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When working at the frontier between inorganic and biological processes (e.g., when comparing abiotic and biotic processes in geochemistry when microbial activity could also be at work in the system), care must be taken not to inadvertently directly mix standard reduction potentials (versus SHE, pH = 0) with formal (or apparent) reduction ...
The term redox state is often used to describe the balance of GSH/GSSG, NAD + /NADH and NADP + /NADPH in a biological system such as a cell or organ. The redox state is reflected in the balance of several sets of metabolites (e.g., lactate and pyruvate , beta-hydroxybutyrate and acetoacetate ), whose interconversion is dependent on these ratios.
In this way, ferredoxin acts as an electron transfer agent in biological redox reactions. Other bioinorganic electron transport systems include rubredoxins, cytochromes, blue copper proteins, and the structurally related Rieske proteins. Ferredoxins can be classified according to the nature of their iron–sulfur clusters and by sequence ...
In aqueous solutions, redox potential is a measure of the tendency of the solution to either gain or lose electrons in a reaction. A solution with a higher (more positive) reduction potential than some other molecule will have a tendency to gain electrons from this molecule (i.e. to be reduced by oxidizing this other molecule) and a solution with a lower (more negative) reduction potential ...
In electrochemistry, the Nernst equation is a chemical thermodynamical relationship that permits the calculation of the reduction potential of a reaction (half-cell or full cell reaction) from the standard electrode potential, absolute temperature, the number of electrons involved in the redox reaction, and activities (often approximated by concentrations) of the chemical species undergoing ...
Another source of ROS production in animal cells is the electron transfer reactions catalyzed by the mitochondrial P450 systems in steroidogenic tissues. [24] These P450 systems are dependent on the transfer of electrons from NADPH to P450. During this process, some electrons "leak" and react with O 2 producing superoxide.
For example, an enzyme that catalyzed this reaction would be an oxidoreductase: A – + B → A + B – In this example, A is the reductant (electron donor) and B is the oxidant (electron acceptor). In biochemical reactions, the redox reactions are sometimes more difficult to see, such as this reaction from glycolysis:
An electron transport chain (ETC [1]) is a series of protein complexes and other molecules which transfer electrons from electron donors to electron acceptors via redox reactions (both reduction and oxidation occurring simultaneously) and couples this electron transfer with the transfer of protons (H + ions) across a membrane.