What is Free Energy in Biochemistry? Definition – Types and Importance
Introduction
In biochemistry, living organisms constantly perform thousands of chemical reactions to maintain life. These reactions require or release energy. The concept of free energy helps scientists understand whether a biochemical reaction can occur spontaneously and how much useful energy is available to do biological work.
Free energy is especially important in processes such as:
- Cellular respiration
- ATP synthesis
- Muscle contraction
- Active transport
- Protein synthesis
The most important form studied in biochemistry is Gibbs Free Energy.
Definition of Free Energy
Free energy is the amount of energy available in a system to perform useful work at constant temperature and pressure.
In biochemistry, it refers to the energy that can be used by cells for biological processes.
Where:
- ΔG = Change in Gibbs free energy
- ΔH = Change in enthalpy (heat energy)
- T = Absolute temperature
- ΔS = Change in entropy (disorder)
Gibbs Free Energy
Definition
Gibbs free energy is the energy associated with a chemical reaction that can be used to do useful work.
It predicts whether a reaction will occur spontaneously or not.
Interpretation of ΔG
| Value of ΔG | Meaning |
|---|---|
| ΔG < 0 | Reaction is spontaneous |
| ΔG > 0 | Reaction is non-spontaneous |
| ΔG = 0 | Reaction is at equilibrium |