Figure 13: Postulated action mechanism of low to medium concentrations of chitosan. (1) Chitosan, because of its positively charged amino groups binds to the surface of the cells; (2) this produces the displacement of the K+ attached to the surface, disrupting the equilibrium between the electric plasma membrane difference and the relative internal/external concentrations of the cation; (3) this loss of equilibrium results in the efflux of K+; (4) the efflux of positively charged potassium ions results in an hyperpolarization of the plasma membrane; (5) the hyperpolarization of the plasma membrane greatly increases the uptake of Ca2+ and the efflux of negatively charged small molecules, and (6) metabolic functions as fermentation and respiration are also affected.