Hello! Electric force is inversely proportional to the dielectric constant. In a textbook, this is said to be forty-fold greater for water than the phospholipid membrane. As such, ions are unlikely to cross the plasmamembrane. I assume this has something to do with preferring to stay in water. Here's the thing, this is force, and not energy. Okay, the two are related (from my limited understanding), but not the same. Why would a reduced force between ions lead to the inability of ions to cross the membrane? If the dielectric constant is lower in the plasmamembrane, then the force is greater between ions. I am guessing an increased force means that like charges trying to accumulate to interact ith opposite charges will be unstable? Or something.... There's something obvious I'm missing here. Maybe its that to separate charges to partition the ion into the membrane would require more energy than is available? Any help appreciated.