For fusion of a vesicle with it's target membrane to occur. The membranes have to be brought to within 1.5 nm so the two bilayers can join. Assuming that the relevant portion of the two membranes at the fusion site are circular regions 1.5 nm in diameter, calculate the number of water molecules that would remain between the two membranes ( water is 55.5 m and the volume of a cylinder is πr^2h). Given that an average phosphlpid occupies a membrane surface of 0.2nm^2, how many phospholipids would be present in each f the opposng monolayers at the fusion site? Are there sufficent water molecules to associate with the hydrophillic head groups of this number of phospholipids (10 phospholipids associate with each headgroup)?