Energy
Energy balance is the homeostasis of energy in living systems. It is measured with the following equation:
Energy intake = internal heat produced + external work + storage.
When calculating energy balances in the body, energy is often measured in calories, with the definitions of a calorie falling into two classes:
- The small calorie or gram calorie (symbol: cal) approximates the energy needed to increase the temperature of 1 gram of water by 1 °C. This is about 4.2 joules.
- The large calorie, kilogram calorie, dietary calorie or food calorie (symbol: Cal) approximates the energy needed to increase the temperature of 1 kilogram of water by 1 °C. This is exactly 1,000 small calories or about 4.2 kilojoules.
Read more about this topic: Human Homeostasis
Famous quotes containing the word energy:
“Parents find many different ways to work their way through the assertiveness of their two-year-olds, but seeing that assertiveness as positive energy being directed toward growth as a competent individual may open up some new possibilities.”
—Fred Rogers (20th century)
“Just as we need to encourage women to test life’s many options, we need to acknowledge real limits of energy and resources. It would be pointless and cruel to prescribe role combination for every woman at each moment of her life. Life has its seasons. There are moments when a woman ought to invest emotionally in many different roles, and other moments when she may need to conserve her psychological energies.”
—Faye J. Crosby (20th century)
“Violence among young people ... is an aspect of their desire to create. They don’t know how to use their energy creatively so they do the opposite and destroy.”
—Anthony Burgess (b. 1917)