Elongation in DNA replication

Definition

Elongation in DNA replication is the process where nucleotides are added to a new strand of DNA, extending it in the 5' to 3' direction. This step occurs after the initiation phase and involves enzymes like DNA polymerase.

5 Must Know Facts For Your Next Test

1. DNA polymerase III is the primary enzyme involved in elongation during prokaryotic DNA replication.
2. Elongation proceeds by adding nucleotides complementary to the template strand.
3. The process requires a primer with a free 3'-OH group to begin nucleotide addition.
4. Proofreading mechanisms during elongation help ensure high fidelity in DNA replication.
5. In eukaryotes, DNA polymerases δ and ε play major roles in elongation on the lagging and leading strands, respectively.

Review Questions

• What role does DNA polymerase play in the elongation phase of DNA replication?
• Why is a primer necessary for elongation during DNA replication?
• How does proofreading contribute to the accuracy of DNA replication during elongation?

Related terms

Primer: A short nucleic acid sequence that provides a starting point for DNA synthesis.

DNA Polymerase: An enzyme that synthesizes new strands of DNA by adding nucleotides to an existing chain.

Leading Strand: The continuous strand of new DNA that is synthesized towards the replication fork.