An Enzyme Has a K_M of 20 µM and a V_max

Multiple Choice

An enzyme has a K_M of 20 µM and a V_max of 50 mmoles of product/minute/µg of enzyme. After exposure to an inhibitor and analysis on a Lineweaver-Burk plot the following values are obtained: -1/ K_M = - 0.05 liters/µmole and 1/ V_max = 0.04 (mmoles of product/minute/µg of enzyme) ^-1. What kind of inhibitor was used in the experiment and what data interpretation supports this conclusion?

A) noncompetitive inhibitor because the K_M has remained the same and the V_max has decreased
B) competitive inhibitor because the K_M has remained the same and the V_max has decreased
C) noncompetitive inhibitor because the K_M has increased and the V_max has decreased
D) competitive inhibitor because the K_M has increased and the V_max has decreased