What is the Difference Between Lagging and Leading Strand?

The major difference between a lagging and leading strand is the direction and continuity of their replication during DNA replication. Here are the key differences between the two:

• Direction: The leading strand runs in the 5' to 3' direction, while the lagging strand runs in the 3' to 5' direction.
• Replication: The leading strand is replicated continuously, whereas the lagging strand is replicated discontinuously.
• Fragments: Short stretches called Okazaki fragments are formed during the replication of the lagging strand, while no short fragments are formed in the leading strand.
• Primer Requirements: The lagging strand needs a new primer every time a new fragment is synthesized, while the leading strand does not require new primers for continuous replication.

In summary, the leading strand is replicated continuously in the same direction as the movement of the replication fork, while the lagging strand is replicated discontinuously in the opposite direction, forming short Okazaki fragments.

Comparative Table: Lagging vs Leading Strand

The main difference between a lagging and leading strand is the direction of replication and the way they are synthesized. Here is a table comparing the two:

The lagging strand is synthesized discontinuously because the DNA polymerase moves away from the replication fork, causing it to come off and reattach to the newly exposed strand for each Okazaki fragment. In contrast, the leading strand is synthesized continuously, as the DNA polymerase moves in the same direction as the replication fork.