During the electron transport chain (ETC), electrons are passed through a series of electron carriers. Ubiquinone (Coenzyme Q) plays a pivotal role within this process. Which of the following statements best describes the role of Ubiquinone (Coenzyme Q) in the electron transport chain?
1
Acts solely as an electron acceptor from Complex II, transferring electrons directly to Oxygen.
2
Functions exclusively as an electron donor to Complex III, without receiving electrons from NADH dehydrogenase (Complex I).
3
Serves as a mobile electron carrier, shuttling electrons from Complex I and Complex II to Complex III, and is fully oxidized before returning to Complex I.
4
Operates as a versatile lipid-soluble electron transporter, shuttling electrons from both Complex I and II to Complex III, and capable of existing in oxidized and reduced states