Nucleic acids

• DNA


  • Two strands
  • Deoxyribose sugar
  • Longer
  • ATCG
  • Double helix (crick and watson)
  • Antiparallel
  • 5' has the phosphate on top
• RNA


  • Ribose sugar - has one less oxygen
  • One strand
  • Shorter
  • AUCG
• Purine


  • 2 rings
  • AD
• Pyrimidines


  • 1 ring
  • CTU
• Chargaff


  Discovered complementary base pairing through induction
• Tetranucleotide hypothesis


  • Old
  • DNA was made of repeating units of ATGC
  • Disproved by Chargaff
• Nucleosomes


  • Help to supercoil and package the DNA into a smaller volume
  • Naked DNA wraps around histones
  • Efficient storage, protects DNA, control gene expression
  • DNA wrapped around eight histones