DNA structure and function

• DNA


  Deoxyribonucleic acid, codes for amino acid sequences which are the primary structure in proteins
• Every single cell has its own copy of DNA except for red blood cells
• DNA nucleotide


  Contains a phosphate group, a pentose sugar (deoxyribose), and a nitrogen containing base (guanine, cytosine, adenine, thymine)
• DNA polymer formation


  Condensation reaction between phosphate group and deoxyribose forms phosphodiester bond
• Polynucleotide


  The polymer formed from DNA nucleotides
• Sugar phosphate backbone


  The strong covalent bonds holding the DNA nucleotides together
• DNA structure


  • Double stranded, forms a double helix
• Complementary base pairing


  Cytosine-guanine, adenine-thymine, held together by hydrogen bonds
• Complementary base pairing


  Ensures identical copies are created during DNA replication
• DNA


  • Stable structure due to strong covalent bonds in sugar phosphate backbone
  • Can be tightly coiled and condensed to fit large amounts of genetic information in a small space
  • Weak hydrogen bonds between bases allow for easy separation during replication
• DNA is one of the biological polymers