So on this side we usually have of the endocytotic process, on this end we usually have the exocytotic process. For example, if water actually wants to get in on the lumen side, it has to pass via our passive diffusion and then leave this side via, once again, passive diffusion. But if some other large molecule wants to get in, for example, a sugar molecule, it has to actually get in through our integral protein on this side and then get out through another integral protein on the bottom side. So the other function of our Thai junction is to control the movement of molecules and ions such as water and sugar molecules by only allowing a limited quantity to get into the cell on the apical side and out of the cell on the basil lateral side. This means that if a molecule, such as a water molecule wants to actually get into the cell, it cannot move around the cell because of these tie junctions and it must actually pass through the membrane via the process of passive diffusion. Now, where exactly are these tight junctions found?