Which term describes reactions that absorb heat or require heat to be added?

The term that describes reactions that absorb heat or require heat to be added is "endothermic". In an endothermic reaction, the system takes in energy from its surroundings, typically in the form of heat. This leads to a decrease in the temperature of the surrounding environment since energy is drawn from it to facilitate the reaction. Common examples of endothermic reactions include photosynthesis and the dissolution of certain salts in water.

In contrast, the other terms provided refer to different types of reactions. For instance, "exothermic" reactions release heat to the surroundings, increasing the temperature of the environment. "Catabolic" refers to metabolic processes that break down molecules, releasing energy, while "oxidative" typically relates to reactions involving the loss of electrons, often coupled with the release of energy. Each of these terms has its own unique context and application, but when specifically addressing reactions that require the addition of heat, "endothermic" is the appropriate choice.