When compounds lose electrons, they lose energy. When compounds gain electrons, they gain energy.
Oxidation occurs when a molecule loses an electron or increases its oxidation state. When a molecule is oxidized, it loses energy. In contrast, when a molecule is reduced, it gains one or more electrons. As you might have guessed, the molecule gains energy in the process.
Many components of the cell eventually wear out and need to be broken down and the parts recycled. This activity takes place inside the cell in specialized compartments called lysosomes.
