Answer:
Ether-linked lipids
Step-by-step explanation:
Most organisms found in the Archaea are found in extreme enviroments such as very high temperatures. They are generally called Thermophiles.
In order to survive high temperatures, their cell membrane membrane contains ether-linked lipids. This is because these lipids are Thermo-stable. and can not be easily degraded by the high temperatures.
They also have a limited permeability to proton even at high temperatures hence maintaining a viable proton motive force even at these extreme temperatures.