We need energy - How does respiration work? Information for learners
We eat food to give us energy and this energy is used for certain processes in our bodies like growing, repairing parts of the body that is hurt or infected, to be able to move and do our daily tasks and also to control the body's temperature.
These different processes in living organisms are called 'live processes'.
Refresh your memory again on the different life processes.
Breathing is one of the life processes and this means gasses are going in and out of the lungs, but there is another process taking place in the cells which are often confused with breathing/ventilation, and that is 'respiration'.
For breathing you will need your lungs, the tubes that goes from your mouth to your lungs and also different structures in your body that helps with the movement of oxygen and carbon dioxide in and out of the body.
Respiration takes place in the cells and this happens when the energy is released from the glucose so that all the other processes can take place.
What is the difference between breathing and respiration? Breathing is the physical process where you inhale and exhale air in and out of your lungs. ...Respiration is a chemical reaction where Oxygen is used to breakdown Glucose in order to generate energy which is then used by the cell to function. 
There are two types of respiration called aerobic respiration and anaerobic respiration - the first one tells you it happens in the presence of oxygen and anaerobic takes place in the absence of oxygen.
During aerobic respiration, the glucose and the oxygen reacts together in the cell and gives off water and carbon dioxide. During this reaction the energy is released which will be used in the mitochondria of the cell to perform certain 'activities'.
During anaerobic respiration the glucose will be turned into lactic acid because there are no oxygen present. Ever exercised very hard and you are stiff the next day? Blame it on anaerobic respiration and the lactic acid in your muscles. During the exercise your cells in your body did not get enough oxygen.
Anaerobic respiration are used in the food industry in baking bread and brewing wine and beer. Yeast is a fungi and if it is mixed with sugar, it will use the glucose and will give off ethanol and carbon dioxide.
For more information on the role of yeast you can read here.
In short - in order for you body to perform the different processes, it needs energy which means you will need food. The glucose in the food is broken down, energy is given off and the cells can do what they have to. This is called respiration.
