Multiple Choice
In cellular respiration, which stage produces the greatest amount of ATP per glucose molecule in aerobic conditions?
9
views
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation
Oxidative Phosphorylation 1
Multiple Choice
In oxidative phosphorylation, cells produce ATP most efficiently in the presence of which of the following conditions?
A
Molecular oxygen () as the terminal electron acceptor
B
A complete inhibition of ATP synthase (Complex V) while the electron transport chain remains active
C
An uncoupler that dissipates the proton gradient across the inner mitochondrial membrane (e.g., DNP)
D
Only fermentation with pyruvate reduced to lactate (no functional electron transport chain)
Verified step by step guidance1
Understand the role of molecular oxygen (O\_2) in oxidative phosphorylation: it acts as the terminal electron acceptor in the electron transport chain (ETC), allowing electrons to flow through the complexes and enabling proton pumping to create a proton gradient.
Recognize that the proton gradient generated by the ETC across the inner mitochondrial membrane is essential for ATP synthesis by ATP synthase (Complex V). This gradient stores potential energy used to convert ADP and inorganic phosphate into ATP.
Analyze the effect of inhibiting ATP synthase (Complex V): although the ETC may remain active and continue pumping protons, ATP production stops because the proton gradient cannot be used to drive ATP synthesis.
Consider the impact of uncouplers (e.g., DNP) that dissipate the proton gradient: they allow electron transport and oxygen consumption to continue but prevent ATP synthesis by collapsing the proton motive force, leading to inefficient ATP production.
Evaluate fermentation conditions where the ETC is non-functional: ATP is produced only by substrate-level phosphorylation, which is much less efficient than oxidative phosphorylation that depends on oxygen as the terminal electron acceptor.
Related Videos
Related Practice
