Lagging strand

Definition

The lagging strand is the DNA strand that is synthesized discontinuously during DNA replication. It forms short segments called Okazaki fragments which are later joined together.

5 Must Know Facts For Your Next Test

1. The lagging strand is synthesized in the 5' to 3' direction but opposite to the replication fork movement.
2. Okazaki fragments are short DNA sequences formed on the lagging strand.
3. DNA ligase is responsible for joining Okazaki fragments to form a continuous strand.
4. Primase synthesizes RNA primers needed for the initiation of Okazaki fragment formation.
5. The lagging strand experiences more complex synthesis than the leading strand due to its discontinuous nature.

Review Questions

• What direction is the lagging strand synthesized in relation to the replication fork?
• What enzyme joins Okazaki fragments on the lagging strand?
• Why does the lagging strand require RNA primers?

Related terms

leading strand:

The DNA strand that is synthesized continuously in the same direction as the replication fork.

Okazaki fragments:

Short sequences of DNA nucleotides synthesized discontinuously on the lagging strand.

DNA ligase:

An enzyme that connects Okazaki fragments by forming phosphodiester bonds.