Question

What is wrong with the following prediction: "if an organism produces a lot of catalase, then it has been selected strongly for it"?

Answer 1

Catalase is an important enzyme found predominantly in all living organism (eg: animals, plants and microorganisms like bacteria) exposed to oxygen. The main function of catalase is the breakdown of harmful substance, hydrogen peroxide (H2O2) to oxygen and water by catalytic reaction. In animals it is found in the liver. It proteccts cells from oxidative damage by reactive oxygen species (ROS) and increased life span. If catalase is not present, there is no breakdown of hydrogen peroxide (build up to toxic levels) and ROS can damage cell membranes, proteins and DNA.