How does the enzyme catalase work?
The precise manner in which an enzyme lowers the activation energy of a reaction is not known, but current ideas are contained in the “induced-fit model” of enzyme action. This model (or idea) suggests that when an enzyme and substrate (we’ll consider a single substrate, but there may be more than one) interact to form an enzyme-substrate complex, the active site of the enzyme alters shape somewhat, and in so doing puts strain on bonds of the substrate molecule. The resultant form of the substrate requires less energy than a free substrate molecule to reach the transition state, which is the form of the molecule at the peak of the graphical plot of free energy against time. The chemical nature of the particular amino acids that form the boundaries of the active site is critical to the process, as the side-chains of these amino acids interact with the substrate.
