The Oxygen Cycle

Oxygenis an important element to life on Earth. It is the most common element of the human body. It makes up about 65% of the mass of the human body. Most of this is in the form of water (H2O). Oxygen also makes up about 30% of the Earth and 20% of the atmosphere.

The Oxygen Cycle

Oxygen is constantly being used and created by different processes on planet Earth. All of these processes together make up the oxygen cycle. The oxygen cycle is interconnected with thecarbon cycle.

In the simple example of the oxygen cycle shown above, you can see how oxygen is used and cycled by plants and animals. Plants are the main creators of oxygen in the atmosphere through the process ofphotosynthesis. Here the tree uses sunlight and carbon dioxide to produce energy and releases oxygen. The giraffe breathes in the oxygen and then breathes out carbon dioxide. The plant can then use this carbon dioxide and the cycle is complete.

Simple diagram of the oxygen cycle

Processes That Use Oxygen Breathing - The scientific name for breathing is respiration. All animals and plants use up oxygen when they breathe. They breathe in oxygen and breathe out carbon dioxide. Decomposing - When plants and animals die, they decompose. This process uses up oxygen and releases carbon dioxide. Rusting - This is also called oxidation. When things rust they use up oxygen. Combustion - There are three things needed for fire: oxygen, fuel, and heat. Without oxygen you can't have a fire. When things burn, they use up oxygen and replace it with carbon dioxide.Processes That Produce Oxygen Plants - Plants create the majority of the oxygen we breathe through a process called photosynthesis. In this process plants use carbon dioxide, sunlight, and water to create energy. In the process they also create oxygen which they release into the air. Sunlight - Some oxygen is produced when sunlight reacts with water vapor in the atmosphere.Fun Fact Even though fish breathe under water they still breathe oxygen. Their gills extract the oxygen from the water. There is a lot of oxygen stored up in the oxide minerals of the Earth's crust. However, this oxygen isn't available for us to breathe. One of the biggest sources of oxygen is phytoplankton that live near the surface of the ocean. Phytoplankton are tiny little plants, but there are lots of them.

Oxygen Cycle

The oxygen cycle is the cycle that helps move oxygen through the three main regions of the Earth, the Atmosphere, the Biosphere, and the Lithosphere. The Atmosphere is of course the region of gases that lies above the Earths surface and it is one of the largest reservoirs of free oxygen on earth. The Biosphere is the sum of all the Earths ecosystems. This also has some free oxygen produced from photosynthesis and other life processes. The largest reservoir of oxygen is the lithosphere. Most of this oxygen is not on its own or free moving but part of chemical compounds such as silicates and oxides.

The atmosphere is actually the smallest source of oxygen on Earth comprising only 0.35% of the Earths total oxygen. The smallest comes from biospheres. The largest is as mentioned before in the Earths crust. The Oxygen cycle is how oxygen is fixed for freed in each of these major regions.In the atmosphere Oxygen is freed by the process called photolysis. This is when high energy sunlight breaks apart oxygen bearing molecules to produce free oxygen. One of the most well known photolysis it the ozone cycle. O2 oxygen molecule is broken down to atomic oxygen by the ultra violet radiation of sunlight. This free oxygen then recombines with existing O2 molecules to make O3 or ozone. This cycle is important because it helps to shield the Earth from the majority of harmful ultra violet radiation turning it to harmless heat before it reaches the Earths surface.In the biosphere the main cycles are respiration and photosynthesis. Respiration is when animals and humans breathe consuming oxygen to be used in metabolic process and exhaling carbon dioxide. Photosynthesis is the reverse of this process and is mainly done by plants and plankton.The lithosphere mostly fixes oxygen in minerals such as silicates and oxides. Most of the time the process is automatic all it takes is a pure form of an element coming in contact with oxygen such as what happens when iron rusts. A portion of oxygen is freed by chemical weathering. When a oxygen bearing mineral is exposed to the elements a chemical reaction occurs that wears it down and in the process produces free oxygen.These are the main oxygen cycles and each play an important role in helping to protect and maintain life on the Earth.

Oxygen CycleAll living things needoxygen. Oxygen is necessaryfor respiration;we inhale oxygen and breathe out carbon dioxide.Living cells needoxygen to create energy. Just like the hydrological cycle, oxygen is cycled in the environment.

Plants startthe oxygen cycle. Plants use solar energy for the process of photosynthesis to convert carbon dioxide and water into carbohydrates and oxygen. Plants take in oxygen and give out carbon dioxide.The other half of the cycle is happens with the animals. We take in oxygen to break carbohydrates into energy and give out carbon dioxide by the process of respiration. Thus, the oxygen produced by the plants is used by animals.

But this process of oxygen cycle is not as simple as it seems. Let us learn more in detail about the essential oxygen cycle.DefinitionThe biogeochemical cycle that describes about the movement of oxygen in the atmosphere (air), the biological matter of the ecosystem biosphere (the global sum of all ecosystems)and the lithosphere (earth's crust). The oxygen cycle helps the movement of oxygen in the three main regions of the earth, the atmosphere, biosphere and the lithosphere. It is the circulation of oxygen in various forms of nature. Oxygen is free in the air and dissolved in water.StepsAtmosphere is the region of gases about the surface of the Earth and it is one of the largest reservoirs of free oxygen. Biosphere is the total sum of all ecosystems and has some free oxygen which is produced by the process of photosynthesis and other life processes. Lithosphere is the largest reserve of oxygen. Most of the oxygen in thelithosphere is free moving and is a part of silicates and oxides of chemical compounds. The oxygen cycle describes about the free and fixed oxygen of the major spheres.

The oxygen cycle steps: The oxygen in the atmosphere is freed by the process of photolysis.The energy in the sunlight breaks the oxygen bearing oxygen to produce free oxygen. Oxygen molecule is broken down by UVrays from the sun. This cycle shields earth from harmful UVrays. In the biosphere, oxygen undergoes cycles of respiration and photosynthesis.Humans and animals breathe in oxygen. This oxygen is used in metabolic processes and carbon dioxide given out.Plants and phytoplanktonsundergo process of photosynthesis where carbon dioxide is used in the prescence of sunlight to form carbohydrates and oxygen. In the lithosphere, oxygen is fixed in minerals like silicates and oxides. Oxygen from these minerals isfreed by chemical weathering. When the mineral bearing oxygen is exposed to chemical reaction, the mineral wears down free oxygen is produced.DiagramThe pictorial illustration of the oxygen cycle is:

Oxygen cycle

Oxygen cycle

circulation of oxygen in various forms through nature. Free in the air and dissolved in water, oxygen is second only to nitrogen in abundance among uncombined elements in the atmosphere. Plants and animals use oxygen to respire and return it to the air and water as carbon dioxide (CO2). CO2is then taken up by algae and terrestrial green plants and converted into carbohydrates during the process of photosynthesis, oxygen being a by-product. The waters of the world are the main oxygen generators of the biosphere; their algae are estimated to replace about 90 percent of all oxygen used. Oxygen is involved to some degree in all the other biogeochemical cycles. For example, over time, detritus from living organisms transfers oxygen-containing compounds such as calcium carbonates into the lithosphere.Despite the burning of fossil fuel and the reduction of natural vegetation (on land and in the sea), the level of atmospheric oxygen appears to be relatively stable because of the increase in plant productivity resulting from agricultural advances worldwide.

Oxygen Cycle FactsOxygen Cycle FactsOxygen is an element that is very important to living organisms. It is created and used in different ways. The oxygen cycle shows these processes. The oxygen cycle is often interconnected with the carbon cycle because carbon and oxygen are often combined together in a molecule. The oxygen cycle basically consists of animals who inhale oxygen from the atmosphere and plants that release oxygen in the atmosphere.

Interesting Oxygen Cycle Facts:

Oxygen is basically cycled from plants to animals and then back to plants.

Respiration is the process by which animals breathe in oxygen.

When dead animals decompose, oxygen is used during the process.

The process of rusting, also called oxidation, occurs when oxygen combines with metal.

Without oxygen, fires would not be able to occur.

The majority of oxygen in the atmosphere is created by plants during photosynthesis.

Sometimes atmospheric oxygen is created when the sun reacts with water vapor.

Fish are able to pull out oxygen from water molecules in order to breathe under water.

Phytoplankton are tiny animals that live at the surface of the ocean and provide us with lots of oxygen.

Roughly 21% of the atmosphere is made of oxygen.

The more green plants and trees are cut down, the less supply of oxygen we have.

When plants create oxygen, they combine water with carbon dioxide releasing oxygen into the atmosphere.

When humans and other animals inhale oxygen, it combines with carbon from the food we eat and is exhaled as carbon dioxide.

Most oxygen is stored in minerals within the Earth's surface and is unavailable for use.

The sun is made up of roughly 1% oxygen.