Final answer:
Ubiquinone and cytochrome c are mobile electron carriers within the electron transport chain (ETC), transferring electrons between complexes, unlike other components that are membrane-bound. Mitochondrial ETC and E. coli ETC differ in location and membrane structure, with mitochondria having a matrix and cristae.
Step-by-step explanation:
The electron transport chain (ETC) is a crucial component of cellular respiration, present in both eukaryotic and prokaryotic cells. The roles of ubiquinone (CoQ) and cytochrome c within this system are paramount, as they are mobile electron carriers.
This is in contrast to components such as NADH dehydrogenase and succinate dehydrogenase, which are bound to the inner mitochondrial membrane. CoQ and cytochrome c facilitate the transfer of electrons between the various complexes of the ETC.
In mitochondria, the ETC is located in the inner membrane, which is folded into cristae, thereby increasing the surface area for reactions. Mitochondria, being derived from bacterial ancestors, contain their own DNA and ribosomes, similar to those of prokaryotic cells, like E. coli.
However, differences between mitochondrial ETC and E. coli ETC include the location (E. coli's ETC is in the plasma membrane) and structural differences in membrane folding and presence of a matrix in mitochondria. Overall, ubiquinone and cytochrome c are essential for shuttling electrons through the ETC, ultimately contributing to the generation of ATP by chemiosmosis.