A section of membrane with an aquaporin (AQP) has a water transport rate of about 4 billion water molecules per second (4 x 10° molecules s¹). Removal of the AQP lowers the rate to about 30 million water molecules per second (3 x 107 molecules. s¹). By what factor does the aquaporin increase the rate of water transport in this example? Number ☐ Note that this is a hypothetical situation, and does not reference any specific data or study. However, 3 x 10° molecules/s is a common estimate given for flow through an aquaporin (AQP). Water flow through an AQP is instead often stated in terms of a water permeability coefficient with units of cm/s. The actual value varies with osmotic pressure and type of AQP, among other factors. Some studies have shown around a 10-fold decrease in water permeability after AQP removal.