Enzyme Saturation and Reaction Rates
Enzymes are biological catalysts that play a crucial role in facilitating chemical reactions in living organisms. They are typically proteins that lower the activation energy of a reaction, allowing it to occur more rapidly. The activity of an enzyme can be affected by various factors, such as pH, temperature, and substrate concentration. This relationship can often be visualized by determining an enzyme's Michaelis-Menten kinetics.
Consider a hypothetical enzyme, Enzyme X, which catalyzes the conversion of Substrate A to Product B. During an experiment, it was observed that at low concentrations of Substrate A, the reaction rate increased dramatically with increasing substrate concentration. However, at high concentrations of Substrate A, the rate of increase plateaued and reached a maximum velocity (Vmax).
If the concentration of Substrate A is increased beyond a certain point and the reaction rate no longer increases, which of the following statements best explains this observation regarding Enzyme X?