1. DNA (Deoxyribonucleic Acid)
History and Structure
C10L28C12

2. Chromosomes are made of DNA
Chromosomes and DNA
During Mitosis we can
see Chromosomes
Chromosomes are made of DNA

3. Chromosomes and DNA

4. Today’s Goals Item 1 What is DNA? Item 2 DNA History Item 3
DNA Structure
Item 4
DNA Nitrogen Bases
Item 5
Chargaff's Rule

5. What is DNA?
DNA holds all the genetic information that determines an organism’s traits.
Height
Hair Color
Skin Tone
Eye Color

6. What is DNA?
Within the structure of DNA is the information for life—the complete instructions for manufacturing all the proteins for an organism.
DNA achieves its control by determining the structure of proteins.
Enzymes (a type of protein) control the chemical reactions needed for life.
Eating, running, even thinking

7. Today’s Goals Item 1 What is DNA? Item 2 DNA History Item 3
DNA Structure
Item 4
DNA Nitrogen Bases
Item 5
Chargaff's Rule

8. Rosalind Franklin 1952 Twisted strands (helix)
Studied DNA structure with X-ray diffraction
Important clues to the structure of DNA
Twisted strands (helix)
Angle suggested 2 strands ( double-helix)
Nitrogen bases near the center of the molecule

9. James Watson and Francis Crick
1953
Built a DNA model based on the clues from Franklins X-ray diffraction

10. Today’s Goals Item 1 What is DNA? Item 2 DNA History Item 3
DNA Structure
Item 4
DNA Nitrogen Bases
Item 5
Chargaff's Rule

11. DNA is a Double Helix
A double helix looks like a twisted ladder.

12. The Double Helix Building Blocks
A DNA strand is a polymer.
They are very long!
It’s length is what allows DNA
to hold so much information
The repeating subunits
of DNA are called
nucleotides

13. Nucleotide Structure Composed of 3 parts Phosphate Nitrogen Base
There are 4
possible bases.
Broken down into
2 categories
Phosphate
Nitrogen
Base
Deoxyribose
Sugar

14. Nucleotide Structure
The phosphate groups and deoxyribose (sugar) molecules bond to form the backbone of the chain
The nitrogenous bases stick out like the teeth of a zipper.

15. Today’s Goals Item 1 What is DNA? Item 2 DNA History Item 3
DNA Structure
Item 4
DNA Nitrogen Bases
Item 5
Chargaff's Rule

16. Types of Nitrogen bases
There are two types of nitrogen bases
Purines
Pyrimidines
Pyrimadines have one ring
Purines have two rings

17. Types of Nitrogen bases
There are two types of nitrogen bases
Purines
Pyrimidines

18. Today’s Goals Item 1 What is DNA? Item 2 DNA History Item 3
DNA Structure
Item 4
DNA Nitrogen Bases
Item 5
Chargaff's Rule

19. How the double helix is formed
Nitrogen bases bond to one another to connect the two strands
But only certain bases can bond to one another

20. Chargaff’s Rule – Base Pairing
1 Purine must bond to 1 pyrimadine
Adenine only bonds to Thymine
Guanine only bonds to Cytosine
The At
Grand
Canyon

21. OVERVIEW