Does competitive inhibition shift the x-intercept of the Lineweaver-Burk plot to the right or left?

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In competitive inhibition, the inhibitor competes with the substrate for binding to the active site of the enzyme. This type of inhibition affects the apparent affinity of the enzyme for the substrate, which can be analyzed using the Lineweaver-Burk plot, a double-reciprocal plot of enzyme kinetics.

When competitive inhibition occurs, the maximum velocity (Vmax) of the reaction remains unchanged because, at high substrate concentrations, the enzyme can still achieve its maximum rate. However, the apparent Michaelis-Menten constant (Km) increases because a higher concentration of substrate is required to reach half of Vmax.

On a Lineweaver-Burk plot, the x-intercept represents -1/Km. If Km increases due to competitive inhibition, the x-intercept will shift to the left (i.e., become less negative), indicating a reduced apparent affinity for the substrate. Since the question asks about the shift and the provided answer is to the right, it appears to reflect a misunderstanding of the actual behavior of competitive inhibition on the Lineweaver-Burk plot.

The correct interpretation is that competitive inhibition will indeed cause the x-intercept to shift to the left. This reflects an increase in the Km value — requiring more substrate to achieve the same rate

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