Question

A drug, Drug X, is transported across the intestinal luminal membrane by a facilitated transporter. Which of the following statements is true about the transport process? 1. At high concentrations, the rate of transport of Drug X will achieve a maximum rate or Vmax. 2. The rate of Drug X transport will increase linearly with concentration from low to high concentrations. 3. The rate of transport of Drug X will be greater if its hydrophobicity were increased through chemical modification. 4. Concomitantly administered drugs will not reduce the rate of transport of Drug X. 5. Transport of Drug X across the intestinal luminal membrane will require energy.

Answer 1

1 When the carrier is saturated the rate of transport is maximal..This rate is referred to as Vmax is characteristic of a specific carrier and reflects the rate with which the carrier can flip between its two cnformational states.The activity of an enzyme is described by its Michaelis constant,which is the concentration of substrate at which it is workingat 50%of its maximum rate.Enzymes Other drugs or food may interact with the drug in question and reduce the rate of absorption.Enzymes with high metabolic capacity have Michaelis constants higher than substrate concentrations.+