(3) Catalase
Catalase is a common enzyme found in nearly all living organisms which are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen. One molecule of catalase can convert millions of molecules of hydrogen peroxide to water and oxygen, per second. Catalase activity can be measured by either decomposition of H2O2 or by the liberation of O2 by UV spectrophotometric methods. The decrease in absorbance by hydrogen peroxide as a function of time is used to follow the catalaseperoxide reaction. The spectral wavelength for the determination of hydrogen peroxide is 240 nm. The difference in absorbance per minute is a measure of catalase activity [29, 33].