chemiosmotic theory
chemiosmotic theory A theory postulated by the British biochemist Peter Mitchell (1920–92) to explain the formation of ATP in the mitochondrial electron transport chain. As electrons are transferred along the electron carrier system in the inner mitochondrial membrane, hydrogen ions (protons) are actively transported (by proton pumps) into the space between the inner and outer mitochondrial membranes, which thus contains a higher concentration of protons than the matrix. This creates an electrochemical gradient across the inner membrane, down which protons move back into the matrix. This movement occurs through special channels associated with ATP synthetase, the enzyme that catalyses the conversion of ADP to ATP, and is coupled with the phosphorylation of ADP (see illustration). A similar gradient is created across the thylakoid membranes of chloroplasts during the light-dependent reactions of photosynthesis (see photophosphorylation).
chemiosmotic theory
chemiosmotic theory A theory concerning oxidative phosphorylation in which it is proposed that the electron-transport chain is arranged such that it generates an energy-rich proton gradient across the inner membrane of a mitochondrion, and electrons cross the membrane by a mechanism reminiscent of that in which molecules of solvent cross a semi-permeable membrane in osmosis. The energy is then used to drive the phosphorylation of ADP through a membrane-bound ATP-ase.
chemiosmotic theory
chemiosmotic theory A theory concerning oxidative phosphorylation in which it is proposed that the electron-transport chain is arranged such that it generates an energy-rich proton gradient across the inner membrane of a mitochondrion. This energy is then used to drive the phosphorylation of ADP through a membrane-bound ATP-ase.
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Photophosphorylation , photophosphorylation The formation of ATP from ADP and inorganic phosphate using light energy in photosynthesis (compare oxidative phosphorylation).… Cytochrome , Cytochromes are electron-transporting protein pigments concerned with cell respiration that contain an iron-containing molecule called heme, allied t… Oxidative Phosphorylation , Glycolysis and the Krebs cycle both generate the high-energy compound adenosine triphosphate (ATP ) directly, by substrate -level phosphorylation, bu… Hendrik Antoon Lorentz , Lorentz, Hendrik Antoon
Lorentz, Hendrik Antoon
theoretical physics.
Lorentz, father, Gerrit Frederik Lorentz, owned a nursery near Arnhem. His mothe… Mitochondria , Mitochondria are organelles found in the cytoplasm of all eukaryotic cells. They vary considerably in shape and size, but are all composed of four co… Phosphorylation , phosphorylation, chemical process in which a phosphate group is added to an organic molecule. In living cells phosphorylation is associated with resp…
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