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Hydrogenation is a chemical reaction between molecular hydrogen (H 2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically constitutes the addition of pairs of hydrogen atoms to a molecule ...
It occurs in 16,000 species (about 7% of plants), belonging to over 300 genera and around 40 families, but this is thought to be a considerable underestimate. [24] The great majority of plants using CAM are angiosperms (flowering plants) but it is found in ferns , Gnetopsida and in quillworts (relatives of club mosses ).
Chemiosmosis is the movement of ions across a semipermeable membrane bound structure, down their electrochemical gradient.An important example is the formation of adenosine triphosphate (ATP) by the movement of hydrogen ions (H +) across a membrane during cellular respiration or photosynthesis.
The Calvin cycle is present in all photosynthetic eukaryotes and also many photosynthetic bacteria. In plants, these reactions occur in the stroma, the fluid-filled region of a chloroplast outside the thylakoid membranes. These reactions take the products (ATP and NADPH) of light-dependent reactions and perform further chemical processes on them.
The latter occurs not only in plants but also in animals when the carbon and energy from plants is passed through a food chain. The fixation or reduction of carbon dioxide is a process in which carbon dioxide combines with a five-carbon sugar , ribulose 1,5-bisphosphate , to yield two molecules of a three-carbon compound, glycerate 3-phosphate ...
Plant hormones, which are secondary metabolites, are often used to regulate the metabolic activity within cells and oversee the overall development of the plant. As mentioned above in the History tab, secondary plant metabolites help the plant maintain an intricate balance with the environment, often adapting to match the environmental needs.
Hydrogenation is used to convert unsaturated fats and oils to saturated (trans) fats and oils. The major application is the production of margarine. Methanol is produced by hydrogenation of carbon dioxide. It is similarly the source of hydrogen in the manufacture of hydrochloric acid.
The hydrogenation of a methenyl-H4MPT+ occurs instead of H 2 oxidation/production, which is the case for the other two types of hydrogenases. While the exact mechanism of the catalysis is still under study, recent finding suggests that molecular hydrogen is first heterolytically cleaved by Fe(II), followed by transfer of hydride to the ...