Understand what the oxygen cycle is, what it consists of and what its stages are. Also, its characteristics and importance.
What is the oxygen cycle?
The biogeochemical oxygen cycle is the set of processes by which oxygen circulates through planet Earth These processes can be physical, chemical, biological and geological.
During this cycle, oxygen is part of chemical compounds that change their state of aggregation (solid, liquid or gaseous), such as water (H2O), when it evaporates, condenses and freezes. Also Oxygen and its compounds can undergo chemical reactions such as the formation of ozone (O3) from diatomic oxygen (O2).
Besides, oxygen is part of living beings and through this cycle it is possible for this element to move from them to the environment that surrounds them and vice versa. Furthermore, geological processes, such as oxidation, also take part in this cycle, which allow oxygen to be transformed into different chemical forms that circulate on the planet.
The oxygen cycle is essential for maintaining life on planet Earth, since oxygen is the main chemical element in the respiration of living organisms. In addition, it is part of two molecules essential for life, water (H2O) and carbon dioxide (CO2).
Characteristics of the oxygen cycle
The oxygen cycle has specific characteristics that are related to the different processes involved in this cycle. In addition, this cycle is part of other biogeochemical cycles, such as the carbon cycle and the water cycle.
The main characteristics of the oxygen cycle are:
- It is part of some stages of the hydrological cycle (or water cycle), because oxygen is part of water (H2EITHER). The hydrological cycle also contributes to the circulation of oxygen on planet Earth. For example: evaporation is a stage of the hydrological cycle that occurs when water transforms from liquid to gaseous. This causes the oxygen present in liquid water to be transported into the atmosphere as part of gaseous water, and is then released from this molecule when it is impacted by solar radiation.
- It is part of the carbon cycle since oxygen is part of carbon dioxide (CO2) and carbon monoxide (CO), which are molecules that circulate on the planet during the carbon cycle.
- It is formed by biological processes (related to living beings), physical (related to changes in the state of aggregation and mixtures, among others), chemicals (related to the formation and decomposition of chemical compounds) and geological (related to natural phenomena that affect the structure, composition and shape of the Earth).
- It has a slow stage (involving biological processes) and a quick stage (which involves geological processes).
See also: Biogeochemical cycles
Stages of the oxygen cycle
The oxygen cycle is made up of several stages:
Rapid or biological stage
The biological stage of the oxygen cycle is the one that involves the biological processes that belong to living beings. It is made up of the following processes:
- Photosynthesis. It is the process by which some living organisms, such as plants, algae and phytoplankton, use carbon dioxide (CO2), water (H2O) and sunlight to obtain energy and produce its nutrients. As a result of photosynthesis, these organisms release oxygen (O2) to the atmosphere.
- Breathing. It is the process used by aerobic organisms (organisms that live and develop using oxygen) to incorporate oxygen (O2) to their bodies, while they expel carbon dioxide (CO2) to the environment that surrounds them.
Slow or geological stage
The geological stage of the oxygen cycle includes oxidation processes of some chemical elements and the decomposition of certain chemical compounds. It is made up of the following processes:
- Part of the hydrological cycle and atmospheric processes. The hydrological cycle is the circulation of water on planet Earth. This cycle is made up of several stages: evaporation, condensation, precipitation, infiltration and runoff. The evaporation of water is the transition from liquid water to gaseous water, and causes gaseous water to form in the atmosphere. One of the atmospheric processes that involves oxygen is related to the decomposition of gaseous water molecules present in the atmosphere when they interact with solar radiation, causing them to separate into hydrogen (H2) and oxygen (O2).
- Oxidation. Some chemical compounds are formed due to the oxidation of chemical elements. These compounds can then break down and release the oxygen. This is the case of mercury oxide (HgO), which is used in chemical laboratories and in the production of mercury. When HgO is heated, oxygen is released.
- Decomposition. Dead organisms are decomposed by the action of certain microorganisms that consume oxygen to carry out the decomposition and then release CO2.
Importance of the oxygen cycle
The oxygen cycle is very important for maintaining life on the planet, since aerobic living beings use oxygen to carry out the respiration process, which allows them to obtain the energy necessary to perform functions of their organism, such as moving and eating.
Besides, Oxygen is essential for the respiration of living organisms and for the decomposition of dead organisms.
On the other hand, oxygen is part of CO2which is used by plants to carry out photosynthesis, releasing molecular oxygen (O2) in the process. It is also part of water (H2O), which is the molecule essential for the life of all living beings.
References
- Torres, W. H. (2002). Biology of reactive oxygen species. Biochemical message, 2619-54.
- Flores, E.G. (2014). The basic bioelements of life. Logos Scientific Bulletin, 2-3.
- De la Llata Loyola, MD (2003). Ecology and environment. Progreso Editorial.
