DNA

• DNA sugar 


  2-deoxyribose
• structure of nucleotides

  • nucleotides are nitrogen-containing organic substances
  • form the basis of the nucleic acids DNA and RNA

  
• bases

  • a molecule of water is lost through a condensation reaction when the phosphate and sugar (C5-OH) bond
  • another molecule of water is lost by condensation when the (C1-OH) on the sugar and a base bond
• cytosine nucleotide

  
• adenine nucleotide

  
• thymine nucleotide

  
• guanine nucleotide

  
• forming DNA

  • nucleotides can polymerise, forming polymers called polynucleotides
  • these form the basis of DNA
  • two nucleotides join together when the OH groups on the sugar in positions C3 and C5 react with the phosphate groups of other nucleotides
  • this is a condensation reaction and forms a phosphodiester
• hydrogen bonding in DNA

  • the bases in the chains are complimentary to each other
  • A is complimentary to T (2 bonds)
  • G is complimentary to C (3 bonds)