EN
In the present study, we discussed the biophysical mechanisms of stationary wa ter ex change with the surroundings by the Nitella translucens and Chara corallina plants. It was postulated that these plants, which subsist under total immersion in a water medium, conduct water exchange within single cells individually. With the application of the equations of mechanistic formalism for membrane transport to our investigations (Kargol and Kargol 2000, Kargol 2001, Kargol 2002, Kargol and Kargol 2003, 2003*), it was demonstrated that individual cells of these plants can simultaneously absorb and remove considerable amounts of water at constant cell volume, i.e. under stationary conditions. Water absorption is osmosis-driven, and its removal is effected by the cell turgor pressure.