Final answer:
The multiple protein complexes associated with cellular respiration are called D) respirasomes, and they are involved in the electron transport system during oxidative phosphorylation within the inner mitochondrial membrane.
Step-by-step explanation:
The multiple protein complexes associated with cellular respiration are known as respirasomes. These complexes are involved in the electron transport system (ETS), which is a key component of oxidative phosphorylation, where the majority of ATP is generated during cellular respiration. In this process, electrons are transferred from NADH and FADH2 through a series of reactions to a final electron acceptor.
This is accomplished by several membrane-associated protein complexes including Complex I (NADH-coenzyme Q oxidoreductase), Complex III (cytochrome oxidoreductase), cytochrome c, and others within the inner mitochondrial membrane of eukaryotic cells.
Complex I begins the electron transport when NADH donates two electrons, which are then transferred down the chain, ultimately to Complex III. Complex III includes proteins such as cytochrome b, an Fe-S protein, and cytochrome c, all of which help in creating an electrochemical gradient across the membrane, which is used to synthesize ATP. The electron carriers, including CoQ and cytochrome c, have varying redox potentials, ensuring the efficient flow of electrons through the ETS and providing the energy for proton pumping and ATP synthesis.