Concept #1: The Lock and Key Model
Concept #2: The Induced Fit Model
Practice: Compare the two enzyme-catalyzed reaction diagrams below (i & ii) to determine which of the following is true.
a) The ES-complex in diagram (i) is #2 and in diagram (ii) is #3..
b) Catalyzed EA in diagram (i) is arrow #5 and in diagram (ii) is arrow #7.
c) Binding energy in diagram (i) is arrow #5 and in diagram (ii) is arrow #7.
d) Diagram (i) describes a “lock & key” model while (ii) describes more of an “induced fit” model.
Practice: What is a potential disadvantage for an enzyme having too high of an affinity for its substrate?
Practice: Select the best option that fills in the blanks appropriately in the order of their appearance.
The left graph depicts an energy diagram for the “_____________” model of enzyme-substrate specificity, whereas the right diagram depicts an energy diagram for the modern “_____________” model. In the lock & key model, the enzyme binds tightly and precisely to the “_____________.” In the induced fit model, the enzyme binds weakly to the “_____________” and then changes conformation to bind tightly to the “_____________.”