Non-competitive Inhibition?

the substrate doesn't have to change at all. if there is an inhibitor present, all this means is that it is stopping the true substrate from binding to a receptor. if you decrease the substrate concentration, you are just helping the inhibitor in blocking the signal. you could have 100 particles needing to bind to receptors and be ok. if you add an inhibitor, you can still have the 100 particles present but the only thing that changes is their access to the binding site.