02.11.09. Bacteria take in nutrient molecules through chemoreceptor patches on their cell walls (image from Berg and Purcell, Biophys J, 1977). The efficiency of this process depends in part on the fraction of the bacterium's surface that is covered by receptors. Using toy models of bacteria with receptors represented by different shapes, students used their own measurements and area calculations to answer the question: if a nutrient molecule hits the surface of the bacterium, what is the probability that it gets absorbed?
