Is the lagging strand discontinuous?
This enzyme can work only in the 5′ to 3′ direction, so it replicates the leading strand continuously. Lagging-strand replication is discontinuous, with short Okazaki fragments being formed and later linked together.
Why is DNA replication continuous and discontinuous?
a) For long DNA molecules, since the two strands of DNA cannot be separated in its entire length (due to very high energy requirement), polymerization takes place only in one direction which is 5′-3′, hence the replication occur within a small opening of the DNA helix, referred to as replication fork.
Why is the synthesis of the lagging strand discontinuous How is it different than the leading strand?
The strand formed from Okazaki fragments is termed the lagging strand, whereas the one synthesized without interruption is the leading strand. The discontinuous assembly of the lagging strand enables 5′ → 3′ polymerization at the nucleotide level to give rise to overall growth in the 3′ → 5′ direction.
What are the discontinuous segments called in the lagging strand?
Okazaki fragments
Due to the functional restriction of the DNA polymerase not being able to synthesize the chain in 3′ to 5′ direction, on the lagging strand, the synthesis of the chain is discontinuous in the 5′ to 3′ direction. The discontinuous replication results in several short segments which are called Okazaki fragments.
What is the difference between continuous and discontinuous replication?
Replication can only take place in the forward direction of each strand. As a result, one strand is copied continuously in the forward direction while the other is copied discontinuously in segments that are later joined.
Why does discontinuous replication occur?
On the upper lagging strand, synthesis is discontinuous, since new RNA primers must be added as opening of the replication fork continues to expose new template. In fact, DNA synthesis occurs as a single process involving a dimeric polymerase molecule situated at the RF.
What is the purpose of Okazaki fragments?
The purpose of Okazaki fragments is to allow DNA polymerase to synthesize the lagging strand in segments, since it is not oriented correctly for continuous synthesis.
How does discontinuous replication occur?
discontinuous replication The synthesis of a new strand of a replicating DNA molecule as a series of short fragments that are subsequently joined together. The other strand (leading strand) is synthesized by continuous addition of nucleotides to the growing end, i.e. continuous replication. …
Does the lagging strand go 3 to 5?
Lagging strand: Chunks of DNA, called Okazaki fragments, are then added to the lagging strand also in the 5′ to 3′ direction. This type of replication is called discontinuous as the Okazaki fragments will need to be joined up later.