enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Oxygen cycle - Wikipedia

    en.wikipedia.org/wiki/Oxygen_cycle

    The word oxygen in the literature typically refers to the most common oxygen allotrope, elemental/diatomic oxygen (O 2), as it is a common product or reactant of many biogeochemical redox reactions within the cycle. [2] Processes within the oxygen cycle are considered to be biological or geological and are evaluated as either a source (O 2 ...

  3. Photorespiration - Wikipedia

    en.wikipedia.org/wiki/Photorespiration

    This oxaloacetate is then converted to malate and is transported into the bundle sheath cells (site of carbon dioxide fixation by RuBisCO) where oxygen concentration is low to avoid photorespiration. Here, carbon dioxide is removed from the malate and combined with RuBP by RuBisCO in the usual way, and the Calvin cycle proceeds as

  4. Ecosystem respiration - Wikipedia

    en.wikipedia.org/wiki/Ecosystem_respiration

    This constant cycle of carbon through the system is not the only element being transferred. In animal and plant respiration these living beings take in glucose and oxygen while emitting energy, carbon dioxide, and water as waste. These constant cycles provide for a influx of oxygen into the system and carbon out of the system.

  5. Great Oxidation Event - Wikipedia

    en.wikipedia.org/wiki/Great_Oxidation_Event

    Oxygen likely oxidized atmospheric methane (a strong greenhouse gas) to carbon dioxide (a weaker one) and water. This weakened the greenhouse effect of the Earth's atmosphere, causing planetary cooling, which has been proposed to have triggered a series of ice ages known as the Huronian glaciation , bracketing an age range of 2.45–2.22 Ga ...

  6. Dioxygen in biological reactions - Wikipedia

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

    Monooxygenase uses oxygen for many oxidation reactions in the body. Oxygen that is suspended in the blood plasma equalizes into the tissue according to Henry's law. Carbon dioxide, a waste product, is released from the cells and into the blood, where it is converted to bicarbonate or binds to hemoglobin for transport to the lungs.

  7. Oxygen - Wikipedia

    en.wikipedia.org/wiki/Oxygen

    Paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in the shells and skeletons of marine organisms to determine the climate millions of years ago (see oxygen isotope ratio cycle). Seawater molecules that contain the lighter isotope , oxygen-16, evaporate at a slightly faster rate than water molecules containing the 12% heavier ...

  8. Biogeochemical cycle - Wikipedia

    en.wikipedia.org/wiki/Biogeochemical_cycle

    A biogeochemical cycle, or more generally a cycle of matter, [1] is the movement and transformation of chemical elements and compounds between living organisms, the atmosphere, and the Earth's crust. Major biogeochemical cycles include the carbon cycle, the nitrogen cycle and the water cycle. In each cycle, the chemical element or molecule is ...

  9. Bicarbonate indicator - Wikipedia

    en.wikipedia.org/wiki/Bicarbonate_indicator

    The indicator is used in photosynthesis and respiration experiments to find out whether carbon dioxide is being liberated. [1] It is also used to test the carbon dioxide content during gaseous exchange of organisms. When the carbon dioxide content is higher than 0.04%, the initial red colour changes to yellow as the pH becomes more acidic.