Both substrate and inhibitor try to bind to the active site
Inhibition can be reversed when subtrate is at very high levels
Inhibitor binds at allosteric site on the enzyme
Many drugs used as medicines work by this mechanism
Inhibitor binding may covalently alter a functional group on the enzyme
can poison the enzyme permanently
Substrate has similar shape as inhibitor
Inhibitor binding alters 3D shape of enzyme making it unsuitable for substrate binding