Match LIST-I with LIST-II Choose the correct answer from the options given below:
Show Hint
Think of replication as road construction. \textbf{Helicase} is the bulldozer that separates the lanes. \textbf{Topoisomerase} is the crew that manages traffic jams (supercoils) up ahead. \textbf{DNA Pol III} is the paver laying down the new road (DNA). \textbf{DNA Pol I} is the repair crew that replaces the temporary starting cones (RNA primers) with permanent pavement (DNA).
Step 1: Understanding the Concept:
This question requires matching key enzymes and proteins involved in bacterial DNA replication with their specific functions in the process. Step 2: Detailed Explanation:
Let's match each protein from LIST-I with its function from LIST-II:
A. Helicase: This enzyme is responsible for separating the two strands of the DNA double helix, using ATP hydrolysis to power the unwinding process at the replication fork. This matches II. Unwinds parental double helix at replication forks.
B. DNA pol I: This DNA polymerase has a crucial "clean-up" role. It uses its 5' to 3' exonuclease activity to remove the RNA primers that initiated synthesis and its 5' to 3' polymerase activity to fill the resulting gaps with DNA. This matches I. Removes RNA nucleotides of primer...and replaces them with DNA nucleotides....
C. DNA pol III: This is the main replicative polymerase in bacteria. It is responsible for the rapid and processive synthesis of the new DNA strands, adding nucleotides to the 3' end of a primer. This matches IV. Using parental DNA as a template, synthesis new DNA strand by adding nucleotides....
D. Topoisomerase (specifically DNA gyrase in bacteria): As the helicase unwinds DNA, it creates positive supercoils (overwinding) ahead of the fork. Topoisomerase cuts the DNA, allows it to unswivel, and then reseals it to relieve this torsional strain. This matches III. Relieves overwinding strain ahead of replication forks....
Step 3: Final Answer:
The correct matching is A-II, B-I, C-IV, D-III.
