A section of membrane with an aquaporin (AQP) has a water transport rate of about 2 billion water molecules per second ( 2109 molecules. s1 ). Removal of the AQP lowers the rate to about 30 million water molecules per second ( 3.0107moleculess1) By what factor does the aquaporin increase the rate of water transport in this example? Note that this is a hypothetical situation, and does not reference any specific data or study. However, 3109molecules/s is a common estimate given for flow through an AQP. Water flow through an AQP is often stated in terms of a water permeability coefficient with units of centimeters per second. 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