Specificity: only molecules with the requisite chemical structure are transported Saturation: as the concentration of the transported compound is increased, the rate of transport at first increases, but eventually a concentrations reached after which the transport rate increases no further. Competitive inhibition: structurally related molecules may compete for transport• Saturation: as the concentration of the transported compound is increased, the rate of transport at first increases, but eventually a concentrations reached after which the transport rate increases no further. • Specificity: only molecules with the requisite chemical structure are transported. • Competitive inhibition: structurally related molecules may compete for transport