A researcher determined the initial velocity ( V ₀ ) of an enzyme in three different reactions (corresponding to lines P , Q and R in the graph) with increasing substrate concentrations ([ S ]) . The results were analyzed using a reciprocal plot where 1 / V ₀ is plotted against 1 /[ S ] (Graph). Reaction 1 was performed without any inhibitory compound. Reaction 2 was performed with compound-X that inhibits enzyme act