1. DNA

2. RECALL … 4 classes of macromolecules –Carbohydrates –Lipids –Proteins –NUCLEIC ACIDS!!! –Subunit (Building Blocks): NUCLEOTIDES

3. DNA – deoxyriboNUCLEIC ACID (de – without, oxy – oxygen, ribo – ribose sugar) Store and pass genetic information Building Block of DNA: nucleotides

4. DNA Very longVery long thin molecule made up of linked nucleotides Double stranded helix –Twisted ladder Determines traits of EVERY LIVING ORGANISM

5. Nucleotide Structure 3 parts –Sugar (deoxyribose or ribose) –Phosphate (P with oxygens attached) –Nitrogen base Adenine Thymine Guanine Cytosine

6. Nitrogen Base Pairing Adenine Thymine Guanine Cytosine All Tigers Can Growl

7. Nitrogen Base Pairing Adenine Thymine Guanine Cytosine = Hydrogen Bond

8. Nitrogen Base Pairing Adenine Thymine CytosineGuanine ThymineAdenine CytosineGuanine AdenineThymine Guanine Cytosine = Hydrogen Bond

9. Nitrogen Base Pairing Adenine Thymine CytosineGuanine ThymineAdenine CytosineGuanine AdenineThymine Guanine Cytosine

11. What is the COMPLEMENTARY DNA STRAND? EXAMPLE 1 ATTGACCATTGATAGCCGAATA TAACTGGTAACTATCGGCTTAT EXAMPLE 2 TCTTCGGAACATTAGTCGAGGC AGAAGCCTTGTAATCAGCTCCG

12. CHROMATID DNA ladder DNA double helix Chromatin Coiled up Chromatin 2 Chromatids

13. CHROMOSOME Chromatin 2 Chromatids 2 Chromatids = 1 Chromosome

14. Centromere Holds sister chromatids together in a chromosome

15. Chargraff’s Rule There will be the same number of bases as its complementary base in a DNA molecule. –EX: If there are 80 Adenines then there will be 80 Thymines. – If there is 20% A’s, then how many G’s will there be in a DNA molecule? 30% G’s Why? –Because if there are 20% A’s, then there must be 20% T’s = 40%. –100% - 40%= 60% left for C’s and G’s. –So, 30% for C’s and 30% for G’s.