What type of chemical reaction do catalysts influence?

Catalysts are substances that accelerate chemical reactions without undergoing any permanent chemical change themselves. They work by providing an alternative reaction pathway with a lower activation energy, which allows more molecules to collide with enough energy to react. This alteration significantly increases the reaction rate, meaning that the reaction occurs more quickly compared to a scenario without a catalyst.

While catalysts can influence various types of reactions—including both endothermic and exothermic reactions, as well as redox reactions—they are specifically defined by their effect on the speed of reactions rather than the nature of the reactions themselves. Thus, the correct answer focuses on how catalysts affect the reaction rate, which is a critical aspect of their function in chemical kinetics.