| Form of energy | Example in biology |
|---|
| Chemical: Stored in bonds | Chemical energy stored in covalent bonds is released during the hydrolysis of polymers |
| Electrical: Separation of charges | Electrical gradients across cell membranes help drive the movement of ions through channels |
| Heat: Transfer due to temperature difference | Heat can be released by chemical reactions, and this can alter the internal temperature of an organism |
| Light: Electromagnetic radiation stored as photons | Light energy is captured by pigments in the eye and by plant pigments in photosynthesis |
| Mechanical: Energy of motion | Mechanical energy is used in muscle movements and movements within cells |