Question

Which strand undergoes leading strand synthesis in rolling circle replication? Which strand undergoes lagging strand synthesis?

Answer 1

In rolling circle replication, the leading strand is synthesized in the direction of the replication fork, while the lagging strand is synthesized away from the fork, in short segments called Okazaki fragments.

Step-by-step explanation:

In rolling circle replication, the leading strand synthesis occurs in the direction of the replication fork, and the lagging strand undergoes synthesis in the direction away from the replication fork, in short stretches called Okazaki fragments.

During rolling circle replication, the enzyme DNA polymerase reads the parental DNA strand in the 3' to 5' direction and adds nucleotides only in the 5' to 3' direction. The leading strand is synthesized continuously, in a direction that follows the replication fork. The lagging strand, on the other hand, is synthesized discontinuously away from the replication fork. This is made possible by the creation of multiple RNA primers by primase, which allows DNA polymerase to synthesize the short DNA fragments known as Okazaki fragments. These fragments are later joined together by the enzyme DNA ligase, ensuring the integrity of the lagging strand.