The protein ?-lactalbumin (molecular weight = 14,000) has been studied under different solution conditions by dynamic light scattering. At pH 7 and 40°C in a dilute solution the diffusion coefficient was found to be 14.25×10-7 cm2/s. (a) If the viscosity of the solvent was 0.0101 P, estimate the diameter of the protein assuming that it is spherical in shape. (b) As pH < 2 this protein becomes inactive and changes spectral characteristics. Under these conditions the diffusion constant was found to be 12.80×10-7 cm2/s. Calculate the change in volume of the protein (assume all else remained the same).