The term endergonic refers to chemical reactions that require energy input to proceed. In these reactions, the energy of the products is greater than the energy of the reactants, indicating that energy has to be absorbed from the surroundings for the reaction to happen. This is in contrast to exergonic reactions, where energy is released spontaneously.
Endergonic reactions are essential for various biological processes, such as synthesizing complex molecules from simpler ones (e.g., photosynthesis, protein synthesis), where the absorption of energy is necessary to drive these processes forward.
Understanding endergonic processes is crucial in the context of biological systems since they often couple with exergonic reactions to make them energetically favorable overall.