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  2. Zinc in biology - Wikipedia

    en.wikipedia.org/wiki/Zinc_in_biology

    Zinc fingers help read DNA sequences.. Zinc is an essential trace element for humans [1] [2] [3] and other animals, [4] for plants [5] and for microorganisms. [6] Zinc is required for the function of over 300 enzymes and 1000 transcription factors, [3] and is stored and transferred in metallothioneins.

  3. Water cycle - Wikipedia

    en.wikipedia.org/wiki/Water_cycle

    The diagram also shows how human water use impacts where water is stored and how it moves. [1] The water cycle (or hydrologic cycle or hydrological cycle) is a biogeochemical cycle that involves the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time.

  4. Light-dependent reactions - Wikipedia

    en.wikipedia.org/wiki/Light-dependent_reactions

    Light-dependent reactions of photosynthesis at the thylakoid membrane. Light-dependent reactions are certain photochemical reactions involved in photosynthesis, the main process by which plants acquire energy. There are two light dependent reactions: the first occurs at photosystem II (PSII) and the second occurs at photosystem I (PSI).

  5. Photosystem II - Wikipedia

    en.wikipedia.org/wiki/Photosystem_II

    Photosynthetic water splitting (or oxygen evolution) is one of the most important reactions on the planet, since it is the source of nearly all the atmosphere's oxygen. Moreover, artificial photosynthetic water-splitting may contribute to the effective use of sunlight as an alternative energy-source.

  6. Zinc cycle - Wikipedia

    en.wikipedia.org/wiki/Zinc_cycle

    Zinc fluxes between the lithosphere and biosphere, through basins in soil, biomass, water systems, and industry. [1] Estimated fluxes are shown as labeled arrows in Gg/year. The zinc cycle is a biogeochemical cycle that transports zinc through the lithosphere, hydrosphere, and biosphere.

  7. Fractionation of carbon isotopes in oxygenic photosynthesis

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

    In contrast, C3 plants directly perform the Calvin Cycle in mesophyll cells, without making use of a CO 2 concentration method. Malate, the four-carbon compound is the namesake of "C4" photosynthesis. This pathway allows C4 photosynthesis to efficiently shuttle CO 2 to the RuBisCO enzyme and maintain high concentrations of CO 2 within bundle ...

  8. Photoautotroph - Wikipedia

    en.wikipedia.org/wiki/Photoautotroph

    Cyanobacteria is the only prokaryotic group that performs oxygenic photosynthesis. Anoxygenic photosynthetic bacteria use PSI- and PSII-like photosystems, which are pigment protein complexes for capturing light. [5] Both of these photosystems use bacteriochlorophyll. There are multiple hypotheses for how oxygenic photosynthesis evolved.

  9. Marine biogeochemical cycles - Wikipedia

    en.wikipedia.org/wiki/Marine_biogeochemical_cycles

    Water is the medium of the oceans, the medium which carries all the substances and elements involved in the marine biogeochemical cycles. Water as found in nature almost always includes dissolved substances, so water has been described as the "universal solvent" for its ability to dissolve so many substances.