Question

11) A phospholipase hydrolyzes its substrate with a KM of 10 x 10-6 M and a Vmax of 7 x 10-6 g of substrate · mg enzyme-1 · s-1. In the presence of 30 µM of an inhibitor, the KM increases to 40 µM

Answer 1

It is about the effect of an inhibitor on the kinetic parameters (KM and Vmax) of a phospholipase enzyme, indicating a competitive inhibition and an increase in KM value.

Step-by-step explanation:

It is the effect of an inhibitor on the kinetic parameters of a phospholipase enzyme. Kinetic parameters like KM (Michaelis constant) and Vmax (maximum rate of reaction) are crucial in understanding how enzymes interact with their substrates and inhibitors. When the inhibitor is present, the KM value of the enzyme increases, implying a change in the affinity between the enzyme and its substrate.

The increase in KM in the presence of an inhibitor suggests a competitive inhibition mechanism, where the inhibitor competes with the substrate for binding to the active site of the enzyme. As a result, a higher substrate concentration is needed to reach half of the Vmax, hence the increase in KM. This concept is part of the Michaelis-Menten theory, which explains enzyme kinetics and helps to understand how enzymes are affected by factors like substrate concentration, enzyme concentration, and the presence of inhibitors.