Oligomycin (an ATP-synthase inhibitor) was added in a separate trial. O2 consumption was monitored before and after addition.
The plateau after oligomycin demonstrates:
- A
Mitochondria die immediately.
- Bcheck_circle
Coupling: blocking ATP synthesis backs up the proton gradient and slows the ETC.
- C
Oligomycin destroys the ETC.
- D
ATP is required for substrate uptake.
Explanation
Without H+ flow through ATP synthase, the proton-motive force builds up and inhibits further proton pumping by the ETC. O2 consumption stalls because ETC and ATP synthesis are coupled.