If a molecule has a larger polar surface area of more than 140 angstroms squared (Å2), it is likely to face difficulty in getting through cell membranes. This occurs because cell membranes, being composed of a nonpolar or hydrophobic core, don't allow polar molecules to pass through. Furthermore, biologists and pharmacologists need to carefully take into account the polar surface area of a compound before designing drugs, as they must be able to penetrate cell membranes to be effective.What is the molecular PSA?