DNA replication

Question 1

1)

Answer 1

• enzyme DNA helicase breaks the hydrogen bonds between bases on the two polynucleotide DNA strands.
• helix unwinds to form two single strands.

Question 2

2)

Answer 2

• Each orginal single strand acts as a template for new strand.
• complementary base pairing = free-floating DNA nucleotides are attracted to complementary exposed bases on each original template strand.

Question 3

3)

Answer 3

• Condensation reactions joing nucleotides of the new strands together (forming phosphodiester bond between phosphate + hydroxyl groups) - catalysed by the enzyme DNA polymerase.
• Hydrogen bonds form between bases on the orginal and new strands.

Question 4

4)

Answer 4

• each new DNA molecule contains one strand from the orginal and one new strand.