What impact does competitive inhibition have on the overall reaction velocity at high substrate concentrations?

What impact does competitive inhibition have on the overall reaction velocity at high substrate concentrations?

• A. Vmax is decreased
• B. Vmax is unchanged
• C. Vmax can never be reached
• D. Vmax is exactly halved

Answer: (B)

In competitive inhibition, an inhibitor competes with the substrate for binding to the active site of the enzyme. At high substrate concentrations, the effect of the competitive inhibitor can be overcome. This means that as more substrate is added, the likelihood of substrate molecules binding to the enzyme increases, effectively outcompeting the inhibitor for access to the active site. Since competitive inhibition does not affect the maximum rate of the reaction (Vmax), the enzyme can still reach this maximum rate when sufficient substrate is available. Therefore, at very high substrate concentrations, the enzyme will operate at its maximum velocity, and the presence of the inhibitor will not change Vmax. The overall reaction velocity can increase and eventually reach the same maximum as it would without the inhibitor. This understanding is crucial for interpreting enzyme kinetics and determining how different inhibitors can influence enzyme activity.

In competitive inhibition, an inhibitor competes with the substrate for binding to the active site of the enzyme. At high substrate concentrations, the effect of the competitive inhibitor can be overcome. This means that as more substrate is added, the likelihood of substrate molecules binding to the enzyme increases, effectively outcompeting the inhibitor for access to the active site.

Since competitive inhibition does not affect the maximum rate of the reaction (Vmax), the enzyme can still reach this maximum rate when sufficient substrate is available. Therefore, at very high substrate concentrations, the enzyme will operate at its maximum velocity, and the presence of the inhibitor will not change Vmax. The overall reaction velocity can increase and eventually reach the same maximum as it would without the inhibitor.

This understanding is crucial for interpreting enzyme kinetics and determining how different inhibitors can influence enzyme activity.