Surface+area+to+volume+ratio+and+how+it+affects+membrane+transport

=**Surface Area to Volume Ratio**=

By Mackenzie
There are all different types of transports in a cell including simple diffusion, facilitated diffusion, osmosis, filtration, active transport, endocytosis, and exocytosis. This movie will explain these transport processes in more detail.

media type="youtube" key="ls_mdBQVGJ4" height="315" width="560"

As a cell’s volume (cytoplasm) expands and increases more rapidly then it’s surface area (plasma membrane). The volume of a cell determines the amount of nutrients that is needed and the amount of waste removal that needs to leave the cell, however the amount that the cell is capable of removing or taking in depends on the size of the surface area. This is because the plasma membrane controls the amounts of waste removal and nutrients enters and leaves the cells.

As the cell increases its chemical activity increases meaning it needs more substances going in to fuel these chemical reactions and it needs more waste products removed. However when the cell reaches a certain size the diffusion of substances is no longer fast enough for the increasing volume of the cell and its chemical activity. This then causes the surface area to volume ratio to decrease causing the cell to overheat.

** Volume (cytoplasm) **

 * ** Hypothetical Cell ** ||  ** Cell A **  ||  ** Cell B **  ||  ** Cell C **  ||
 * ** Diameter (cm) ** ||  1.0   ||   2.0   ||   3.0   ||
 * ** Surface Area (cm **** ² **** ) ** ||  3.14   ||   12.57   ||   28.28   ||
 * ** Volume (cm **** ³ **** ) ** ||  0.52   ||   4.19   ||   14.14   ||
 * ** Surface area to volume ratio. ** ||  6:1   ||   3:1   ||   2:1   ||