Construct a DNA fragment

  1. We will use a sheet diagramming ten nucleotides :
    1. The nucleotides are differentiated by shading and their purine or pyrimidine shapes.
    2. The sheet contains 3 adenine nucleotides.
    3. You should be able to determine the identities of the other nucleotides (T,C or G) on the sheet.
    4. Label each nucleotide with its letter symbol (A,T,C or G) on the nitrogenous base.
  2. Cut out the nucleotides, be sure not to cut off the line symbolizing the bond to the phosphate group.
  3. You will construct a DNA fragment of 5 base pairs.
  4. On your desk, arrange the left-hand strand nucleotides to read CATTG (from top to bottom).
  5. Create the complementary right-hand strand.
    1. Remember the two strands are anti-parallel.
    2. The sides of a nitrogenous base will touch its complement.
    3. Make sure the phosphate group bond line connects to the next 3' carbon atom.
  6. When you are happy with your DNA, paste the nucleotides to a sheet.
  7. For both strands label the 3' and 5' ends.
  8. Draw an oval around the sugar-phosphate backbones.