Respiration is the process of breaking down glucose to release energy, which happens in every living cell.

It is not breathing in and out.

What is the energy in respiration used for?

• To build up larger molecules (like proteins)
• Contract muscles.
• Maintain a steady body temperature.

What is aerobic respiration?

What is its word equation?

Aerobic respiration is respiration that uses oxygen and is the most efficient way of releasing energy from glucose. 

Glucose + Oxygen -> Carbon Dioxide + Water (+Energy)

What is diffusion?

What is it used for?

Diffusion is the movement of particles from an area of higher concentration to and area of lower concentration.

When cells respire they use up oxygen and glucose, meaning the concentration is too low, whereas the concentration in the blood is high, so they diffuse from the capillaries to the cells.

They also produce lots of carbon dioxide in respiration, making the cell concentration high. It then diffuses into the blood, where concentration is lower.