Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
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.
Verified step by step guidance
1
Understand the question: The problem asks you to identify which enzyme-function pair is incorrectly matched. Each enzyme listed plays a role in DNA replication, so we need to evaluate their functions carefully.
Review the function of Helicase: Helicase is responsible for unwinding the DNA double helix by breaking hydrogen bonds between complementary base pairs. It does not relieve tension caused by supercoiling; that is the role of topoisomerase.
Review the function of Primase: Primase synthesizes a short RNA primer to provide a starting point for DNA polymerase during DNA replication. This match is correct.
Review the function of DNA Polymerase: DNA polymerase synthesizes a new strand of DNA by adding nucleotides to the growing strand, using the old strand as a template. This match is correct.
Review 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. This match is correct. Based on this analysis, the incorrect match is Helicase, as its described function is actually performed by topoisomerase.