Energy is neither created nor destroyed, but can be transformed from one energy form to another. In other words, no one really "makes" energy; it has to come from somewhere. Also, no one really "uses up" energy; it has to go somewhere. Energy conversion is when energy is changed from one form to another.

Types of Energy

Chemical Energy - stored in chemical bonds; includes food, plants, and batteries (which produce electricity by combining chemicals)

Thermal Energy - heat energy; the end product of many transformations

Nuclear Energy - energy from radiation (atomic decay), fission (splitting atoms), or fusion (fusing atoms); makes huge amounts of energy

Mechanical Energy - energy of an object's motion (Kinetic Energy) or position (Potential Energy)

Electrical Energy - energy from moving electrons

Radiant Energy - light energy; actually electromagnetic radiation from light bulbs or the sun (actually the source of most power on earth).

Example of Energy Conversion

Thermal (heat) and radiant (light) energy are released when wood is burned. The wood has chemical energy.

Video segment. Assistance may be required. How are cellular respiration and photosynthesis involved in energy conversion? Watch the following video to see.

Source: Human Physiology : What Is Cellular Respiration?, eHow, YouTube