Catalase breaks down and destroys hydrogen peroxide in two steps. The first step involves the catalase removing and binding one oxygen atom and releasing the rest of the hydrogen peroxide molecule as water. The second step is the catalase breaking down another hydrogen peroxide molecule by releasing oxygen gas and water. A pH of seven is optimal for human catalase activity to occur.
Catalase is part of almost every living cell. It is a hard-working enzyme that deactivates millions of hydrogen peroxide molecules every second. The enzyme breaks down hydrogen peroxide, which is produced during cell metabolism, to protect the cells from oxidative damage. There are four identical protein subunits that make up the catalase enzyme. These chains of protein subunits intertwine to form a stable structure, which is important because catalase must deal with hydrogen peroxide, a reactive compound. Each subunit of catalase includes an iron atom that binds the oxygen atom of hydrogen peroxide during its decomposition. Persons with catalase gene mutations have a metabolic disorder which often causes oral sores. The catalase enzyme's protection function helps prevent disease and possibly certain aging processes. As time goes by and a person ages, hydrogen peroxide builds up in the hair follicles and hair shafts, while concentrations of catalase slowly decrease, which results in the bleaching of hairs or grey hair.