endergonic

(adjective)

Describing a reaction that absorbs (heat) energy from its environment.

Related Terms

Examples of endergonic in the following topics:

  • Free Energy

    • These chemical reactions are called endergonic reactions; they are non-spontaneous.
    • An endergonic reaction will not take place on its own without the addition of free energy.
    • Therefore, the chemical reactions involved in anabolic processes are endergonic reactions.
    • Exergonic and endergonic reactions result in changes in Gibbs free energy.
    • Exergonic reactions release energy; endergonic reactions require energy to proceed.

  • Activation Energy

    • Activation energy must be considered when analyzing both endergonic and exergonic reactions.
    • Cells will at times couple an exergonic reaction $(\Delta G<0)$ with endergonic reactions $(\Delta G>0)$, allowing them to proceed.
    • The free energy released from the exergonic reaction is absorbed by the endergonic reaction.
    • Whether the reaction is exergonic (ΔG<0) or endergonic (ΔG>0) determines whether the products in the diagram will exist at a lower or higher energy state than the reactants.
    • In this endergonic reaction, activation energy is still required to transform the reactants A + B into the product C.

  • ATP: Adenosine Triphosphate

    • Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions to harness the energy within the bonds of ATP.
    • ATP provides the energy for both energy-consuming endergonic reactions and energy-releasing exergonic reactions, which require a small input of activation energy.
    • Cells couple the exergonic reaction of ATP hydrolysis with the endergonic reactions of cellular processes.
    • By donating free energy to the Na+/K+ pump, phosphorylation drives the endergonic reaction.
    • In this example, the exergonic reaction of ATP hydrolysis is coupled with the endergonic reaction of converting glucose for use in the metabolic pathway.

  • ATP in Metabolism

    • In this way, ATP is a direct link between the limited set of exergonic pathways of glucose catabolism and the multitude of endergonic pathways that power living cells.
    • During an endergonic chemical reaction, ATP forms an intermediate complex with the substrate and enzyme in the reaction.