Origin of replication

Definition

The origin of replication is a specific sequence in the genome where DNA replication begins. It is essential for the initiation and proper regulation of DNA replication.

5 Must Know Facts For Your Next Test

1. In prokaryotes, there is usually a single origin of replication per circular chromosome.
2. The origin of replication is recognized by certain proteins that initiate the unwinding of DNA.
3. Eukaryotic chromosomes contain multiple origins of replication to ensure timely duplication of their larger genomes.
4. The origin recognition complex (ORC) binds to the origin of replication, marking it as a starting point for DNA synthesis.
5. Mutations in the origin of replication can lead to errors in DNA replication, potentially causing genomic instability.

Review Questions

• What role does the origin recognition complex (ORC) play at the origin of replication?
• How does the number of origins of replication differ between prokaryotic and eukaryotic cells?
• Why are multiple origins of replication necessary for eukaryotic chromosomes?

Related terms

Helicase: An enzyme that unwinds the DNA helix ahead of the replication fork.

Replication Fork: A Y-shaped region where new DNA strands are synthesized.

DNA Polymerase: An enzyme responsible for synthesizing new DNA strands during replication.