Final answer:
Coenzyme Q10 (CoQ), or ubiquinone, is the correct answer as it is the lipid-soluble molecule that shuttles electrons within the mitochondrial inner membrane, playing a pivotal role in the electron transport chain during cellular respiration.
Step-by-step explanation:
The correct answer is C:
CoQ, which stands for Coenzyme Q10 or ubiquinone. This lipid soluble molecule is essential for shuttling electrons within the mitochondrial inner membrane during the process of cellular respiration, specifically within the electron transport chain.
The electron transport chain consists of a series of complexes that facilitate the transfer of electrons from electron donors, such as NADH and FADH2, to electron acceptors, culminating in the reduction of oxygen to water. CoQ functions between complex I (or II) and complex III, receiving electrons from them and transporting these electrons due to its lipid-soluble nature, freely moving through the hydrophobic core of the inner mitochondrial membrane. Once reduced to QH2, it then delivers these electrons to complex III, which continues the electron transport process.
Cytochrome c, on the other hand, is associated with shuttling electrons from complex III to complex IV but does not fulfill the role of lipid-soluble electron shuttle within the membrane itself.