How does surface area to volume ratio relate to photosynthesis?

1 Answer
Jun 20, 2015

Surface area to volume ratio (SA:V) is important to photosynthesis because plants must balance their need for more surface area to collect sunlight with the fragile nature of the leaves and the rate of water loss.


The equation for photosynthesis is

#"6CO"_2 + "6H"_2"O" → "C"_6"H"_12"O"_6 + 6"O"_2#

A greater SA:V means more area for collection of sunlight and #"CO"_2# and less distance for #"CO"_2# to diffuse into the leaf and for #"O"_2# to diffuse out.

Thin broad leaves provide maximum SA:V, but they also means greater water loss and susceptibility to wind damage.

In drier climates the leaf surface is reduced to slender blades or even to needles to make a smaller SA:V and less evaporative surface.

For example, dill has skinny leaves and thin stems, which means increased SA:V.

Lots of surface area means that there is optimal surface to photosynthesize and produce energy for the plant.