Did you know that...
not all cell types use the same amount of energy?
The human body is made up of billions of cells. All cells need energy to carry out their basic activities. This energy comes from breaking the chemical bonds of the molecules in the foods we eat. But because cells are specialized for specific tasks, they each need different amounts of energy each day. For example, in an adult the brain makes up only about 2 percent of the body's total weíght, but it uses about 20 percent of the body's total energy when the body is at rest. Much of this energy is used for powering the nerve impulses in its many brain cells. The liver also uses about 20 percent of the body's total energy. The heart uses about 10 percent of the body's energy and the skeletal muscles use about 20 percent of the body's energy when at rest, but the amount of energy required for the cells in these organs rises significantly when the body is physically active.
