Question

Differentiate between the following:

Helicases and DNA ligase

Answer 1

Basis of Difference	Helicases	DNA ligase
Main function	Helicases unwind and separate the two DNA strands.	DNA ligase joins separate sections of newly synthesised DNA.
Action on DNA	Helicases break the hydrogen bonds between complementary bases.	DNA ligase seals breaks in the sugar-phosphate backbone by forming phosphodiester bonds.
Role in replication	Helicases open the DNA double helix at the replication fork.	DNA ligase joins Okazaki fragments on the lagging strand.
Effect	Helicase activity exposes the DNA strands so they can act as templates.	Ligase activity makes a continuous DNA strand from separate DNA fragments.