Peroxidase is a catabolic enzyme originating from the turnip, used to break down hydrogen peroxide into oxygen and water. Different concentrations of peroxidase were tested with guaiacol, an oxygen indicator, to determine how the enzyme’s activity would be affected. Peroxidase, guaiacol, hydrogen peroxide, and distilled water were mixed together in test tubes and the color changes of the solution, showing the amount of oxygen produced, were recorded. The higher concentration of peroxidase had an apparent increase in enzyme activity rate and the lower concentration had an apparent decrease in rate compared to the standard concentration of peroxidase. Enzymes are biological catalysts that lower activation energy to speed up a chemical