Final answer:
An enzyme with higher substrate affinity reaches its maximum reaction rate (Vmax) more quickly because it binds the substrate more efficiently, leading to more rapid product formation until the enzyme active sites are saturated.
Step-by-step explanation:
Enzymatic activity and substrate concentration are closely linked in biochemical reactions. When a substrate has a higher affinity for an enzyme, it binds more readily and efficiently to the enzyme's active site. As a result, the rate of product formation increases because the enzyme is more effectively utilized. At lower substrate concentrations, the reaction rate increases in proportion to substrate concentration. However, beyond a certain point, known as Vmax (maximum velocity), all enzyme active sites are saturated with substrate, and increasing the substrate concentration further will not increase the reaction rate.
The Michaelis-Menten constant, or Km, is the substrate concentration at which the reaction rate is at half its maximum. A lower Km value indicates a higher affinity between an enzyme and its substrate, meaning that it takes less substrate to reach half of Vmax. At high substrate concentrations, enzymes operate at their maximum capacity. Thus, an enzyme with a higher affinity for a substrate will reach its Vmax at a lower substrate concentration compared to an enzyme with lower affinity.