In this section you will learn : All living things need to have
a source of chemical energy in order to live. A fuel is a
substance that can be used as a source of chemical energy.
Animals eat food as their fuel . Plants make food to act as
their fuel, using the energy of sunlight and a process called
photosynthesis. Both animals and plants then release the energy
from food by using the process of respiration. Respiration means
the release of energy from food. This is a process carried out
by all living things. The chemical process involved works most
efficiently if oxygen is used. Just like a fire needs an oxygen
supply to burn the fuel, so aerobic respiration needs oxygen.
Without oxygen the respiration does not release all the energy
and is called anaerobic respiration. If there is a plentiful
supply of oxygen then aerobic respiration takes place. When food
is burned to release energy using oxygen their are two waste
products produced. These are carbon dioxide and water. These are
the same waste products p