Exergonic to Endergonic and vice-versa
Catabolic to Anabolic and vice-versa
Energy coupling: transfer of energy from one reaction to another in order to drive the second reaction.
Exergonic reactions: delta G ≤ 0, spontaneous, release free energy
Endergonic reactions: delta G ≥ 0, Non-sponatneous, absorbs free energy.
Example: 6th and 7th step of glycolysis
