The correct Option is : 2
Elevating substrate concentration in enzyme-catalyzed reactions typically escalates the reaction rate. This occurs as a greater number of substrate molecules become available to bind with enzyme active sites, thereby forming more enzyme-substrate complexes.
This rate augmentation persists only until a plateau is reached, identified as the maximum velocity (\( V_{\text{max}} \)). Subsequent to \( V_{\text{max}} \), the reaction rate stabilizes because all enzyme active sites are fully occupied; additional substrate will not further accelerate the process.
Michaelis-Menten Kinetics: \[ \text{Rate} = \frac{V_{\text{max}} [S]}{K_m + [S]} \] As \([S]\) rises, the rate asymptotically approaches \( V_{\text{max}} \).
Conclusion: An increase in substrate concentration boosts reaction rate until enzyme saturation is achieved, at which point the rate remains constant.