Answer the following questions concerning the accuracy of DNA polymerase during replication.

If a DNA replication error is detected by DNA polymerase, how is it corrected?

Key Concepts

DNA Polymerase Function

DNA polymerase is an enzyme responsible for synthesizing new DNA strands during replication. It adds nucleotides to a growing DNA chain by matching them with the template strand. Its ability to accurately incorporate the correct nucleotides is crucial for maintaining genetic fidelity.

Proofreading Mechanism

DNA polymerase possesses a proofreading function that allows it to detect and correct errors during DNA synthesis. When an incorrect nucleotide is added, the enzyme can reverse its activity, excising the mismatched nucleotide before resuming synthesis with the correct one. This process significantly reduces the mutation rate.

Mismatch Repair System

In addition to the proofreading activity of DNA polymerase, cells have a mismatch repair system that identifies and repairs errors that escape proofreading. This system involves several proteins that recognize distortions in the DNA helix caused by mismatched bases, excise the erroneous segment, and fill in the correct nucleotides, ensuring genomic stability.