Slide 22 of 32
Notes:
In thinking about the relevant construct for a diffusional shell, this is really important.
I submit that the relevant measure is likely to be the distance to which some critical concentration threshold is reached. Thinking about antibiotic production, if the antibiotic is toxic to predators at some concentration, the distance that the cell can create this toxicity threshold is very important.
Using this definition, the size of the diffusional shell is linearly proportional to the rate of production q.
This is also relevant for bacteria foraging with extracellular enzymes.
