Okazaki

Definition

Okazaki fragments are short sequences of DNA nucleotides synthesized discontinuously on the lagging strand during DNA replication. They are later joined together by DNA ligase to form a continuous strand.

5 Must Know Facts For Your Next Test

1. Okazaki fragments are synthesized in the opposite direction of the replication fork movement.
2. They are typically 100-200 nucleotides long in eukaryotes and about 1000-2000 nucleotides long in prokaryotes.
3. Their formation is necessary because DNA polymerase can only synthesize DNA in a 5' to 3' direction.
4. RNA primers initiate the synthesis of Okazaki fragments.
5. DNA ligase is responsible for joining Okazaki fragments into a continuous strand.

Review Questions

• What role do RNA primers play in the formation of Okazaki fragments?
• Why are Okazaki fragments shorter in eukaryotes compared to prokaryotes?
• Which enzyme is responsible for joining Okazaki fragments?

Related terms

Lagging Strand: The strand of DNA that is synthesized discontinuously during replication.

DNA Ligase: An enzyme that joins Okazaki fragments together by forming phosphodiester bonds.

RNA Primer: A short segment of RNA used to initiate synthesis of a new strand of DNA during replication.