Molecular Weight, Molecular Volume, and Hydration of Proteins in Solution

1. The gram molecular weight of a substance may be calculated from the osmotic pressure of its solution. 2. The radius of the hydrated molecule and, hence, the gram molecular volume of the hydrated solute may be determined from diffusion measurements. The hydration of the molecules may, therefore, be calculated from osmotic pressure and diffusion measurements. 3. Hydration may also be determined by viscosity measurements. Hydration of crystalline hemoglobin, crystalline trypsin, and gelatin have been determined by these methods and found to be as follows: See PDF for Structure.