Which of the following enzyme-function matches is incorrect?

• A. Helicase - relieves tension of supercoiling by breaking and rejoining ahead of fork
• B. Primase - provides short stretch of RNA at initiation of strand synthesis
• C. Polymerase – synthesizes new strand of DNA while using old strand of DNA as a template.
• D. DNA ligase - joins 3'-OH to 5'-phosphate to seal adjacent DNA nucleotides.

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the role of each enzyme mentioned in the problem. Helicase, Primase, Polymerase, and DNA Ligase are all involved in DNA replication, but each has a distinct function.
2. Step 2: Review the function of Helicase. Helicase is responsible for unwinding the DNA double helix by breaking hydrogen bonds between the complementary bases, creating a replication fork. It does not relieve supercoiling tension; that function is performed by topoisomerase.
3. Step 3: Examine the function of Primase. Primase synthesizes a short RNA primer that provides a starting point for DNA Polymerase to begin DNA synthesis. This description matches its correct function.
4. Step 4: Analyze the function of DNA Polymerase. DNA Polymerase synthesizes a new strand of DNA by adding nucleotides complementary to the template strand. This description is accurate.
5. Step 5: Verify the function of DNA Ligase. DNA Ligase seals nicks in the DNA backbone by joining the 3'-OH group of one nucleotide to the 5'-phosphate group of another, ensuring continuity of the DNA strand. This description is correct.