Exercise 1
The sedimentation of bovine serum albumin (dBsA = 1.106 g/cm3) was measured in water at 298 K at a spinning speed of 56 850 rpm.
Calculate the sedimentation coefficient, the molar mass and the frictional coefficient of the BSA given a diffusion coefficient of 6.9 x 10-12 1U2/S. State any assumptions.
Exercise 2
The sedimentation and diffusion coefficients for myoglobin in dilute aqueous solution at 20 °C are 2.04 x 10-13 s and 1.13 x 10-1° m2 sel,
respectively. The partial specific volume of the protein is 0.741 cm3 g-1, the density of the solution is 1.00 g cm-3 and the coefficient of viscosity of the solution is 1.00 x 10-3 kg m-1.s-1. Calculate (a) the relative molecular mass and (b) the frictional ratio of this protein.
Exercise 3:
At 20.0 0C, a polymer (M = 170. kg/mol) having a specific volume of 0.773 cm3/g is centrifuged in water (density of water = 0.998 g/cm3).
Calculate the relative concentration of the polymer at r - 7.0 cm vs. r - 6.0 cm if the centrifuge is turning at 45000 rpm.
Exercise 4:
In an electrophoresis experiment, spherical colloidal particles of diameter 0.5 1-1.M are dispersed in a solution of 0.10 mon NaCl. If the particles are observed to cover a distance of 120 1.1M in 5.0 s, calculate an estimate of the error in the electrophoresis measurement arising from the Brownian displacement of the particle that occurs during the experiment.