DNA Structure

• DNA (deoxyribonucleic acid)

  • contains instructions, written in chemical code for the production of proteins
  • genetic material that passes information onto the next generation for the continuity of life
• DNA Structure

  • nucleotides
  • sugar-phosphate backbone
  • phosphodiester bonds
  • hydrogen bonds
  • complementary bases
  • 5' to 3' direction
• Nucleotides

  • each nucleotide is made of a pentose sugar, phosphate group and nitrogenous base
  • the basic structural unit of DNA
  • each phosphate group is attached to sugar molecules by a phosphodiester bonds
  • complementary base pairs: A-T, C-G
• DNA molecule

  • double helix shape
  • strands are joined by weak hydrogen bonds between complementary base pairs
• DNA Structure Enables its Function

  • comparison: DNA is very similar in different organisms and less similar in different species
  • replication: complementary bases enable DNA molecule to be replicated
  • heritable: genetic material can be passed onto offspring
  • stores a code: the sequence of nucleotides contains a code in segments called genes