The article by M. Dixon presents a simple graphical method for determining the Michaelis constant ($K_m$) and the inhibitor constant ($K_i$) of enzymes. The Michaelis constant is determined using Lineweaver & Burk's method, which involves plotting $1/v$ against $1/s$ to transform the Michaelis equation into a linear form. The inhibitor constant is determined by plotting $1/v$ against the inhibitor concentration ($i$) at two different substrate concentrations ($s_1$ and $s_2$). The intersection point of these lines on the left side of the vertical axis gives $-1/K_i$. The article also discusses the determination of $K_m$ from the same plot when $K_i$ is known and the case of non-competitive inhibition, where the lines do not cross but meet on the baseline. This method provides a straightforward way to estimate the constants without complex calculations.The article by M. Dixon presents a simple graphical method for determining the Michaelis constant ($K_m$) and the inhibitor constant ($K_i$) of enzymes. The Michaelis constant is determined using Lineweaver & Burk's method, which involves plotting $1/v$ against $1/s$ to transform the Michaelis equation into a linear form. The inhibitor constant is determined by plotting $1/v$ against the inhibitor concentration ($i$) at two different substrate concentrations ($s_1$ and $s_2$). The intersection point of these lines on the left side of the vertical axis gives $-1/K_i$. The article also discusses the determination of $K_m$ from the same plot when $K_i$ is known and the case of non-competitive inhibition, where the lines do not cross but meet on the baseline. This method provides a straightforward way to estimate the constants without complex calculations.