The highly organized condition in most cells that is characterized by a distinct apical-basal axis with an asymmetric distribution of cytoplasmic organelles. This phenomenon of polarization is critical for living organisms to function. For example, cells in secretory organs such as the gall bladder generally secrete only at one end where secretory vesicles are localized. Another example would be a cell in the intestinal wall that must collect nutrients on the side near the lumen and transport them through the cell to the opposite end, where they can be delivered to the blood supply for transport to the rest of the body. Clearly, this cell must exhibit a polarized distribution of membrane proteins so that those necessary for sugar uptake are concentrated in the membrane facing the lumen and those needed to move the sugar out of the cell are located at the opposite side.