The answer would be salt hydrolysis.
Salt that was made from the combination of weak and strong acid/base could be hydrolyzed and forming another substance. The hydrolysis process will separate the H2O into H+ and OH- and the weak part of the salt will take one of the ions(weak base will take OH-, weak acid will take H+). The result would be increased H+( or OH- ion, leading to change in pH of the solution.
Do you mean when nucleotides get damaged or when they match to each other incoreectly? (which cuases mutants) Specialized Enzymes repair, different one respond to help different types of damage. Detail the question more, maybe then i can help more.
