The rates at which molecules move are determined by their sizes and shapes. Such movements can be spontaneous, due to diffusion, or produced by sedimentation or electrophoresis. Their sizes and shapes also determine their ability to enter the pores of molecular sieves, as in gel filtration or size exclusion chromatography. These chapters are taken from the larger volume "The Physical and Chemical Basis of Molecular Biology" (2010, Helvetian Press, www.HelvetianPress.com).
