Absorptive Area

∞ generated and posted on 2016.01.09 ∞

Region over which acquisition of nutrients and other substances can occur.

The rate at which organisms can transfer materials from one compartment to another can be limited on a per unit area basis. These limitations can be a function of rates of collision between substance and absorptive area or instead the number of proteins over that area that the substance is able to interact with. In either case, one solution to increasing rates of transfer is to increase the area over which this transfer can occur.

Note that increasing absorptive area itself can have costs, as too can increasing protein densities per unit area. These increases can have the effect of modifying the shape of these surfaces, which is relevant to solving surface-to-volume ratio problems associated with cells or organisms becoming larger. Indeed, the major concern that arises when surface area increases cannot keep up with volume increases is one of absorptive area not keeping up with the total volume that needs literally to be fed.

One typically sees absorptive area considered in terms of the surface area of the small intestine, i.e., over which absorption in nutrients in animals occurs. This concept is relevant to the roots of plants, however, to the hyphae of fungi and, of course, to the surfaces area of cells in general.