The velocity of enzymatic reaction increases with the ................. in substrate concentration up to a certain point until it approaches the maximum value.

Explanation

To answer the question, we need to understand the relationship between substrate concentration and the velocity of enzymatic reactions.

1. **Understanding Enzymatic Reactions**: Enzymes are biological catalysts that speed up chemical reactions. The rate at which an enzyme catalyzes a reaction can be influenced by various factors, one of which is the concentration of the substrate.

2. **Effect of Substrate Concentration**: As the concentration of the substrate increases, the velocity (or rate) of the enzymatic reaction also increases. This is because more substrate molecules are available to bind to the enzyme's active sites, leading to more frequent formation of enzyme-substrate complexes.

3. **Saturation Point**: However, this increase in reaction velocity does not continue indefinitely. There is a limit to how much the reaction rate can increase, known as the maximum velocity (Vmax). Once the substrate concentration reaches a certain level, all the active sites of the enzyme molecules become occupied (saturated).

...