Your body needs glucose in order to release energy. Most of this comes from the digestion of carbohydrates.You also need oxygen. When you breathe in, oxygen enters the blood in the lungs and travels around the body in the bloodstream. The oxygen and glucose react in your body to produce carbon dioxide and water. The reaction gives out energy:
Glucose + Oxygen ---> Carbon dioxide + Water (+ energy)
This process is called respiration. Because it used oxygen, it is also known as aerobic respiration. The energy from aerobic respiration is needed to drive many processes into your body.
Example are muscle contraction, building proteins and sending messages through nerves.
Both glucose and oxygen pass from the blood into the cells by diffusion. Diffusion is the movement of molecules from an area where they are densely packed together (a high concentration) to an area where they are spread out (a low concentration).
Cells in the body are supplied with glucose…