why does the maximum initial reaction rate cannot be reached at low substrate concentrations.
The particles are too far apart, so the reaction rate has to include migration time.
The maximum initial reaction rate, also known as Vmax, represents the maximum rate at which an enzymatic reaction can occur under ideal conditions. It is determined by the concentration and activity of the enzyme.
At low substrate concentrations, the enzyme-substrate complex formation is limited because there are fewer substrate molecules available to bind with the enzyme. The rate of reaction depends on the collision between the enzyme and the substrate.
When substrate concentration is low, there is not enough substrate to saturate all the enzyme active sites. Hence, some enzyme molecules may not be engaged in catalytic activity due to the lack of substrates. As a result, the rate of reaction will be lower, and it will take longer for the reaction to reach Vmax.
To reach the maximum initial reaction rate at low substrate concentrations, you would need to increase the substrate concentration to saturate all available enzyme active sites. By doing so, all enzyme molecules will have a substrate to bind with and catalyze the reaction, maximizing the rate of reaction. This condition is known as the enzyme operating at maximum velocity.