The nitrogen cycle is one of the most important processes that occur on our planet. In fact, it has different stages that are essential for the development of life of any kind. Next, we will talk about its characteristics, importance and each of the stages it fulfills.
What is the biogeochemical nitrogen cycle?
By definition, the nitrogen cycle consists of a closed set of different abiotic and biological processes. It has the objective of providing this chemical compound (Nitrogen) to all living beings, whether they are plants, animals or human beings.
This biogeochemical cycle is one of the most relevant on the planet, fulfilling a variety of functions that make life possible. Even the dynamic equilibrium depends on nitrogen and its processes done in the biosphere.
Characteristics of the biogeochemical cycle of nitrogen
The nitrogen It is a chemical compound that originated by creating new atomic nuclei. Scientific and chemical studies have discovered that stars composed of huge masses of helium gave way to the production of nitrogen. When the right conditions of temperature and pressure were reached, this chemical element was formed.
Once the planet’s volcanic activity increased in intensity, nitrogen was converted to a gaseous state. Subsequently, it was integrated into the atmosphere, where it began to carry out its biogeochemical cycle. Nitrogen manifests itself in different ways through chemical processes that originate from losing electrons.
nitrogen manifestations
Firstly, nitrogen is present organically in proteins and amino acids of the organism. On the other hand, it also exists in organic compounds, such as ammonia, nitrates, nitrites and the ammonium ion.
It is thought that ammonia arises due to the biological and chemical cycles of nitrogen that have occurred over the years. These processes are related to the interaction between volcanic and maritime activities.
Explanation of the nitrogen cycle
The processes that take place in the biogeochemical cycle of nitrogen they are quite complex. In fact, each of the stages has different characteristics that contribute to a greater or lesser extent to its production and assimilation. In any case, there are five steps that the cycle takes and each one is of vital importance.
Nitrogen fixation
This is where the process begins. transformation of atmospheric nitrogen. Thus it can be used by living beings through chemical reactions that need large amounts of energy. These are obtained through channels abiotic Y Biotics.
During the nitrogen fixation stage, the bonds present in the molecules of the atmospheric chemical component are broken.
Ammonification
The nitrogen it is present in organic matter, which includes animal waste and dead organisms. Urea, mammalian urine, and uric acid found in bird droppings may be included. In the process of ammonification, all nitrogen compounds in the soil are reduced to simpler chemical compounds.
This is achieved when the microorganisms generate proteins through the amino acids of each composition. As a consequence, the release nitrogen which was accumulated in excess, albeit in the form of ammonium ion either ammonia. Therefore, bacteria will be able to intervene in the later stages of the cycle.
Nitrification
It is the phase where the bacteria take up the ammonium ion and the ammonia available in the substrate to produce oxidation. In this way, the energy of the metabolisms is used. In the oxidation process, bacteria make nitrites especially those of the genus Nitrosomes.
then the holm oak ammonia mooxygenase is activated in microorganisms, generating NH3 oxide, giving way to the hydroxylamine. As in the previous case, it is a compound reduced to nitrite through oxidation.
Over the course of the cycle, the nitrite becomes into nitrate, again for the oxidizing effects of the bacteria Y enzymes. Finally, the compounds remain lodged in the soil, so that they can be absorbed by the plants for nutrition.
Denitrification
In this phase, both nitrates Like the nitrites that are produced through oxidation they turn into atmospheric nitrogen. At the same time, a slight amount of nitrous oxide. There are certain very relevant criteria for this stage to be carried out correctly.
Soil saturation and temperature have a direct influence, as does the intervention of anaerobic bacteria. It is what allows the assimilation of electrons to return nitrogen to the atmosphere. With this, the cycle is optimally closed.
Assimilation
Certain plants absorb nitrogen from the soil through nitrates present in the roots. No bacteria or fixing intermediates intervene atmospheric nitrogen. One of the parts of the nitrates entered is used by the roots to distribute xylem, reaching the plant structure in its entirety.
If nitrate is to be used, it is reduced to nitrite by the action of the nitrate enzyme reductase. Subsequently, the nitrite is carried to an area of the plant called chloroplasts, where it is reduced to aion ammonium. So, they form molecules and amino acids, which will be taken by living beings as food.
Importance of the nitrogen cycle
The biogeochemical cycle of nitrogen It is of great relevance to life on the planet. Thanks to it, different biological processes are involved that are essential for living organisms. Helps the production of amino acids, proteins Y nucleic acids.
It is true that the nitrogen It is found abundantly in the atmosphere, but there are some limitations. Very few organisms can directly assimilate the chemical compound. For this reason, the planet carries out its biogeochemical cycle, so that the compound is treated and prepared to be assimilated.
Nitrogen cycle in water or marine ecosystems
The biogeochemical cycle of nitrogen It is not only present in terrestrial ecosystems. It also plays an indispensable role in the marine ecosystems present in the hydrosphere. However, the processes are very similar to those we have already described above.
ammonification, denitrification Y nitrification they are still a priority. In aquatic ecosystems, these processes are carried out by archaea and bacteria marine. Many of the nitrogen compounds fall to the ocean surface as sediments.
Over very long periods of time, these sediments are compressed into sedimentary rocks. Subsequently, geological uplift moves the rocks back to the Earth’s surface.
scientific investigations
Previously, scientists did not think of oceanic sedimentary rocks as a rich source of nitrogen. However, as the years have progressed, new scientific studies have shown that they have a direct influence on the terrestrial ecosystems.
The nitrogen is released gradually as the rocks suffer wear or know weather. As a result, it becomes available for uptake by plants.
Nitrogen cycle in the human body
The Humans we do not have the capacity fix nitrogen in a biological way. We can enjoy its properties thanks to biogeochemical cycle What does this chemical compound do? Now, this is not to say that humanity has not had an impact on the production and use of nitrogen in the environment.
Industrially, approximately 450 million tons of nitrogen year. Different chemical compounds are reacted at high temperatures to be used in large companies. Much of that amount of nitrogen is used for the production of fertilizers.
How does human activity affect the nitrogen cycle?
There are two main means by which human activity achieves the release of nitrogen into the environment. The first is the burning of fossil fuels, and the second the use of nitrogen fertilizers. In both processes, the levels of nitrogenous compounds are increased in the atmosphere.
The concentrated levels of atmospheric nitrogen are associated with harmful effects on the health of the planet. For example, they give way to the acid rain, which in turn generates collateral damage in the hydrosphere. Also, the production of oxide nitrous contributes to the greenhouse effect.
When using industrial fertilizers, all the remains end up in lakes, rivers and streams. In fact, fertilizer runoff produces eutrophication of salt and fresh water.
What is eutrophication?
The eutrophication is a phenomenon that reduces the amount of oxygen available in the water during the nights. This occurs because algae and other microorganisms that feed on organic molecules use oxygen in large quantities for cellular respiration.
Unfortunately, this phenomenon results in the death of other organisms that live in the marine ecosystems affected. Shrimp and fish are included, these being the most susceptible. Eventually, areas with oxygen levels so low that life would be completely ruled out are formed. They are called dead zones, where no type of species is housed.
What is the impact of the nitrogen cycle on ecosystems?
It is biogeochemical cycle of nitrogen it has a direct impact on all ecosystems. As we already mentioned, it affects both terrestrial life and ocean life. However, it is important to establish the type of effects it has based on human activity.
When the earth was created billions of years ago, the cycle of nitrogen contributed directly to its formation. Nowadays, it also fulfills a fundamental role for the conservation of life. However, industrial processes have caused a lot of damage and altered the