Question

What is the unit of replication?

Answer 1

Replisome/replicon:

1. Individual units of replication are called replicons, each of which contains a replication origin .
2. Replisome is composed of many proteins, which are required for replication such as DNA polymerase. helicase, primase, ligase, topoisomerase, etc
3. Replication starts at the origin and continues until the entire replicon has been replicated.
4. Bacterial chromosomes have a single replication origin, whereas eukaryotic chromosomes contain many.
5. The unwinding of the double helix generates a loop, termed a replication bubble .
6. The point of unwinding, where the two single nucleotide strands separate from the double-stranded DNA helix, is called a replication fork
7. If there are two replication forks, one at each end of the replication bubble, the forks proceed outward in both directions in a process called bidirectional replication.