Electron-transfer-chain catalysis

We next focus on the use of fixed-site cofactors and coenzymes. We note that much of this coenzyme chemistry is now linked to very local two-electron chemistry (H, CH3", CH3CO-, -NH2,0 transfer) in enzymes. Additionally, one-electron changes of coenzymes, quinones, flavins and metal ions especially in membranes are used very much in very fast intermediates of twice the one-electron switches over considerable electron transfer distances. At certain points, the chains of catalysis revert to a two-electron reaction (see Figure 5.2), and the whole complex linkage of diffusion and carriers is part of energy transduction (see also proton transfer and Williams in Further Reading). There is a variety of additional coenzymes which are fixed and which we believe came later in evolution, and there are the very important metal ion cofactors which are separately considered below. 

A major part of the attractivity of SET reactions is related to the possibility of electron transfer catalysis, e.g. within chain processes related to the Srn2 mechanism. The wide scope of this kind or reactivity has been pointed out especially by Chanon [11,143]. 

Electrocatalysis, also named Electron-Transfer-Chain (ETC) catalysis, whereby a reaction (mostly of non-redox type) is catalyzed by an electron (reduction) or by an electron hole (oxidation). Organotransition-metal complexes can carry an electron or an electron hole and, if they achieve this function without decomposition, they are electron-reservoir complexes [6],... 

Here, we have only emphasized types of dendrimer catalysis involving electron transfer (redox catalysis and electron transfer chain (ETC) catalysis). Other types of dendrimer catalysis are reviewed elsewhere.6,7... 

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