Catalysts are molecules that lower the activation energy for a given reaction. cells produce their own catalysts called

Enzymes.

Explanation:

Enzymes are organic molecules of a protein nature and act on the chemical reactions of cells as catalysts, ie, speed up the processes without changing them. They are usually the most effective catalysts for their high specificity. Its quaternary structure will determine its function, to which substrate it will couple to accelerate a given reaction.

Our bodies are kept alive by a series of chemical chain reactions, which we call metabolic pathways, in which the product of a reaction later serves as a reagent. All phases of a metabolic pathway are mediated by enzymes.