The MTT or TS assays measure the purple color produced by formazan, which correlates to the reducing ability of these substances. The steady-state approximation was used for the Briggs-Haldane equation governing their behavior, a slightly different take from the double reciprocal Lineweaver-Burk and (*) Michaelis-Menten equations that govern their kinetics. One proposed mechanism for these substances is the "induced fit model," and another suggests a lock-and-key fit with their substrates. For 10 points, name this class of substances that are inhibited competitively and allosterically, a class of biological catalysts 
The MTT or TS assays measure the purple color produced by formazan, which correlates to the reducing ability of these substances. The steady-state approximation was used for the Briggs-Haldane equation governing their behavior, a slightly different take from the double reciprocal Lineweaver-Burk and (*) Michaelis-Menten equations that govern their kinetics. One proposed mechanism for these substances is the "induced fit model," and another suggests a lock-and-key fit with their substrates. For 10 points, name this class of substances that are inhibited competitively and allosterically, a class of biological catalysts that includes amylase.
The MTT or TS assays measure the purple color produced by formazan, which correlates to the reducing ability of these substances.
{enzymes} [accept {E1} on the first clue, but prompt on it afterwards]