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NAD + to NADH. FMN to FMNH 2. CoQ to CoQH 2.. Complex I is the first enzyme of the mitochondrial electron transport chain.There are three energy-transducing enzymes in the electron transport chain - NADH:ubiquinone oxidoreductase (complex I), Coenzyme Q – cytochrome c reductase (complex III), and cytochrome c oxidase (complex IV). [1]
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.
In eukaryotes, NADH is the most important electron donor. The associated electron transport chain is NADH → Complex I → Q → Complex III → cytochrome c → Complex IV → O 2 where Complexes I, III and IV are proton pumps, while Q and cytochrome c are mobile electron carriers. The electron acceptor for this process is molecular oxygen.
NADPH oxidase (nicotinamide adenine dinucleotide phosphate oxidase) is a membrane-bound enzyme complex that faces the extracellular space. It can be found in the plasma membrane as well as in the membranes of phagosomes used by neutrophil white blood cells to engulf microorganisms.
Including one H + for the transport reactions, this means that synthesis of one ATP requires 1 + 10/3 = 4.33 protons in yeast and 1 + 8/3 = 3.67 in vertebrates. This would imply that in human mitochondria the 10 protons from oxidizing NADH would produce 2.72 ATP (instead of 2.5) and the 6 protons from oxidizing succinate or ubiquinol would ...
Following glycolysis, the citric acid cycle is activated by the production of acetyl-CoA. The oxidation of pyruvate by pyruvate dehydrogenase in the matrix produces CO 2, acetyl-CoA, and NADH. Beta oxidation of fatty acids serves as an alternate catabolic pathway that produces acetyl-CoA, NADH, and FADH 2. [1]
In enzymology, a NADH peroxidase (EC 1.11.1.1) is an enzyme that catalyzes the chemical reaction. NADH + H + + H 2 O 2 NAD + + 2 H 2 O. The presumed function of NADH peroxidase is to inactivate H 2 O 2 generated within the cell, for example by glycerol-3-phosphate oxidase during glycerol metabolism or dismutation of superoxide, before the H 2 O 2 causes damage to essential cellular components.
The effects of the NAD + /NADH ratio are complex, controlling the activity of several key enzymes, including glyceraldehyde 3-phosphate dehydrogenase and pyruvate dehydrogenase. In healthy mammalian tissues, estimates of the ratio of free NAD + to NADH in the cytoplasm typically lie around 700:1; the ratio is thus favorable for oxidative reactions.