* Catalase and its Active Site: Catalase is an enzyme that breaks down hydrogen peroxide (H₂O₂) into water (H₂O) and oxygen (O₂). Its active site is specifically designed to bind to H₂O₂ molecules.
* Competitive Inhibition: The added substance, by binding to the active site, would act as a competitive inhibitor. This means it competes with the H₂O₂ for the same binding site on the enzyme.
* Reduced Enzyme Efficiency: As the inhibitor occupies the active site, it prevents H₂O₂ from binding and being catalyzed. This effectively reduces the number of active enzyme molecules available to catalyze the reaction, slowing down the overall reaction rate.
In summary: The addition of a substance that binds to the active site of catalase would act as a competitive inhibitor, decreasing the reaction rate by reducing the enzyme's ability to bind and catalyze the breakdown of hydrogen peroxide.
