Flashcards
Electron Transport Chain
Cards in this deck (25)
- 1Where does the Electron Transport Chain (ETC) occur?In the inner mitochondrial membrane.
- 2What is the primary function of the Electron Transport Chain (ETC)?To transfer electrons from NADH and FADH₂ to oxygen, creating a proton gradient used for ATP synthesis.
- 3What is the final electron acceptor in the ETC?Oxygen (O₂), which forms water (H₂O).
- 4Which complexes pump protons into the intermembrane space?Complex I (4 H⁺), Complex III (4 H⁺), Complex IV (2 H⁺).
- 5Which complex does NOT pump protons?Complex II (Succinate Dehydrogenase).
- 6What is the role of Coenzyme Q (Ubiquinone)?It is a mobile electron carrier that transfers electrons from Complex I and II to Complex III.
- 7What is the role of Cytochrome C?It is a small, water-soluble protein that transfers electrons from Complex III to Complex IV.
- 8What is the ATP yield per electron donor?A: NADH → 2.5 ATP, FADH₂ → 1.5 ATP.
- 9What is the effect of inhibitors on the ETC?They block electron transport, preventing ATP synthesis.
- 10Name an inhibitor of Complex I (NADH Dehydrogenase).Rotenone or Barbiturates (e.g., Amobarbital).
- 11Name an inhibitor of Complex III (Cytochrome bc₁ Complex).Antimycin A.
- 12Name inhibitors of Complex IV (Cytochrome c Oxidase).Cyanide (CN⁻), Carbon Monoxide (CO), Azide (N₃⁻).
- 13What does DNP (2,4-dinitrophenol) do to the ETC?It is an uncoupler, dissipating the proton gradient, preventing ATP synthesis while still consuming oxygen.
- 14What is thermogenin (UCP1) and where is it found?It is an uncoupling protein found in brown adipose tissue, producing heat instead of ATP.
- 15What drives ATP synthesis in oxidative phosphorylation?The proton gradient established by the ETC.
- 16How does Complex I contribute to ATP generation?By transferring electrons from NADH to Coenzyme Q and pumping 4 protons.
- 17How is Complex II different from Complex I?Complex II transfers electrons from FADH₂ but does NOT pump protons.
- 18What happens if Complex IV is inhibited?Oxygen cannot be reduced to water, halting the ETC and ATP synthesis.
- 19What is the purpose of the proton gradient in the ETC?It provides the energy required for ATP synthesis by ATP synthase.
- 20How many ATP molecules are produced per glucose molecule from the ETC?Approximately 28 ATP.
- 21What role does oxygen play in the ETC?Oxygen acts as the final electron acceptor, allowing the continuation of electron transport.
- 22What is the Q cycle in Complex III?A mechanism that enhances electron transfer efficiency and pumps 4 protons.
- 23What happens if ATP synthase is inhibited?Protons accumulate in the intermembrane space, disrupting ATP production.
- 24What is the role of Fe-S clusters in the ETC?They assist in the transfer of electrons between complexes.
- 25How do reactive oxygen species (ROS) form in the ETC?Due to electron leakage from the chain, leading to partial reduction of oxygen