Biology – 5.1 Enzymes | e-Consult

A catalyst is a substance that speeds up the rate of a chemical reaction without being consumed in the reaction itself. It participates in the reaction mechanism but is regenerated at the end. This means the catalyst is not permanently changed.

A catalyst increases the rate of a reaction by providing an alternative reaction pathway with a lower activation energy. Activation energy is the minimum amount of energy required for a reaction to occur. By offering a different pathway, the catalyst lowers this energy barrier, allowing a greater proportion of reactant molecules to have sufficient energy to react. The catalyst binds to the reactants, forming an intermediate complex, which then breaks down into products, regenerating the catalyst in the process. This process allows the reaction to proceed faster.