Answer:
If the shape of ADA's active site is changed, ADA can no longer bind and neutralize the toxin.
Step-by-step explanation:
The active site of an enzyme is a specific region on the enzyme that binds to the substrate, which is the molecule the enzyme acts on. The active site is typically a cleft or pocket on the enzyme surface that is the right shape and size to accommodate the substrate. The shape of the active site is critical to the enzyme's function because it determines the specificity of the enzyme. The enzyme's active site is designed to bind to a specific substrate and catalyze a specific reaction. If the shape of the active site changes, it can no longer bind to the substrate effectively and the enzyme can no longer catalyze the reaction. In the case of ADA, this would mean that the enzyme can no longer bind and neutralize the toxin, as the active site is not able to recognize the toxin anymore.