DNA and Chromosome Structure DNA and Chromosome Structure

DNA and Chromosome Structure

DNA and Chromosome Structure A. The Structure of DNA

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

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

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

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

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)

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 OH O-P-O O H 2 O OH

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’

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… 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 4. DNA is a double helix – two nucleic acid strands arranged in a complementary, anti-parallel orientation… ANTI-PARALLEL… 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…

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

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

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

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

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…

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

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