A researcher determined the initial velocity $\left(\mathrm{V}_0\right)$ of an enzyme in three different reactions (corresponding to lines $\mathbf{P}, \mathbf{Q}$ and $\mathbf{R}$ in the graph) with increasing substrate concentrations $([\mathrm{S}])$. The results were analyzed using a reciprocal plot where $1 / \mathrm{V}_0$ is plotted against $1 /[\mathrm{S}]$ (Graph). Reaction 1 was performed without any inhibitory compound. Reaction 2 was performed with compound-X that inhibits enzyme activity by binding to the substrate binding site. Reaction 3 was performed with compoundY that inhibits enzyme activity by binding to a site other than the substrate binding site. If $\mathrm{K}_m$ of the enzyme in reaction 1 is 0.5 mM , then the correct statement(s) from the following options is(are)

• A

  Reaction $\mathbf{1}$ is $\mathbf{P}$, reaction 2 is $Q$ and reaction $\mathbf{3}$ is $R$.
• Correct answer
  B

  Reaction $\mathbf{1}$ is $\mathbf{R}$, reaction $\mathbf{2}$ is $\mathbf{P}$ and reaction $\mathbf{3}$ is $\mathbf{Q}$.
• C

  Reaction $\mathbf{1}$ is $\mathbf{Q}$, reaction $\mathbf{2}$ is $\mathbf{P}$ and reaction $\mathbf{3}$ is $\mathbf{R}$.
• Correct answer
  D

  $\mathrm{K}_m$ of reaction $\mathbf{Q}$ is less than $\mathrm{K}_m$ of reaction $\mathbf{R}$.

Hence, the correct answer is options: 'B', 'D'.