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The generation of ATP by chemiosmosis occurs in mitochondria and chloroplasts, as well as in most bacteria and archaea. For instance, in chloroplasts during photosynthesis, an electron transport chain pumps H + ions (protons) in the stroma (fluid) through the thylakoid membrane to the thylakoid spaces.
Oxidative phosphorylation is made up of two closely connected components: the electron transport chain and chemiosmosis. The electron transport chain in the cell is the site of oxidative phosphorylation. The NADH and succinate generated in the citric acid cycle are oxidized, releasing the energy of O 2 to power the ATP synthase.
This transport chain produces a proton-motive force, pumping H + ions across the membrane and producing a concentration gradient that can be used to power ATP synthase during chemiosmosis. This pathway is known as cyclic photophosphorylation, and it produces neither O 2 nor NADPH.
Simplified structure of a mitochondrion. The intermembrane space (IMS) is the space occurring between or involving two or more membranes. [1] In cell biology, it is most commonly described as the region between the inner membrane and the outer membrane of a mitochondrion or a chloroplast.
In biology, electrochemical gradients allow cells to control the direction ions move across membranes. In mitochondria and chloroplasts, proton gradients generate a chemiosmotic potential used to synthesize ATP, [1] and the sodium-potassium gradient helps neural synapses quickly transmit information. [citation needed]
The post-glycolytic reactions take place in the mitochondria in eukaryotic cells, and in the cytoplasm in prokaryotic cells. [citation needed] Although plants are net consumers of carbon dioxide and producers of oxygen via photosynthesis, plant respiration accounts for about half of the CO 2 generated annually by terrestrial ecosystems. [6] [7]: 87
The structure and function of cytochrome b 6 f (in chloroplasts) is very similar to cytochrome bc 1 (Complex III in mitochondria). Both are transmembrane structures that remove electrons from a mobile, lipid-soluble electron carrier (plastoquinone in chloroplasts; ubiquinone in mitochondria) and transfer them to a mobile, water-soluble electron ...
In bacteria and ATP-producing organelles other than mitochondria, reducing equivalents provided by electron transfer or photosynthesis power the translocation of protons. [citation needed] CF 1 ATP ligase of chloroplasts correspond to the human F O F 1 ATP synthase in plants. [citation needed]