Nucleic Acids

Principles Module 12


  • Describe the general structure of nucleic acids
  • Discuss how nucleic acids encode information

Key points

  • nucleic acid polymers are not repeats of the identical monomer
  • nucleotides are made up of a sugar, a nitrogenous base, and a phosphate
    • five kinds based on differing N-base
    • purines (A, G) and pyrimidines (C, T, U)
  • phosphodiester bond formation is energy-releasing
  • DNA secondary structure forms double-helix
    • antiparallel strands
    • bases toward inside, pair by H-bonding
  • each strand acts as a template for new strand by base-pairing
  • sequences of DNA encode genes, which specify proteins

In-class activities