Last semester, dr. lisenbee asked his instructional aides to carry out the experiments associated with this week's lab exercise to be sure that the reagents and materials functioned properly. when they completed exercise 2, the aides noted that ptu inhibited catechol oxidase at low concentrations of catechol. however, when the concentration of catechol was increased, ptu was not effective at inhibiting catechol oxidase. based on this information, what kind of inhibitor is ptu? (a) non-competitive(b) competitiv(c) feedback(d) cyclical