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  2. Biological roles of the elements - Wikipedia

    en.wikipedia.org/wiki/Biological_roles_of_the...

    nitrogen: 7: 5: Ubiquitous, essential for all forms of life; all proteins and nucleic acids contain substantial amounts of nitrogen. [11] Toxic in some forms. [11] osmium: 76: 1a: None known. [11] Osmium is very rare, substantially more so than any element essential to life. [3] The oxide is toxic to humans. [11] oxygen: 8: 5

  3. Nitrogen fixation - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_fixation

    2.1 Importance of nitrogen. ... Nitrogen fixation is a chemical process ... Nitrogen fixation is essential to life on Earth because fixed inorganic nitrogen ...

  4. Nitrogen - Wikipedia

    en.wikipedia.org/wiki/Nitrogen

    [41] [42] Given the half-life difference, 13 N is the most important nitrogen radioisotope, being relatively long-lived enough to use in positron emission tomography (PET), although its half-life is still short and thus it must be produced at the venue of the PET, for example in a cyclotron via proton bombardment of 16 O producing 13 N and an ...

  5. Nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_cycle

    The nitrogen cycle is an important process in the ocean as well. While the overall cycle is similar, there are different players [40] and modes of transfer for nitrogen in the ocean. Nitrogen enters the water through the precipitation, runoff, or as N 2 from the atmosphere. Nitrogen cannot be utilized by phytoplankton as N

  6. Human impact on the nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Human_impact_on_the...

    Approximately 78% of Earth's atmosphere is N gas (N 2), which is an inert compound and biologically unavailable to most organisms.In order to be utilized in most biological processes, N 2 must be converted to reactive nitrogen (Nr), which includes inorganic reduced forms (NH 3 and NH 4 +), inorganic oxidized forms (NO, NO 2, HNO 3, N 2 O, and NO 3 −), and organic compounds (urea, amines, and ...

  7. Discovering how to make 'synthetic nitrogen' became life's ...

    www.aol.com/news/discovering-synthetic-nitrogen...

    Carbon, nitrogen, and oxygen. None is more important than the other but if there's a first among equals it would be nitrogen. Discovering how to make 'synthetic nitrogen' became life's massive ...

  8. Plant nutrition - Wikipedia

    en.wikipedia.org/wiki/Plant_nutrition

    Therefore, nitrogen is often the limiting factor for growth and biomass production in all environments where there is a suitable climate and availability of water to support life. Microorganisms have a central role in almost all aspects of nitrogen availability, and therefore for life support on earth.

  9. Nitrogen balance - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_balance

    Nitrogen is a fundamental chemical component of amino acids, the molecular building blocks of protein. As such, nitrogen balance may be used as an index of protein metabolism. [1] When more nitrogen is gained than lost by an individual, they are considered to have a positive nitrogen balance and be in a state of overall protein anabolism.