How does a cells surface area to volume ratio limit its size?
1 Answer
The only practical limitation may be the structural integrity of the cell wall.
Explanation:
This is also the primary reason that the popular SciFi trope of "enlarged species" (e.g. ants, spiders, wasps) is impossible. From basic geometry and physics we know that the volume - and thus mass - increases as a cube of the central radius, while the area only increases as a square.
Thus, at some point, the strength of the cell wall to support the interior fluids and organisms will no longer be able to contain them, and the cell would rupture and die. Cell sizes cover an extremely large range in any case (0.1nm to 3m!), so a final "limit" may not yet be known.
An extensive list of single cell sizes by type is here:
https://en.wikibooks.org/wiki/Cell_Biology/Introduction/Cell_size
What limits cell sizes?
Prokaryotes — Limited by efficient metabolism
Animal cells (eukaryotic) — Limited by many factors, some unknown
Plant cells (eukaryotic) — Have large sizes due to large central vacuole, which is responsible for their growth
