What are the enzymes needed for DNA replication and their roles?

Question

although i probably have the answer in my notes, im confused as to how they work.

Answer 1

The previous poster's link was not available for some reason, so let me see if I can help. There are many different types of enzymes needed for DNA replication and they all have separate functions. However, you must keep in mind that different organisms have different enzymes. Also, the number of enzymes needed for DNA replication varies from species to species.

DNA Polymerase - Elongates a new DNA strand at a replication fork. Adds nucleotides one by one to the new and growing DNA strand.

DNA ligase - Joins sugar-phosphates of Okazaki fragments. Okazaki fragments are found on the lagging strand.

Primase - Starts an RNA chain from scratch that will eventually be replaced by DNA nucleotides (remember nucleotides come from DNA polymerase).

Helicase - Untwists the double helix at replication forks to make two parental strands available as template strands.

Topoisomerase - Relieves strain of ahead of the replication fork due to untwisting of the double helix.

These five enzymes are the most basic needed for DNA replication as has been described above. As I said earlier there are many more enzymes that can be utilized depending on species. Also, if you go more in depth and want to know about proofreading and repairing DNA, even MORE enzymes crop up. I would suggest reading your text book to get a better idea of what is going on. For instance, if we are talking about replication of the lagging strand of DNA, the order of enzymes being put to work would be as follows:

Helicase ---> Topoisomerase ---> Primase ---> DNA polymerase ---> DNA ligase

Hope this helps.

Answer 2

Enzymes In Dna Replication

Answer 3

Dna Replication Enzymes

Answer 4

See the following web site:
http://www.dnareplication.info/enzymesofdnareplication.php. It has the enzymes and their functions.