Protozoan motility You are observing the motion of spherical protozoa through the microscope. Methyl cellulose solution is frequently employed in microscopy to slow motile species and render them convenient for observation. Assuming the protozoa are moving in creeping flow and that the organism's energetic commitment to motion is constant, what effect on velocity would you expect from a 10-fold increase in viscosity of the fluid surrounding the cells? (Hint: See Equation 5.2.1, Bioseperations Science and Engineering.)

(5.2.1) 4 dv m dt = Fir +For + F01 =() za?por-(1)ra?go* r 67 a AR where subscripts designate forces in the R direction, due to i, inertial acceleration, b, buoyancy due to the density of the medium po through which the particle sediments, and d, the Stokes drag force, which under conditions of creeping flow is proportional to the velocity v and viscosity [1]. Solving Equation (5.2.1) for velocity in a centrifugal field at steady state (all forces balanced, so a dv/dt = 0) gives