When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. 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 ...

  3. Reactive nitrogen - Wikipedia

    en.wikipedia.org/wiki/Reactive_nitrogen

    Reactive nitrogen ("Nr"), also known as fixed nitrogen [1], refers to all forms of nitrogen present in the environment except for molecular nitrogen (N 2 ). [ 2 ] While nitrogen is an essential element for life on Earth, molecular nitrogen is comparatively unreactive, and must be converted to other chemical forms via nitrogen fixation before it ...

  4. Nitrogen cycle - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_cycle

    Human activities have also dramatically altered the global nitrogen cycle by producing nitrogenous gases associated with global atmospheric nitrogen pollution. There are multiple sources of atmospheric reactive nitrogen (Nr) fluxes. Agricultural sources of reactive nitrogen can produce atmospheric emission of ammonia (NH 3), nitrogen oxides (NO

  5. Biological functions of nitric oxide - Wikipedia

    en.wikipedia.org/wiki/Biological_functions_of...

    Nitric oxide (nitrogen monoxide) is a molecule and chemical compound with chemical formula of N O. In mammals including humans, nitric oxide is a signaling molecule involved in several physiological and pathological processes. [1] It is a powerful vasodilator with a half-life of a few seconds in the blood.

  6. Pnictogen - Wikipedia

    en.wikipedia.org/wiki/Pnictogen

    Nitrogen is a component of molecules critical to life on earth, such as DNA and amino acids. Nitrates occur in some plants, due to bacteria present in the nodes of the plant. This is seen in leguminous plants such as peas [clarification needed] or spinach and lettuce. [citation needed] A typical 70 kg human contains 1.8 kg of nitrogen. [14]

  7. Nitrogen hypoxia to execute a human: 'Bloodless, but it won't ...

    www.aol.com/news/nitrogen-hypoxia-execute-human...

    Because no person has ever been executed by inhaling pure nitrogen, how the state will carry out a nitrogen hypoxia execution remains unclear. Nitrogen hypoxia to execute a human: 'Bloodless, but ...

  8. Free-radical theory of aging - Wikipedia

    en.wikipedia.org/wiki/Free-radical_theory_of_aging

    DNA cross-linking can in turn lead to various effects of aging, especially cancer. [21] Other cross-linking can occur between fat and protein molecules, which leads to wrinkles. [ 22 ] Free radicals can oxidize LDL , and this is a key event in the formation of plaque in arteries, leading to heart disease and stroke . [ 23 ]

  9. Nitrogen dioxide - Wikipedia

    en.wikipedia.org/wiki/Nitrogen_dioxide

    There, it chemically reacts with antioxidant and lipid molecules in the ELF. The health effects of NO 2 are caused by the reaction products or their metabolites, which are reactive nitrogen species and reactive oxygen species that can drive bronchoconstriction, inflammation, reduced immune response, and may have effects on the heart. [32]