Principles of Biochemistry Volume 2 - A. Lehninger 1985

Bioenergetics and Metabolism
Electron Transport, Oxidative Phosphorylation, and Regulation of ATP Synthesis
The electron transport chain includes a large number of carriers

The mitochondrial Respiratory Chain includes A large number of diverse Proteins that sequentially transfer electrons from substrates to oxygen. Figure 17-1 shows only seven electron carriers within the respiratory chain, but, as noted above, this is a simplified representation. In reality, the Electron Transport Chain contains at least 15 (and possibly more) chemical groups capable of accepting and donating reducing equivalents in the sequence shown in Figure 17-5.

A notable feature is The Diversity of chemical groups dedicated to electron transfer, all of which are protein-bound. These include: nicotinamide adenine dinucleotide (NAD), which Functions as part of various dehydrogenases; flavin mononucleotide (FMN), associated with NADH dehydrogenase; ubiquinone, or coenzyme Q (a lipid-soluble quinone with an isoprenoid side chain), which can function in association with one or more proteins; iron-containing proteins of two different types: iron-sulfur centers (Fe-S) and Cytochromes; and finally, the copper of cytochrome aa3. A third important point is that all of these electron-carrying proteins are Water-insoluble and embedded within The inner mitochondrial membrane.



Last update: 06/08/2026

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