How is an endergonic reaction characterized?

An endergonic reaction is characterized by its requirement for an input of energy to proceed. This means that, unlike exergonic reactions, which release energy as they occur, endergonic reactions absorb energy from their surroundings. This energy absorption is necessary for the formation of products from reactants when the overall free energy change is positive. In biological systems, endergonic reactions are crucial as they often drive essential processes, such as the synthesis of complex molecules, where energy from sources like ATP is utilized.

Understanding this characteristic is key in disciplines like biochemistry and cellular biology, where the principles of energy transfer play a critical role in metabolic pathways. In essence, endergonic reactions reflect processes that require an energy input to move toward a state of higher free energy, enabling the formation of stable products from less stable reactants.