A catalytic reaction is a chemical process that occurs with the help of a substance called a catalyst. This catalyst speeds up the reaction without being consumed in the process, meaning it can be used repeatedly. Catalysts work by lowering the energy barrier needed for the reaction to take place, allowing reactants to convert into products more efficiently. These reactions are essential in various fields, including industrial chemistry and biochemistry. For example, enzymes are biological catalysts that facilitate reactions in living organisms, while catalysts in automobile exhaust systems help reduce harmful emissions.