Question

DNA gyrase, the enzyme that participates in the process of DNA replication is a type of
A. DNA topoisomerase
B. Reverse transcriptase
C. DNA ligase
D. DNA polymerase

Answer 1

Hint: DNA replication means making copies of DNA. Several enzymes are required for the process of DNA replication. Moreover, the enzyme DNA gyrase has an important role in the unwinding of the DNA helix structure.

Complete answer:
The enzyme DNA gyrase plays an important role in the process of DNA replication during the Unwinding of the helix of the DNA. The unwinding of the double-helical parent molecule of the DNA occurs with the help of the helicase enzyme. Helicase is an ATP-dependent enzyme. The unwinding of the DNA molecule results in the formation of the replication fork. The replication fork is a Y-shaped structure. In the replication fork, the single strands are exposed. These exposed single strands are stabilized by the single-strand binding protein or SSBP. The unwinding of the DNA helix at the bottom creates supercoiling at the top. This is like a knot in the string when the respective threads are unwound. To release this tension the enzyme topoisomerase is used in the eukaryotic organisms. However, in the case of the prokaryotic organisms, the enzyme topoisomerase is not present. Its function is fulfilled by the enzyme DNA gyrase. Thus, in prokaryotes, the enzyme DNA gyrase has a topoisomerase activity.
Thus, DNA gyrase, the enzyme that participates in the process of DNA replication is a type of DNA topoisomerase.

Hence, the correct answer is option (A).

Note: Whole DNA does not unwind together. The DNA is made up of stable Hydrogen bonding. Due to this reason, DNA unwinds in segments. On one strand it is continuous unwinding, whereas on the other strand discontinuous unwinding occurs and a replication fork is created.