Exergonic and endergonic reactions are fundamental types of chemical reactions that take place in living organisms, each playing a crucial role in energy management.

Exergonic Reactions
Exergonic reactions are characterized by the release of energy. In these reactions, the reactants possess a higher potential energy compared to the products. The energy difference between the reactants and products is released, often in the form of heat or light. This released energy can then be harnessed by cells to perform various biological functions, such as muscle contraction and the synthesis of adenosine triphosphate (ATP). A prime example of an exergonic reaction is the breakdown of glucose during cellular respiration, along with the hydrolysis of ATP to adenosine diphosphate (ADP):

Endergonic Reactions
Conversely, endergonic reactions require an input of energy to occur. In these reactions, the reactants have a lower potential energy than the products, necessitating energy from an external source to drive the reaction forward. This energy can be derived from various origins, such as light energy in photosynthesis or the breakdown of ATP. Notable examples of endergonic reactions include the synthesis of glucose during photosynthesis:

and the formation of proteins from amino acids:

Importance of Exergonic and Endergonic Reactions
Together, exergonic and endergonic reactions are vital for maintaining the energy balance within living organisms. Exergonic reactions release energy that can be utilized for various cellular processes, while endergonic reactions depend on energy input to function. A comprehensive understanding of these reactions is essential for grasping the metabolic processes that sustain life.