Enzymologists involved in the study of enzyme inhibition under classical (as opposed to tight-binding) experimental conditions are accustomed to viewing and analyzing plots of k obs against the inhibitor concentration [I] 0 , in an effort to discern the number of binding steps involved in the inhibition mechanism. A strictly linear plot normally signifies a one-step binding model, whereas a hyperbolic plot (with an nonzero offset on the Y-axis) signifies a two-step binding model. Under tightbinding experimental conditions, when k obs values are derived from Eqn (4), it is impossible to discern the number of binding steps from the shape of the plot. Nevertheless visualizing the expected shape of such plots might prove illuminating. An illustrative example is shown in Figure . [I] 0 plot under the tight-binding experimental conditions. For explanation see text.