1. Chapter 8 From DNA to Protein

2. 8-2 DNA Structure 3 understandingsGenes 1. Carry information for one generation to the next 2. Determine which traits are inherited 3. Easily copied

3. 8-2 DNA Structure Structure of DNA *Made of units called nucleotides Nucleotides have 3 parts 1. 5-carbon sugar (Deoxyribose) 2. Phosphate group 3. Nitrogen base

4. Nucleotide Sugar-phosphate “backbone” Hydrogen bonds

5. 8-2 DNA Structure Nitrogen bases Adenine (A) Guanine (G) Cytosine (C) Thymine (T) A & G - Purines C & T - Pyrimidines --Contains 2 rings --Contains 1 ring

6. Purine Pyrimidines AdenineGuanineCytosineThymine

7. 8-2 DNA Structure DNA Backbone *5-carbon sugar *Phosphate group Chargaff % of C = % of G % of T = % of A *Chargaff’s Rules

8. 8-2 DNA Structure Rosalind Franklin *X-ray of DNA *This led to double helix discovery Double helix *2-strands twisted around each other Example: twisted ladder, spiral staircase

9. 8-2 DNA Structure Watson & Crick *First to model the double helix Base- pairings *Explains Chargaff’s Rules *Guanine is paired with Cytosine *Thymine is paired with Adenine