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Tag: Redirect target changed |
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| The term '''electron transfer chain''' (or electron transport chain, ETC) is a misnomer. Understanding mitochondrial respiratory control has suffered greatly from this inappropriate terminology, although textbooks using the term ETC (Lehninger 1970; Nicholls & Ferguson 2002) make it sufficiently clear that '''electron transfer systems are not arranged as a chain''': the „ETC‟ is in fact not a simple chain but '''an arrangement of electron transfer complexes in a non-linear, convergent electron transfer system''' (Hatefi et al 1962; ETS).
| | #REDIRECT [[Electron transfer pathway]] |
| The firmly established convention of defining the electron transfer chain as being comprised of four Complexes has conceptual weaknesses.
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| (a) In fact, there are at least six Complexes of mitochondrial electron transfer: In addition to Complexes I and II, glycerophosphate dehydrogenase (GpDH) and electron transferring flavoprotein (ETF) are involved in electron transfer to [[Complex III]].
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| (b) The term „chain‟ suggests a linear sequence, whereas the functional structure of the electron transfer system can only be understood by recognizing '''the convergence of electron flow at the Q-junction''', followed by a chain of Complexes III and IV, mediated by [cytochrome c].
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| Electrons flow to oxygen from either [[Complex I]] with a total of three coupling sites, or from [[Complex II]] and other flavoproteins, providing multiple entries into the Q-cycle with two coupling sites downstream. [[MiPNet12.12]]
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