Which component is affected when a catalyst is added to a chemical reaction

A catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

Catalysts increase the rate of reaction without being used up. They do this by lowering the activation energy needed. With a catalyst, more collisions result in a reaction, so the rate of reaction increases. Different reactions need different catalysts.

Many important chemical reactions require inputs of energy to proceed. If a catalyst is present less energy will be required to complete the reaction. Catalysts are substances that are mixed in with materials that are to be reacted, but they themselves do not, in the end, change chemically.

SO, a catalyst will increase the rate of reaction of any component.