When they consume an adequate amount of protein by eating a healthy animal, their body will experience something called a positive balance of nitrogen. Nitrogen is very much necessary for making the various biomolecules we need in our body. We know that proteins are the building blocks of life. Proteins are present in hormones, cell signaling pathways, hair, muscles, skin, and almost everywhere we can imagine in the animal body.
And also, all animal tissue — muscles, skin, hair, nails, and blood — contains protein as already said above. So, the normal growth, cell signaling, body working, cell replacement, and tissue repair, etc, all require nitrogen. So, Can life survive without nitrogen? Nitrogen cycle is the repeating cycle of the flow of nitrogen from the biotic components to the abiotic components and back to the biotic components constantly in the ecosystem.
The biotic components include air atmosphere , water hydrosphere , and soil lithosphere. While the abiotic components include plants and animals. The atmospheric nitrogen is fixed by the nitrogen-fixing bacteria into the soil. The nitrogen can also enter from soil to the water bodies due to the surface runoff of the excess chemicals into the water bodies which can also harm the water quality. So, the nitrogen in the water bodies will be taken by the aquatic plants due to the various nitrogen-fixing bacteria present inside water.
Now, the plants will be consumed by the animals and so the nitrogen will next pass into the animal body. Now when the animals die the nitrogen will go back to the soil and then the various denitrifying bacteria will release it back to the atmosphere or hydrosphere. And, this repeating flow of nitrogen is better known as the nitrogen cycle. So, What does the nitrogen cycle do for animals? As the nitrogen enters the animal body it will find its way from food towards the various cells where it will be utilized in the formation of proteins, and nucleic acids, and other necessary biomolecules.
These nitrogen-containing biomolecules will form hair, body tissues, fur, skin, cell organelles, muscles, bones, etc. Living animals return nitrogen to the environment when they urinate or excrete their feces in the soil. Animals can also return nitrogen in their body to the environment when they die and then the decomposers in the soil starts to decompose the dead body. This is important because plants can assimilate nitrate into their tissues, and they rely on bacteria to convert it from ammonia to a usable form.
Nitrification is performed mainly by the genus of bacteria, Nitrobacter. Nitrification can also work on ammonium. It can either be cycled back into a plant usable form through nitrification or returned to the atmosphere through de-nitrification. De-Nitrification: Nitrogen in its nitrate form NO 3 — is converted back into atmospheric nitrogen gas N 2 by bacterial species such as Pseudomonas and Clostridium, usually in anaerobic conditions. These bacteria use nitrate as an electron acceptor instead of oxygen during respiration.
Learning Objectives Describe the nitrogen cycle and how it is affected by human activity. Key Points Nitrogen is converted from atmospheric nitrogen N2 into usable forms, such as NO2-, in a process known as fixation.
The majority of nitrogen is fixed by bacteria, most of which are symbiotic with plants. They receive their nutrient supplies by consuming plants or plant-consuming animals. When nitrogen nutrients have served their purpose in plants and animals, specialized decomposing bacteria will start a process called ammonification , to convert them back into ammonia and water-soluble ammonium salts.
After the nutrients are converted back into ammonia, anaerobic bacteria will convert them back into nitrogen gas, during a process called denitrification. The whole process starts over after release. A schematic representation of the nitrogen cycle is shown here: Nitrogen as a limiting factor Although the nitrogen conversion processes often occurs and large quantities of plant nutrients are produced, nitrogen is often a limiting factor for plant growth. Water flowing across the soil causes this error.
Nitrogen nutrients are water-soluble and as a result they are easily drained away, so that they are no longer available for plants. The annamox reaction In researchers at the Gist-Brocades in Delft, The Netherlands, discovered a new reaction to be added to the nitrogen cycle; the so-called annamox reaction.
This is now found to occur in the Black Sea, as well.
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