Endoergicity

Endoergicity refers to a process that requires an input of energy to proceed. In thermodynamics, this is contrasted with exoergicity, where energy is released. An endoergic reaction or process has a positive Gibbs free energy change. This means that the system must absorb energy from its surroundings for the reaction to occur. Common examples include the synthesis of complex molecules from simpler ones, such as the formation of proteins from amino acids or the building of carbohydrate chains. Photosynthesis in plants is a classic biological example where light energy is converted into chemical energy stored in organic molecules. In chemical terms, endoergicity indicates that the products of the reaction are at a higher energy level than the reactants. While the reaction is not spontaneous, it can be driven by coupling it with an exoergic process that provides the necessary energy. This coupling is a fundamental principle in many biochemical pathways, allowing essential but energy-demanding reactions to take place within living organisms.