Question

Consider the question of size from a molecular perspective. What specific problems are solved by becoming bigger? How does a larger cell volume help and/or hinder cell functions?

Answer 1

As the cell gets bigger or larger, the surface area to the volume ratio gets smaller. When the cell grows beyond a certain limit, lesser amount of materials would be able to pass the membrane. But, the rate of diffusion of the materials in and out of the membrane gets easier. Thus, exchange of O2-CO2 increases. If the surface area to volume ratio gets too small, the growth of the cell is hindered and organelles are needed to help transport materials around the cell. The large volume of a cell is the inner volume i.e. inner to the plasma membrane. Bigger cell means greater accommodation of cellular organelles and thus more functional activities.Moreover, a unicellular organism is able to carry out all the functions by itself, all the functions are benefited by the large volume.