1. By: Megan Reed, Annabel Lee, Brad Kim, and Dahlia Hage
THE OXYGEN CYCLE
By: Megan Reed, Annabel Lee, Brad Kim, and Dahlia Hage

2. Oxygen
Oxygen, one of the main components of the Earth’s atmosphere, can always be found with other elements.
Two oxygen atoms make up one oxygen molecule, and three oxygen atoms together make up the molecule called ozone.

4. Oxygen As a gas, oxygen is odorless, colorless, and highly reactive.
Oxygen is essential for the survival of many organisms, and, in the ozone, provides protection to life by filtering out the sun’s ultraviolet rays.

6. What is the Oxygen Cycle?
In the oxygen cycle, oxygen atoms present in the earth circulate through a series of intricate processes.
Like the nitrogen, carbon, and water cycles, the oxygen cycle is a biogeochemical cycle.
A biogeochemical cycle is the movement of matter through the biotic and the abiotic spheres of the ecosystem.

8. How do plants contribute?
The oxygen cycle begins with plants and photosynthesis.
Through photosynthesis, plants convert the energy from the sun and water into carbohydrates and oxygen.
During the day: plants convert carbon dioxide into oxygen.
During the night: plants convert oxygen into carbon dioxide to maintain their metabolism.

10. How does water contribute?
Oxygen in water is known as dissolved oxygen. When water runs over rocks, oxygen enters and creates a lot of high surface area which allows oxygen to transfer from the air into the water very quickly.

12. How do living organisms contribute?
Humans and animals breathe in oxygen and breathe out carbon dioxide through their processes of metabolism, sparking the process of photosynthesis, once again linking back to the plants’ contribution to the oxygen cycle.

14. The Three Main Reservoirs
The three reservoirs are the locations in which oxygen is found.
Biosphere (living things)
Lithosphere (Earth’s crust)
Atmosphere (air)

15. Biosphere and Atmosphere
Within the biosphere and atmosphere, plants begin the oxygen cycle and animals continue it.
Photolysis also donates to a large portion of the oxygen in the atmosphere, where high energy ultraviolet radiation breaks down the atmospheric water and nitrate.

17. Biosphere and Atmosphere
Much of the oxygen present in the atmosphere is used during respiration and decay mechanisms, where animal life and bacteria consume oxygen and release carbon dioxide.
Oxygen is also cycled between the biosphere and lithosphere.

19. Maintaining the Oxygen Cycle
There has been speculation by scientific experts that the oxygen cycle may be disturbed, and there may come a time when the amount of carbon dioxide is very large and there are too few plants to covert it into Oxygen
It is imperative that we reduce pollution and protect our environment in order to maintain a well functioning oxygen cycle.

21. Works Cited http://water.me.vccs.edu/concepts/oxcycle.jpg
Morris, R.M., OXYSPHERE - A Beginners' Guide to the Biogeochemical Cycling of Atmospheric Oxygen,
Fasullo, J., Substitute Lectures for ATOC 3600: Principles of Climate, Lectures on the global oxygen cycle,