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  2. Ecosystem respiration - Wikipedia

    en.wikipedia.org/wiki/Ecosystem_respiration

    Ecosystem respiration is typically measured in the natural environment, such as a forest or grassland, rather than in the laboratory. Ecosystem respiration is the production portion of carbon dioxide in an ecosystem's carbon flux , while photosynthesis typically accounts for the majority of the ecosystem's carbon consumption. [ 3 ]

  3. Photosynthetic efficiency - Wikipedia

    en.wikipedia.org/wiki/Photosynthetic_efficiency

    The following is a breakdown of the energetics of the photosynthesis process from Photosynthesis by Hall and Rao: [6]. Starting with the solar spectrum falling on a leaf, 47% lost due to photons outside the 400–700 nm active range (chlorophyll uses photons between 400 and 700 nm, extracting the energy of one 700 nm photon from each one)

  4. Fractionation of carbon isotopes in oxygenic photosynthesis

    en.wikipedia.org/wiki/Fractionation_of_carbon...

    δ 13 C sample is the delta-value of the organism for 13 C composition; δ 13 C atm is the delta-value of atmospheric CO 2, which is = -7.8‰ the discrimination due to diffusion a = 4.4‰ the carboxylation discrimination b = 30‰ c a is the partial pressure of CO 2 in the external atmosphere, and; c i is the partial pressure of CO 2 in the ...

  5. Photorespiration - Wikipedia

    en.wikipedia.org/wiki/Photorespiration

    C 2 photosynthesis (also called glycine shuttle and photorespiratory CO 2 pump) is a CCM that works by making use of – as opposed to avoiding – photorespiration. It performs carbon refixation by delaying the breakdown of photorespired glycine, so that the molecule is shuttled from the mesophyll into the bundle sheath .

  6. Photosystem II - Wikipedia

    en.wikipedia.org/wiki/Photosystem_II

    Currently structures of the S1 state and the S3 state's have been published almost simultaneously from two different groups, showing the addition of an oxygen molecule designated O6 between Mn1 and Mn4, [13] [14] suggesting that this may be the site on the oxygen evolving complex, where oxygen is produced.

  7. Isotopes of oxygen - Wikipedia

    en.wikipedia.org/wiki/Isotopes_of_oxygen

    Oxygen-15 is a radioisotope, often used in positron emission tomography (PET). It can be used in, among other things, water for PET myocardial perfusion imaging and for brain imaging. [ 20 ] [ 21 ] It has an atomic mass of 15.003 0656 (5) , and a half-life of 122.266(43) s .

  8. Photosynthesis system - Wikipedia

    en.wikipedia.org/wiki/Photosynthesis_System

    Photosynthesis systems function by measuring gas exchange of leaves. Atmospheric carbon dioxide is taken up by leaves in the process of photosynthesis, where CO 2 is used to generate sugars in a molecular pathway known as the Calvin cycle. This draw-down of CO 2 induces more atmospheric CO 2 to diffuse through stomata into the air spaces of the ...

  9. Porphyrin - Wikipedia

    en.wikipedia.org/wiki/Porphyrin

    In vertebrates, an essential member of the porphyrin group is heme, which is a component of hemoproteins, whose functions include carrying oxygen in the bloodstream. In plants , an essential porphyrin derivative is chlorophyll , which is involved in light harvesting and electron transfer in photosynthesis .