1. DNA Deoxyribonucleic Acid

2. DNA facts DNA is located in the nucleus of the cell
DNA carries all the information that cells need to function
The information is in code and is different in every organism

3. DNA Structure DNA is shaped like a twisted ladder (double helix)
Rungs are made of four kinds of nitrogen bases that form pairs,
adenine, guanine, cytosine, and thymine
Adenine pairs with Thymine A-T
Cytosine pairs with Guanine C-G
Sides are made of a sugar called deoxyribose connected with phosphates
The order of the rungs of the ladder form the “code” of instructions and is different for every person

5. History of DNA Rosalind Franklin
Worked on X-ray diffraction pictures
Photographed DNA in 1950’s - formed a basis for confirming structure of DNA

6. History of DNA Maurice Wilkins
Worked for 10 years on making a model of the DNA molecule
His work with X-ray diffraction was instrumental in inspiring James Watson
Shared Nobel prize with Watson and Crick

7. History of DNA James Watson Francis Crick
Watson and Crick developed a model of the DNA molecule in 1953 –confirmed by Franklin’s picture
Received the Nobel prize in 1962

8. DNA replication (copying)
The rungs of the ladder “unzip” and new nitrogen bases are added to the ladder.

9. Making a DNA model
In this activity you will make a model of a DNA molecule – just like Watson, Crick and Wilkins.
Color T blue, A red, G yellow, C green
Color phosphates orange
Color sugar gray
Cut out and assemble the model

10. Questions to answer Use your text pg135-136
Name the nitrogen bases.
What do the letters C, T, G, A stand for?
Which nitrogen base pairs with Cytosine?
Which nitrogen base pairs with Adenine?
Describe how the DNA molecule replicates (copies itself).
Draw the replication process