Electron Transport Chain MDCAT Quiz; The Electron Transport Chain (ETC) is a critical step in cellular respiration occurring in the inner membrane of the mitochondria. It is the major site of ATP production, utilizing energy from electrons passed through a series of protein complexes and mobile electron carriers. The ETC starts when high-energy electrons, carried by NADH and FADH₂, are passed to the chain. The electrons go through complexes I, II, III, and IV, where their energy is used to pump protons (H⁺) across the mitochondrial membrane, creating an electrochemical gradient called the proton motive force. At the end of the chain, the electrons combine with oxygen (the final electron acceptor) and protons to form water. The proton gradient drives ATP synthase, an enzyme that synthesizes ATP from ADP and inorganic phosphate. The ETC produces the bulk of ATP in cellular respiration, yielding approximately 32-34 ATP molecules. For MDCAT students, understanding the ETC is essential for questions related to energy production and metabolic processes.
Test Your Knowledge with an MDCAT Quiz
Take an MDCAT Quiz on the Electron Transport Chain to strengthen your understanding of how ETC contributes to ATP production. It will cover the role of NADH and FADH₂, the function of protein complexes, the importance of the proton gradient, and the role of oxygen as the final electron acceptor. Regular practice of these quizzes will prepare you for MDCAT questions on cellular respiration and bioenergetics.
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Free Flashcards for Quick Revision
Free Flashcards on the Electron Transport Chain are very concise and present summaries of the main steps, components, and processes in the ETC. These include electron flow through the protein complexes, the generation of the proton gradient, and the synthesis of ATP. Flashcards are an excellent way to quickly revise these core concepts so that you’re prepared for questions related to the MDCAT.
Mastering the Electron Transport Chain is essential in understanding how cells efficiently produce energy by the process of aerobic respiration. Use our quizzes and flashcards to build your knowledge and improve your preparation for the MDCAT exam!
What is the primary function of the electron transport chain?
Generate ATP
Where does the electron transport chain occur in eukaryotic cells?
Inner mitochondrial membrane
What is the final electron acceptor in the electron transport chain?
Oxygen
Which molecule donates electrons to the electron transport chain?
NADH
What is the energy used for during the electron transport chain?
Pump protons across the membrane
What is the result of proton pumping in the electron transport chain?
Proton gradient formation
What is the enzyme responsible for synthesizing ATP in the electron transport chain?
ATP synthase
What is the movement of protons back across the membrane called?
Chemiosmosis
What is the primary source of electrons for the electron transport chain?
NADH and FADH2
What is the role of oxygen in the electron transport chain?
Final electron acceptor
What is the main product of the electron transport chain?
ATP
Which protein complex in the ETC transfers electrons to oxygen?
Cytochrome c oxidase
What is produced when oxygen accepts electrons in the ETC?
Water
What is the total number of ATP molecules produced by the electron transport chain?
34 ATP
What is the role of Complex I in the electron transport chain?
Accepts electrons from NADH
Which molecule donates electrons to Complex II of the electron transport chain?
FADH2
What is the role of cytochrome c in the ETC?
Transfers electrons
What happens to the energy released during electron transport?
Used to pump protons
What is the primary location of the ETC in prokaryotes?
Plasma membrane
What is the energy currency molecule generated by the electron transport chain?
ATP
What creates the electrochemical gradient in the ETC?
Proton pumping
What is the term for the movement of protons back into the mitochondrial matrix?
Chemiosmosis
What is the name of the process that couples the electron transport chain to ATP synthesis?
Oxidative phosphorylation
Which complex in the ETC does not pump protons?
Complex II
How are electrons transferred between complexes in the ETC?
By mobile carriers
What is the mobile carrier that transfers electrons from Complex III to Complex IV?
Cytochrome c
What is the mobile carrier that transfers electrons from Complex I to Complex III?
Ubiquinone
What is the waste product of the electron transport chain?
Water
Which process uses the proton gradient created by the ETC?
ATP synthesis
What happens if oxygen is not available for the ETC?
The chain stops
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