When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    The appearance of highly reactive free oxygen, which can oxidize organic compounds (especially genetic materials) and thus is toxic to the then-mostly anaerobic biosphere, may have caused the extinction/extirpation of many early organisms on Earth – mostly archaeal colonies that used retinal to use green-spectrum light energy and power a form ...

  3. Geological history of oxygen - Wikipedia

    en.wikipedia.org/wiki/Geological_history_of_oxygen

    The increase in oxygen concentrations had wide ranging and significant impacts on Earth's biosphere. Most significantly, the rise of oxygen and the oxidative depletion of greenhouse gases (especially atmospheric methane ) due to the GOE led to an icehouse Earth that caused a mass extinction of anaerobic microbes , but paved the way for the ...

  4. Oxygen evolution - Wikipedia

    en.wikipedia.org/wiki/Oxygen_evolution

    Photosynthetic oxygen evolution is the fundamental process by which oxygen is generated in the earth's biosphere. The reaction is part of the light-dependent reactions of photosynthesis in cyanobacteria and the chloroplasts of green algae and plants. It utilizes the energy of light to split a water molecule into its protons and electrons for ...

  5. Dioxygen in biological reactions - Wikipedia

    en.wikipedia.org/wiki/Dioxygen_in_biological...

    Free oxygen is produced in the biosphere through photolysis (light-driven oxidation and splitting) of water during photosynthesis in cyanobacteria, green algae, and plants. During oxidative phosphorylation in cellular respiration , oxygen is reduced to water, thus closing the biological water-oxygen redox cycle.

  6. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    In nature, singlet oxygen is commonly formed from water during photosynthesis, using the energy of sunlight. [38] It is also produced in the troposphere by the photolysis of ozone by light of short wavelength [ 39 ] and by the immune system as a source of active oxygen. [ 40 ]

  7. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    The flow of energy in an ecosystem is an open system; the Sun constantly gives the planet energy in the form of light while it is eventually used and lost in the form of heat throughout the trophic levels of a food web. Carbon is used to make carbohydrates, fats, and proteins, the major sources of food energy. These compounds are oxidized to ...

  8. A New Kind of Battery—Oxygen-Ion—Could Change Energy - AOL

    www.aol.com/lifestyle/kind-battery-oxygen-ion...

    It’s incredibly rechargeable, made from safe materials, and—get this—not going to catch on fire.

  9. Aerobic organism - Wikipedia

    en.wikipedia.org/wiki/Aerobic_organism

    Facultative anaerobes use oxygen if it is available, but also have anaerobic methods of energy production. [7] Microaerophiles require oxygen for energy production, but are harmed by atmospheric concentrations of oxygen (21% O 2). [6] Aerotolerant anaerobes do not use oxygen but are not harmed by it. [6]