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  2. Biological thermodynamics - Wikipedia

    en.wikipedia.org/wiki/Biological_thermodynamics

    In animals, the processes of alternating cycles of biochemical reactions of ATP synthesis and cleavage occur automatically. Moreover, the processes of alternating cycles of biochemical reactions at the levels of organs, systems and the whole organism, for example, respiration , heart contractions and others occur with different periods and ...

  3. 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 ...

  4. Metabolic pathway - Wikipedia

    en.wikipedia.org/wiki/Metabolic_pathway

    In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell.The reactants, products, and intermediates of an enzymatic reaction are known as metabolites, which are modified by a sequence of chemical reactions catalyzed by enzymes.

  5. Transmethylation - Wikipedia

    en.wikipedia.org/wiki/Transmethylation

    Transmethylation is a biologically important organic chemical reaction in which a methyl group is transferred from one compound to another. An example of transmethylation is the recovery of methionine from homocysteine. In order to sustain sufficient reaction rates during metabolic stress, this reaction requires adequate levels of vitamin B 12 ...

  6. Urea cycle - Wikipedia

    en.wikipedia.org/wiki/Urea_cycle

    The urea cycle (also known as the ornithine cycle) is a cycle of biochemical reactions that produces urea (NH 2) 2 CO from ammonia (NH 3). Animals that use this cycle, mainly amphibians and mammals, are called ureotelic. The urea cycle converts highly toxic ammonia to urea for excretion. [1]

  7. Iron-oxidizing bacteria - Wikipedia

    en.wikipedia.org/wiki/Iron-oxidizing_bacteria

    The anoxygenic phototrophic iron oxidation was the first anaerobic metabolism to be described within the iron anaerobic oxidation metabolism. The photoferrotrophic bacteria use Fe 2+ as electron donor and the energy from light to assimilate CO 2 into biomass through the Calvin Benson-Bassam cycle (or rTCA cycle) in a neutrophilic environment (pH 5.5-7.2), producing Fe 3+ oxides as a waste ...

  8. Table of standard reduction potentials for half-reactions ...

    en.wikipedia.org/wiki/Table_of_standard...

    The values below are standard apparent reduction potentials (E°') for electro-biochemical half-reactions measured at 25 °C, 1 atmosphere and a pH of 7 in aqueous solution. [1] [2] The actual physiological potential depends on the ratio of the reduced (Red) and oxidized (Ox) forms according to the Nernst equation and the thermal voltage.

  9. Photorespiration - Wikipedia

    en.wikipedia.org/wiki/Photorespiration

    Photorespiration involves a complex network of enzyme reactions that exchange metabolites between chloroplasts, leaf peroxisomes and mitochondria. The oxygenation reaction of RuBisCO is a wasteful process because 3-phosphoglycerate is created at a lower rate and higher metabolic cost compared with RuBP carboxylase activity.