why are proton pumps in root-hair plasma membranes important? why are proton pumps in root-hair plasma membranes important? they allow toxins to be concentrated in vacuoles, so the toxins do not poison enzymes in the cytoplasm. they pump protons into cells, generating a membrane potential (voltage). they set up the membrane voltage required for action potentials to occur. they set up an electrochemical gradient that makes it possible for roots to absorb cations and anions.