Endothermic Reaction - GCSE Biology Definition

An endothermic reaction is a type of chemical reaction that absorbs energy from its surroundings, usually in the form of heat. In these reactions, the energy needed to break the bonds of the reactants is greater than the energy released when new bonds form in the products. As a result, the temperature of the environment around the reaction often falls, making it feel colder. An example of an endothermic reaction is photosynthesis, where plants absorb sunlight to turn carbon dioxide and water into glucose and oxygen. These reactions are the opposite of exothermic reactions, which release energy. Understanding endothermic reactions helps us see how living things, like plants, capture and use energy.