Required for Life
All living things use oxygen or depend on
organisms that use oxygen in some way.
All Animals and Other Consumers
We use oxygen to break down simple sugar
and release energy.
This can be done through respiration or
Animals mainly use respiration.
The process that breaks apart simple food
molecules to release energy.
It occurs inside cells.
What YOU do with the oxygen you take in.
Respiration in Cells
In our cells, oxygen is used to split glucose
apart — releasing energy, water and carbon
Plants take in carbon dioxide and water and
use them to make food. Their food is simple
sugar — glucose.
Plants pull the carbon off CO2 and use the carbon in
glucose. (They do not need the oxygen for this. They get that from water,
Plants release the oxygen (O2) back into the
Other organisms use the free oxygen for respiration.
How are photosynthesis and cellular
Photosynthesis uses carbon dioxide and produces
Cellular respiration uses oxygen and produces carbon
Rabbit gives off CO2,
which is taken in by the plant.
Rabbit eats food,
breaks it down
Plant uses CO2
to make food.
Plant gives off O2,
which is taken in by the rabbit.
This happens on land and in the water.
Algae and aquatic plants produce food underwater
They use CO2 dissolved in the water.
Other aquatic organisms use the dissolved oxygen
these plants release into the water.