AP Biology Chapter 8- FREE ENERGY

Symbol for free energy


Equation for change in free energy

^G = ^H - T^S

If a process has a negative ^G it is


Free energy measures

a system's instability

During a spontaneous change...

Free energy decreases and stability increases

Equilibrium is a state of

maximum stability

A spontaneous process can only perform work when

it is moving towards equilibrium

Three examples of Spontaneous processes

Gravitational motion, diffusion, a chemical reaction.

EXERgonic reaction:

a release of free energy. Spontaneous

ENDERgonic reaction:

absorbs free energy from its surroundings. Nonspontaneous

^G<0 =


^G>0 =


Closed systems do no work when

They have reached equilibrium

What two things will never reach equilibrium

Cells and metabolism

What releases free energy

Catabolic pathways