Question

Helicase cannot initiate the unwinding of double stranded DNA; the initiator proteins first separate DNA strands at the origin, providing a short stretch of single stranded DNA to which the helicase binds. Helicase binds to the _______________ strand template at each replication fork and moves in the 5 to 3 direction along the strand thus also moving the replication fork.

Answer 1

DNA helicase binds to single-stranded DNA at the origin of replication, unwinding the double helix and allowing replication to proceed. It moves in the 5' to 3' direction along the strand. Topoisomerase, single-strand binding proteins, and primase are also essential in coordinating DNA replication.

Step-by-step explanation:

Helicase is an essential enzyme in the process of DNA replication as it separates the DNA strands at the origin of replication. When helicase is mutated, the DNA strands cannot be separated at the beginning of replication, which disrupts the replication process. Topoisomerase works ahead of the replication fork, breaking and reforming the DNA's phosphate backbone to relieve the supercoiling pressure. Single-strand binding proteins prevent the DNA from re-forming a double helix. Primase synthesizes an RNA primer, which DNA polymerase III uses to synthesize the daughter DNA strand. On the leading strand, DNA is synthesized continuously, whereas on the lagging strand, it is synthesized in short stretches known as Okazaki fragments.