Question

explain the basic process of DNA synthesis (including the distinction between lagging strand and leading strand synthesis) and understand when DNA synthesis occurs

Answer 1

Answer:

Please the explanation below

Explanation:

DNA synthesis occur at the S phase of the cell cycle in preparation for cell division. The process which is also known as DNA replication occur in 3 main stages namely:

• Initiation
• Elongation
• Termination

At the initiation stage, the double helix DNA structure is unwound by DNA helicase enzyme to form a Y shape structure known as the replication fork. A short pieces of RNA called primer then binds to 3' end of the DNA strands at the starting point of replication.

During elongation, an enzyme known as DNA polymerase adds bases to the primer in the 5' to 3' direction. This makes the replication of the leading strand to be continuous. RNA primer binds to the lagging strand at multiple regions and are replicated in short disjointed fragments known as okazaki fragments. This kind of replication is discontinuous.

Termination involves the unbinding of RNA primer by an exonuclease enzyme. The primers are then replaced by relevant bases. Proofreading of the newly synthesized strands takes place and the okazaki fragments are joined together by an enzyme known as DNA ligase. Telomerase enzyme then adds telomeres to the end of the DNA strands and each newly synthesized strand winds to its parent strand.