Respiration is just breathing, right? Wrong! Respiration is the chemical process that supplies the body with energy for all other life processes, growth and repair of cells, muscle contraction, protein synthesis, sending nerve impulses, absorbing molecules in active transport to name just a few. It happens in all living cells, not just animal cells, but also plant cells. There are two types of respiration. Aerobic and anaerobic respiration. Aerobic means with air, and so needs oxygen, whereas anaerobic respiration doesn't need oxygen. Let's start by looking at aerobic respiration. Aerobic respiration releases energy in cells by breaking down food substances whilst in the presence of oxygen. It is represented by this simplified equation. But don't forget the energy which is released. Glucose is broken down by oxygen to release the byproducts of carbon dioxide and water. Energy is released, which is then used to make a special energy molecule called ATP. ATP is how energy is stored for later use by the body. Aerobic respiration happens all the time in all cells, usually in the mitochondria. Animals get the oxygen needed from the air through their ventilation systems. Plants get their oxygen from the air through the stomata. Do you remember how photosynthesis works? Compare these two equations. You can hopefully see that aerobic respiration works in the opposite way to photosynthesis. Plants produce their food by photosynthesis, and then through respiration release energy from it. But don't be confused, whilst plants do release oxygen as a byproduct of photosynthesis, they don't necessarily take in this oxygen for respiration. They just take in any oxygen from the air. Plants respire throughout the day and night as their animals. But they only photosynthesize during the day, when there is light available. So this is how aerobic or with air respiration works. You just need to remember that glucose is broken down in the presence of oxygen to release carbon dioxide, water and energy. In the next video, we will have a look at anaerobic respiration and how it differs.