Question

The enzyme photolyase is used in what method of repair?

(a) Base excision

(b) Photo reactivation

(c) Nucleotide excision

(d) None of the mentioned

This question was addressed to me in my homework.

My question is taken from DNA Repair in chapter DNA, RNA and Protein Metabolism of Biochemistry

Answer 1

The correct answer is:

(b) Photo reactivation

Photolyase is an enzyme involved in photo reactivation, a DNA repair mechanism. It specifically repairs UV-induced pyrimidine dimers (like thymine dimers) by using light energy, typically visible light, to reverse the dimerization, restoring the DNA to its original state. This process is common in some organisms like bacteria, fungi, and plants.