Answer:
It adjusts to different oxygen levels.
The cytochrome bo branch operates when E coli is growing rapidly with good aeration.
The cytochrome bd branch operates at low oxygen conditions. It is located in the outer membrane.
Step-by-step explanation:
Electron transport chains of Escherichia coli are composed of different dehydrogenase and terminal reductase which is linked by quinones. It adjusts to different oxygen level because Oxygen is preferred electron acceptor and represses the terminal reductase of anaerobic.