(A) The theoretical dependence of the equilibrium concentration of a solute in intracellular water on its concentration in the medium, provided that (i) the solvent capacity of water in the cell and the medium is the same, (ii) the solute is not adsorbed on intracellular structures. (B) The dependence of the lactose content (free plus bound) in yeast (C_c, in mM of intracellular water) on its concentration in the medium (C_s, in mM) in equilibrium condition. (C) The dependence of the equilibrium concentration of lactose in intracellular water on the concentration of the sugar in the medium: the bound sugar is subtracted from the linear part of the experimental curve ([11], Fig. 56, redrawn). See text for details.