1. DNA and Chromosome Structure

2. A. The Structure of DNA

3. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar

4. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base

5. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base

6. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base, phosphate group

7. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base, phosphate group Diphosphates and triphosphates also occur (ATP, GTP)

8. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base, phosphate group 2. Polymerization occurs by dehydration synthesis OH O-P-O O OH H2OH2O

9. DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base, phosphate group 2. Polymerization occurs by dehydration synthesis 3. Polmerization results in a nucleic acid with polarity (not same at both ends) 5’ 3’

10. A purine (A or G) always binds with a pyrimidine (T or C) In fact, A with T (2 h-bonds) And G with C (3 h-bonds) DNA and Chromosome Structure A. The Structure of DNA 1. monomers are “nucleotides” three parts: - pentose sugar, nitrogenous base, phosphate group 2. Polymerization occurs by dehydration synthesis 3. Polmerization results in a nucleic acid with polarity 4. DNA is a double helix – two nucleic acid strands arranged in a complementary, anti-parallel orientation… COMPLEMENTARY…

11. 5’ DNA and Chromosome Structure A. The Structure of DNA 4. DNA is a double helix – two nucleic acid strands arranged in a complementary, anti-parallel orientation… ANTI-PARALLEL…

12. DNA and Chromosome Structure A. The Structure of DNA 4. DNA is a double helix – two nucleic acid strands arranged in a complementary, anti-parallel orientation…

13. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure

14. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure 1. Eukaryotic chromosomes

15. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure 1. Eukaryotic chromosomes DNA wrapped around histone proteins into nucleosomes

16. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure 1. Eukaryotic chromosomes DNA wrapped around histone proteins into nucleosomes 6 nucleosomes per solenoid…

17. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure 1. Eukaryotic chromosomes DNA wrapped around histone proteins into nucleosomes 6 nucleosomes per solenoid… Coiled and supercoiled…

18. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure 1. Eukaryotic chromosomes DNA wrapped around histone proteins into nucleosomes 6 nucleosomes per solenoid… Coiled and supercoiled… Folded to a metaphase chromosome

19. DNA and Chromosome Structure A. DNA Structure B. Chromosome Structure 1. Eukaryotic chromosomes DNA wrapped around histone proteins into nucleosomes 6 nucleosomes per solenoid… Coiled and supercoiled… Folded to a metaphase chromosome