1. August 7, 2015
Bell Work:
True or False: All living organisms have DNA.
Objective:
The student will be able to…
Explain his or her knowledge of DNA.
Define DNA

2. Today in History
1912 The Progressive Party nominated Theodore Roosevelt for president.
1971 Apollo 15 returned to Earth after a manned mission to the moon.

3. Contact Info

4. What do you know about DNA?

5. DNA
By the 1950s most scientists were convinced that genes were composed of DNA
DNA: Deoxyribonucleic Acid

6. Watson and Crick
James Watson and Francis Crick were researchers at Cambridge University
They were the first to piece together a model of the structure of DNA
The discovery of the structure of DNA was important because it clarified how DNA could serve as the genetic material.

7. Watson and Crick
Watson and Crick determined the DNA was a double helix
Two strands twisted around each other
Similar to a winding staircase

8. DNA Double-Helix

9. DNA Structure Worksheet

10. DNA Structure Each helix is made of linked nucleotides
Each nucleotide is composed of three groups
A phosphate group
A five carbon sugar molecule
A nitrogen containing base

11. DNA Structure The five carbon sugar is known as deoxyribose
The sugar molecule and the phosphate group are the same for each nucleotide in a molecule of DNA
There are four different nitrogen bases
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)

12. DNA Structure
Purines: nitrogen bases made up of two rings of carbon and nitrogen atoms
Adenine
Guanine
Pyrimidines: nitrogen bases made up of a single ring of carbon and nitrogen atoms
Thymine
Cytosine

13. DNA Structure
Base pairing rules: A purine always pairs with a pyrimidine
Adenine pairs with Thymine
Guanine pairs with Cytosine

14. Nucleotide Base Pairing

15. DNA Structure Adenine forms two hydrogen bonds with Thymine
Cytosine forms three hydrogen bonds with Guanine
The hydrogen bonds keep the two strands of DNA together

16. ATACGACCGTTAC TATGCTGGCAATG
DNA Structure
Strictness of base pairing rules results in two strands that form complementary base pairs
The sequence on one strand determines the sequence on the other strand
ATACGACCGTTAC
TATGCTGGCAATG

17. DNA Structure Worksheet

18. Ticket Out Finish each of these sentences: DNA looks like _____.
I've heard of DNA in _______.
The function of DNA is _______.
DNA is used in society for _______.
DNA is made of ________.
I don't think DNA analysis should be used for _______.