Why are active transport mechanisms sensitive to many metabolic poisons?

1. Active transport mechanisms depend on a cell's metabolism for the energy they spend. 2. They are therefore sensitive to many metabolic poisons that interfere with the supply of ATP. 3. Cut the ATP supply and the pumps stop, even though the proteins themselves are intact. 4. Passive routes such as simple diffusion would keep working under the same poison, because they spend no ATP. 5. Dissolving the bilayer would destroy the whole membrane rather than selectively disable pumps. 6. Poisons do not reverse gradients, they remove the cell's ability to defend them. _Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 5 "Structure and Function of Plasma Membranes", section 5.3 Active Transport_