= Pure noncompetitive inhibition
Set $K_i=K_i'$, so that $\alpha=\alpha'$. The <reversible enzyme inhibition> equation reduces to
$$
v=\frac{1}{\alpha}\frac{V_{\max}s}{K_M+s},\qquad
V_{\max,\rm app}=\frac{V_{\max}}{\alpha},\quad K_{M,\rm app}=K_M.
$$
At the chosen $I=30\,\mathrm{\mu M}$, every <reaction rate> is one quarter of its uninhibited value. The plateau falls to $25\,\mathrm{\mu M\,min^{-1}}$, but half that plateau still occurs at $s=20\,\mathrm{\mu M}$. Increasing <substrate> cannot restore the uninhibited plateau. An unchanged apparent <Michaelis constant> here expresses equality of the two binding effects, rather than an absence of inhibitor binding to the <enzyme-substrate complex>.
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