DNA replication

• why does DNA replicate?

  so that the cell has the full amount of DNA before cell division
• what is the method called through which DNA divides?

  semi-conservative replication
• why is it called semi-conservative replication?

  because half the strands in each new DNA molecule are from the original DNA molecule
• What enzyme breaks the hydrogen bonds during DNA replication?

  DNA helicase
• What happens to the DNA helix during replication?

  It unwinds to form two single strands
• How do the single strands of DNA function during replication?

  They act as templates for new strands
• What is the role of complementary base pairing in DNA replication?

  It attracts free nucleotides to the template strand
• What type of reaction joins nucleotides in the new DNA strand?

  Condensation reactions
• Which enzyme catalyzes the joining of nucleotides in DNA replication?

  DNA polymerase
• What forms between the bases on the original and new DNA strands?

  Hydrogen bonds
• What is the composition of each new DNA molecule after replication?

  One old strand and one new strand
• how is each end of a DNA strand different?

  one end is 3' and the other is 5'
• which side is only complementary to 3'?

  polymerase - so the enzyme can only add nucleotides to the new strand at the 3' side. this means that the new strand is made in a 5' to 3' direction and that DNA polymerase moves down the template strand in a 3' to 5' direction