Examples of nitrogen fixation in the following topics:
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- Abiotic nitrogen fixation occurs as a result of lightning or by industrial processes.
- Biological nitrogen fixation (BNF) is exclusively carried out by prokaryotes: soil bacteria, cyanobacteria, and Frankia spp.
- Nitrogenase, the enzyme that fixes nitrogen, is inactivated by oxygen, so the nodule provides an oxygen-free area for nitrogen fixation to take place.
- Through symbiotic nitrogen fixation, the plant benefits from using an endless source of nitrogen: the atmosphere.
- Explain the need for nitrogen fixation and how it is accomplished
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- Biological nitrogen fixation (BNF), the conversion of atmospheric nitrogen (N2) into ammonia (NH3), is exclusively carried out by prokaryotes, such as soil bacteria or cyanobacteria.
- The NH3 resulting from fixation can be transported into plant tissue and incorporated into amino acids, which are then made into plant proteins.
- Soil bacteria, collectively called rhizobia, symbiotically interact with legume roots to form specialized structures called nodules in which nitrogen fixation takes place .
- Through symbiotic nitrogen fixation, the plant benefits from using an endless source of nitrogen from the atmosphere.
- Abiotic nitrogen fixation has been omitted.
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- Nitrogen is cycled through the earth via the multi-step process of nitrogen fixation, which is carried out by bacteria.
- Nitrogen enters the living world via free-living and symbiotic bacteria, which incorporate nitrogen into their macromolecules through nitrogen fixation (conversion of N2).
- Cyanobacteria live in most aquatic ecosystems where sunlight is present; they play a key role in nitrogen fixation.
- Cyanobacteria are able to use inorganic sources of nitrogen to "fix" nitrogen.
- The nitrogen that enters living systems by nitrogen fixation is successively converted from organic nitrogen back into nitrogen gas by bacteria .
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- Prokaryotes play vital roles in the movement of carbon dioxide and nitrogen in the carbon and nitrogen cycles.
- Nitrogen is a very important element for life because it is part of proteins and nucleic acids.
- As a macronutrient in nature, it is recycled from organic compounds to ammonia, ammonium ions, nitrate, nitrite, and nitrogen gas by myriad processes, many of which are carried out solely by prokaryotes; they are key to the nitrogen cycle .
- The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen from the air, but this nitrogen is not usable by plants, which are primary producers.
- Gaseous nitrogen is transformed, or "fixed," into more-readily available forms such as ammonia through the process of nitrogen fixation by natural means, especially by microorganisms (prokayotes) in the soil.
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- About half of the essential elements are considered macronutrients: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
- The next-most-abundant element in plant cells is nitrogen (N); it is part of proteins and nucleic acids.
- Nitrogen is also used in the synthesis of some vitamins.
- Some plants use it for nitrogen fixation; thus, it may need to be added to some soils before seeding legumes.
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- Its biosynthesis involves breaking the triple bond of molecular nitrogen, or N2, followed by the formation of several carbon-nitrogen single and double bonds.
- The strength of different levels of covalent bonding is one of the main reasons living organisms have a difficult time in acquiring nitrogen for use in constructing nitrogenous molecules, even though molecular nitrogen, N2, is the most abundant gas in the atmosphere.
- Molecular nitrogen consists of two nitrogen atoms triple bonded to each other.
- The resulting strong triple bond makes it difficult for living systems to break apart this nitrogen in order to use it as constituents of biomolecules, such as proteins, DNA, and RNA.
- Its biosynthesis involves the fixation of nitrogen to provide feedstocks that eventually produce the carbon-nitrogen bonds it contains.
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- Some plants such as cacti can prepare materials for photosynthesis during the night by a temporary carbon fixation and storage process, because opening the stomata at this time conserves water due to cooler temperatures.
- In contrast to C4 metabolism, which physically separates the CO2 fixation to PEP from the Calvin cycle, CAM temporally separates these two processes.
- Decarboxylation of malate during the day releases CO2 inside the leaves, thus allowing carbon fixation to 3-phosphoglycerate by RuBisCO.
- Due to the inactivity required by the CAM mechanism, C4 carbon fixation has a greater efficiency in terms of PGA synthesis.
- Over 90% of plants use C3 carbon fixation, compared to 3% that use C4 carbon fixation; however, the evolution of C4 in over 60 plant lineages makes it a striking example of convergent evolution.
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- Because they secrete urea as the primary nitrogenous waste product, they are called ureotelic animals.
- Urea serves an important role in the metabolism of nitrogen-containing compounds by animals.
- It is the main nitrogen-containing substance in the urine of mammals.
- The body uses it in many processes, the most notable one being nitrogen excretion.
- Urea is widely used in fertilizers as a convenient source of nitrogen.
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- Of the four major macromolecules in biological systems, both proteins and nucleic acids contain nitrogen.
- Excess nitrogen is excreted from the body.
- Nitrogenous wastes tend to form toxic ammonia, which raises the pH of body fluids.
- It contains four nitrogen atoms; only a small amount of water is needed for its excretion.
- Nitrogenous waste is excreted in different forms by different species.
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- The Calvin cycle is organized into three basic stages: fixation, reduction, and regeneration.
- The light-independent reactions of the Calvin cycle can be organized into three basic stages: fixation, reduction, and regeneration.
- This process is called carbon fixation because CO2 is "fixed" from an inorganic form into organic molecules.