NEW! Cytochrome c:Ubiquinol Oxidoreductase: Physiology, Biochemistry, and Mechanism

This video explains the mechanism and physiology of cytochrome C ubiquinol oxidoreductase, also known as Complex 3, in the mitochondrial respiratory chain. It details the Q cycle, electron transfer processes, and the role of coenzyme Q. The video also covers the enzyme's inhibitors and the formation of free radicals, emphasizing the importance of understanding these processes for cellular respiration.

What is another name for cytochrome C ubiquinol oxidoreductase?

• Complex 2

• Complex 4

• Complex 1

• Complex 3

What is the primary function of cytochrome C in the electron transport chain?

• Catalyze reactions

• Transport electrons

• Synthesize ATP

• Pump protons

Which residue in the active site of cytochrome C ubiquinol oxidoreductase acts as a proton exchanger?

• Serine

• Tyrosine

• Histidine

• Lysine

What is the role of the Rieske iron-sulfur center in the Q cycle?

• Proton transfer

• Electron transfer

• ATP synthesis

• Oxygen binding

How many protons are pumped into the inner membrane space during one cycle of cytochrome C ubiquinol oxidoreductase?

• Eight

• Two

• Four

• Six

What is the reduced form of cytochrome C called?

• Radical cytochrome C

• Ferrous cytochrome C

• Ferric cytochrome C

• Oxidized cytochrome C

Which inhibitor blocks the transfer of electrons from heme high potential to oxidized coenzyme Q?

• Myxothiazole

• Cyanide

• Antimycin A

• Rotenone

What is the consequence of inhibiting electron transfer in the respiratory chain?

• Formation of free radicals

• Enhanced proton pumping

• Increased ATP production

• Decreased oxygen consumption

What is the role of superoxide dismutase in the cell?

• Pumps protons

• Neutralizes free radicals

• Transfers electrons

• Synthesizes ATP

Which molecule is a free radical that can be formed in the respiratory chain?

• Water

• Superoxide

• Carbon dioxide

• NADH