Energy Transfer, Entropy, and Gibbs Free Energy

Chemical energy can only be transferred from one form to another; it cannot be created or destroyed.

Energy transfers are not 100% efficient.
During transfer from point A to point B, some energy will inevitably be lost.
This lost energy is typically dissipated as heat.
Example: In biological systems, every chemical reaction within an organism (like a cow) will release some energy as heat because it is not a perfectly conserved process.

Entropy: A measure of the disorder or randomness of a system.
In a closed system, entropy (S) will always increase over time.
Processes that break down complex molecules lead to increased disorder and thus higher entropy.
Example: When a complex carbohydrate is broken down, it becomes more disordered, resulting in an increase in entropy.

Gibbs Free Energy (\Delta G): Represents the amount of a system's energy that is available to do work (i.e., "free energy").
The formula for the change in Gibbs Free Energy is: \Delta G = \Delta H - T \Delta S
- \Delta G: Change in Gibbs Free Energy.
- \Delta H: Change in Enthalpy (which represents the total heat content of a system).
- T: Temperature (measured in Kelvin).
- \Delta S: Change in Entropy.

Exergonic Reactions:
- Indicated by a negative change in Gibbs Free Energy (\Delta G < 0).
- These reactions are spontaneous and release energy to the surroundings.
- In an exergonic reaction, the free energy of the products is lower than the free energy of the reactants.
Endergonic Reactions:
- Indicated by a positive change in Gibbs Free Energy (\Delta G > 0).
- These reactions are non-spontaneous and require an input of energy from the surroundings (they absorb energy).
- In an endergonic reaction, the free energy of the products is higher than the free energy of the reactants because energy is absorbed in the process.