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.

Explanation:

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.

bioweb.uwlax.edu