Question

What is the effect of an increase in substrate concentration on an enzyme-catalyzed reaction?

• A. The rate of reaction decreases.
• B. The rate of reaction increases.
• C. The rate of reaction remains unchanged.
• D. The enzyme becomes inactive.

Hint:

Enzyme saturation occurs when all active sites are occupied by substrate molecules, making \( V_{\text{max}} \) the upper limit of the reaction rate.

Answer 1

The Correct Option is B

The correct Option is : 2

Increasing the substrate concentration in an enzyme-catalyzed reaction generally leads to an increase in the reaction rate. This is because more substrate molecules are available to bind to the active sites of the enzyme, resulting in the formation of more enzyme-substrate complexes.
However, this increase continues only up to a certain point known as the maximum velocity (\( V_{\text{max}} \)). Beyond \( V_{\text{max}} \), the rate of reaction plateaus as all active sites of the enzyme molecules are occupied, and adding more substrate does not further increase the reaction rate. 

Michaelis-Menten Kinetics: \[ \text{Rate} = \frac{V_{\text{max}} [S]}{K_m + [S]} \] As \([S]\) increases, the rate approaches \( V_{\text{max}} \). 

Conclusion: An increase in substrate concentration enhances the reaction rate until the enzyme becomes saturated, after which the rate no longer increases.