origin of replication

In genetics, the origin of replication is the specific site on a DNA molecule where the process of DNA replication begins. This is a crucial step before a cell can divide, ensuring that genetic information is accurately duplicated for daughter cells.

In prokaryotes, like Escherichia coli, replication starts at a single origin and proceeds bidirectionally around the circular DNA molecule. Eukaryotes, however, have much longer chromosomes and initiate replication at multiple origins simultaneously to complete the process efficiently. Enzymes like helicases unwind the DNA double helix, and DNA polymerases then synthesize new strands using the original strands as templates, following a semiconservative model where each new DNA molecule consists of one old and one new strand.12