Membranes are the barriers that separate the inside living p

Membranes are the barriers that separate the inside “living” part of a cell from the outside “non-living” surroundings. Given that all new materials entering the cell must first cross the membrane, and given that there is a limit to how much “stuff” can cross a unit area of membrane in a given time, explain how this might set an upper limit on how big a single cell can be. In composing your answer, describe the relation between cell size, cell volume, and cell membrane area

Solution

With increase in cell size, the cell volume and surface area increases. The cells allow only limited “stuff” to leave and enter into the cell because allowing too much of the material into the cell will increase the cell volume and size, and allowing too much efflux will reduce the cell size and volume. As the molecules pass through the cell membrane, the quantity of “stuff” passing through the cell is determined by the surface area of the cell; the more is the surface area means the more will be the transportation.