2.1.6 Explain the importance of the surface area to volume ratio as a factor limiting cell size.
A large number of chemical reactions take place in the cytoplasm of cells. Such reactions are known as the metabolism of the cell. For it to continue substance used in the reactions must be absorbed by the cell and waste products must be excreted through the plasma membrane. The rate at which these substances cross this membrane depends of the surface area. The surface area to volume ratio of a cell is therefore very important. If the ratio is too small, substances will not be able to enter the cell as quickly as needed and waste products would accumulate. The surface area to volume ratio is also important in relation to heat production. If the ratio is too small, the cells may overheat because the metabolism produces heat much faster than is lost over the cell’s surface. It is very easy to see the importance of the surface area to volume ration as a factor limiting cell size.