DNA

• DNA NUCLEOTIDE MONOMERS?

  phosphate group, 2-deoxyribose sugar, organic base (adenine/ thymine/ guanine/ cytosine)
• POLYMERISATION OF DNA?

  • nucleotides join when OH of phosphate and OH of sugar react on two separate nucleotides
  • water eliminated
  • backbone of phosphate and sugar formed
  • bases attached
  • any order
  • read by DNA sequencing
• DOUBLE HELIX?

  • two strands
  • held together by hydrogen bonds
  • A to T (2 hydrogen bonds)
  • C to G (3 hydrogen bonds)
  • complementary strands
• CELL DIVISION?

  a.k.a replication

  1. Hydrogen bonds break
  2. Covalent bonds unaffected
  3. Helix strands unravel
  4. Nucleotides pair with exposed bases (A to T, C to G)
  5. Bases link by phosphate-sugar bonds
  6. Two double helix molecules produced