Question

What enzyme is used to unwind DNA?

Answer 1

Hint: These enzymes belong to a specific class of enzymes that help the DNA to unwind and unpack the individual’s genetic material. This unwinding of DNA then will result in the replication of DNA thus separating the DNA strands.

Complete answer:
The enzyme which is used to unwind DNA is the DNA helicase enzyme, which belongs to the class Helicase and is important for all the organisms. The DNA molecules consist of two DNA strands which will cause a hindrance in the process of the replication of the DNA thus these enzymes will separate the two strands forming a single-stranded DNA and then the DNA replication will occur. The separation of the two DNA strands takes place at the site of origin which will result in the formation of the replication fork. This unwinding of DNA occurs due to the breaking of the hydrogen bonds that are present in between the nitrogenous bases of the DNA molecule.
DNA is made up of nucleotide molecules. Every molecule of nucleotide contains one phosphate group, one sugar group, and one nitrogen base. The four types of nitrogen bases present in a nucleotide are adenine (A), thymine (T), guanine (G), and cytosine (C). Thymine is also known as 5-methyl uracil which is unique and in DNA. The nucleotides are attached to each other to form two long strands of DNA that spiral with each other to create a structure called a double helix.
The process of the synthesis of the new strand of DNA from the older one is called the DNA replication. Watson and Crick proposed a semi-conservative theory, in which they observed that the two strands of DNA molecules got separated during the process of replication and each strand acts as the format for the union of two strands. While the modern speculation concludes that the whole DNA molecule will act as a format for the union of a new strand.

Note:
In 1953 Watson and Crick proposed the double helix structure of DNA in 1953. Nikolai Koltsov was the first to anticipate the semiconservative model of the DNA and this model was later used by Meselson-Stahl in their experiment. They conducted an experiment to confirm that the DNA replicated through semi-conservative means with the help of two radioisotopes: nitrogen-15 (15N) and nitrogen-14 (14N).