sickofliberals

Fuel is any material that is capable of releasing energy when its chemical or physical structure is changed or transformed. Fuel releases its energy either through chemical means, such as burning, or nuclear means, such as nuclear fission or nuclear fusion. An important property of a useful fuel is that its energy can be stored to be released only when required, and that the release is controlled in such a way that the energy can be harnessed to produce work.
All carbon-based life forms—from microorganisms to animals and humans—depend on and use fuels as their source of energy. Their cells engage in an enzyme-mediated chemical process called metabolism that converts energy from food or solar power into a form that can be used to sustain life. Additionally, humans employ a variety of techniques to convert one form of energy into another, producing usable power for purposes that go far beyond the energy needs of a human body. The application of energy released from fuels ranges from heat to cooking and from powering weapons to propulsion and production of electricity.