exergonic

Examples of exergonic in the following topics:

• Activation Energy

  • Activation energy must be considered when analyzing both endergonic and exergonic reactions.
  • Exergonic reactions have a net release of energy, but they still require a small amount of energy input before they can proceed with their energy-releasing steps.
  • 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.
  • Important macromolecules, such as proteins, DNA, and RNA, store considerable energy, and their breakdown is exergonic.

• Free Energy

  • Reactions that have a negative ∆G and, consequently, release free energy, are called exergonic reactions.
  • Exergonic means energy is exiting the system.
  • Exergonic and endergonic reactions result in changes in Gibbs free energy.
  • Exergonic reactions release energy; endergonic reactions require energy to proceed.
  • Shown are some examples of endergonic processes (ones that require energy) and exergonic processes (ones that release energy).

• 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.
  • In this example, the exergonic reaction of ATP hydrolysis is coupled with the endergonic reaction of converting glucose for use in the metabolic pathway.
  • Sodium-potassium pumps use the energy derived from exergonic ATP hydrolysis to pump sodium and potassium ions across the cell membrane.

• Spontaneous and Nonspontaneous Processes

  • Endergonic reactions can also be pushed by coupling them to another reaction, which is strongly exergonic, through a shared intermediate.Saul Steinberg from The New Yorker illustrates a nonspontaneous process here.

• Citric Acid Cycle

  • This step is irreversible because it is highly exergonic.

• The Second Law of Thermodynamics

  • In an exergonic chemical reaction where energy is released, entropy increases because the final products have less energy inside them holding their chemical bonds together.

• 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.

• Solvent Effects

  • These different entropy changes are incorporated in the free energy of solution, which is exergonic for NaCl, but endergonic for CaF2.