respiration (thing)

Respiration takes place in the mitochondria of every cell in your body. It is the process of converting glucose and oxygen into energy.

Aerobic respiration

This is the sort of respiration that takes place where plenty of oxygen is available. It is the ideal way to convert glucose into energy.

Glucose + Oxygen -> Carbon Dioxide + Water + Energy
C₆H₁₂ + 6O₂ -> 6CO₂ + 6H₂O + Energy

Anaerobic respiration

This is what happens when there's not much oxygen available. It's not a very good way of converting glucose to energy.

Glucose -> Energy + Lactic Acid

This type of respiration takes place when you exercise a lot and your body can no longer supply enough oxygen to your muscles. Your body has to convert the lactic acid back into harmless carbon dioxide and water after you stop exercising.