Where is ATP synthase located within the mitochondria?
ATP synthase is located in the inner mitochondrial membrane.
What is the primary function of ATP synthase in oxidative phosphorylation?
The primary function of ATP synthase is to synthesize ATP from ADP and inorganic phosphate, using the energy from the proton gradient generated by the electron transport chain.
Which prosthetic groups are found in Complex I of the electron transport chain?
Complex I contains flavin mononucleotide and iron sulfur proteins as prosthetic groups. These facilitate electron transfer from NADH to ubiquinone.
How many protons does Complex III pump into the intermembrane space per net reaction?
Complex III pumps 4 protons into the intermembrane space per net reaction. This occurs during the Q cycle as electrons are transferred to cytochrome c.
What is the role of cytochrome c in the electron transport chain?
Cytochrome c transfers electrons one at a time from Complex III to Complex IV. It acts as a mobile electron carrier between these complexes.
What is unique about the Q cycle in Complex III?
The Q cycle allows ubiquinone to transfer two electrons at a time, while cytochrome c can only accept one electron at a time. This mechanism ensures efficient electron transfer and proton pumping.
Which enzyme in the electron transport chain is also part of the citric acid cycle?
Succinate dehydrogenase, which is Complex II, is also an enzyme in the citric acid cycle. It catalyzes the oxidation of succinate to fumarate.
How does oxygen function in the electron transport chain?
Oxygen acts as the final electron acceptor in the electron transport chain. It is reduced to water at Complex IV after receiving electrons from cytochrome c.
What are the three sources from which ubiquinone can receive electrons?
Ubiquinone can receive electrons from Complex II, beta oxidation, and NADH via FAD. These multiple entry points contribute to its central role in the electron transport chain.
What happens to protons during the reduction of oxygen to water in Complex IV?
Protons are taken in by Complex IV along with oxygen to form water. This process also contributes to the proton gradient across the inner mitochondrial membrane.