DNA replication

• What is the method of DNA replication called?

  Semi-conservative replication.
• Why is DNA replication called semi-conservative?

  Because each new DNA molecule has one original strand and one new strand.
• What is the role of DNA helicase in replication?

  It unwinds the double helix and breaks the hydrogen bonds between the bases.
• What do the original DNA strands act as during replication?

  They act as templates for building new strands.
• How do free nucleotides attach to the original strands?

  Through complementary base pairing (A with T, C with G).
• Which enzyme catalyses the joining of nucleotides during DNA replication?

  DNA polymerase.
• What bonds are formed between the bases of the new DNA strands?

  Hydrogen bonds.
• What does each new DNA molecule contain after replication?

  One original strand and one new strand.
• Why can hydrogen bonds in DNA be easily broken during replication?

  Because they are relatively weak bonds between the bases.
• What does complementary base pairing ensure during DNA replication?

  It ensures that the correct bases pair together for accurate replication.
• What did Watson and Crick discover about DNA that helps explain replication?

  The structure of DNA allows for easy strand separation and accurate complementary base pairing.
• What is the directional structure of DNA strands?

  5' (5 prime) to 3' (3 prime) direction.
• To which end of the template strand is DNA polymerase complementary?

  The 3' (3 prime) end.
• In which direction does DNA polymerase move along the template strand?

  In the 3' to 5' direction.
• Why is one DNA strand built continuously during replication?

  Because DNA polymerase works continuously on the leading strand.
• Why is the other DNA strand built in sections during replication?

  Because DNA polymerase must detach and re-attach as the DNA unwinds on the lagging strand.
• How does DNA polymerase work on antiparallel strands?

  It can only add nucleotides to the 3' end, so it moves in opposite directions on the two strands.