The “lagging strand” is synthesized in the direction away from the replication fork and away from the DNA helicase unwinds. Why is there a lagging strand in DNA replication? Why must there be a lagging strand during DNA synthesis? Explanation: The lagging strand exists because DNA is antiparallel and replication always occurs in the 5′ to 3′ direction. This leads to the formation of Okazaki fragments. As DNA polymerase can only add nucleotides in 5’→3′ direction of the growing strand, the lagging strand has to be synthesized discontinuously away from the replication fork. Okazaki fragments are necessary for the replication of both strands simultaneously. What are Okazaki fragments and why are they necessary? Polymerase I then removes RNA primers and fills the gaps between Okazaki fragments. Polymerase I In prokaryotic cells, polymerase III is the major replicative polymerase, functioning in the synthesis both of the leading strand of DNA and of Okazaki fragments by the extension of RNA primers. Which DNA polymerase removes Okazaki fragments? Okazaki fragments are short sequences synthesized in the lagging strand because DNA polymerase can synthesize only from 5′ to 3′, and the DNA strands are antiparallel. Which of the following statements best describes Okazaki fragments? They are formed in the lagging strand. Which best describes Okazaki fragments in DNA replication? On the lagging strand, DNA synthesis restarts many times as the helix unwinds, resulting in many short fragments called “Okazaki fragments.” DNA ligase joins the Okazaki fragments together into a single DNA molecule. On the leading strand, DNA synthesis occurs continuously. How does the Okazaki fragments occur for DNA replication? They are important because they allow for both daughter strands to be synthesized, which are necessary for cell division. On the lagging strand, DNA ligase joins Okazaki fragments by forming phosphodiester bonds between them, thus completing DNA replication.Okazaki fragments are small sections of DNA that are formed during discontinuous synthesis of the lagging strand during DNA replication. DNA polymerase I removes the RNA primers and replaces them with DNA nucleotides. ![]() Primase creates short RNA primers, initiating DNA synthesis on both template strands. ![]() DNA polymerase III synthesizes the new strands, but it requires an existing 3′ hydroxyl (-OH) group to add nucleotides. Single-strand binding proteins bind to the single strands of DNA, preventing them from re-forming hydrogen bonds with each other and allowing synthesis to occur on both strands. ![]() Helicase breaks the hydrogen bonds between the parental DNA strands and unwinds the double helix. Several proteins are involved in DNA replication, including the following: Topoisomerase cuts, swivels, and rejoins DNA strands ahead of the replication fork. On the other template strand, DNA is synthesized away from the replication fork in segments called Okazaki fragments, generating the lagging strand. On one template strand, synthesis proceeds continuously toward the replication fork, generating the leading strand. During replication, DNA synthesis occurs in the 5′ to 3′ direction along both template strands.
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