EN
The paper presents a discussion of the basic assumptions of the Pink's model, which is often used for interpreting phenomena connected with biological membranes. For over ten years now the model has been constantly developed, but its basic assumptions have not ever been evaluated, such as: constant value of surface pressure, independent of composition of the system studied; approximate value (120°) of the angle between -C-C- bonds in alkyl chains of the membrane molecules; or treating both lipid chains as identical and independent.