Answer:
The enzyme predicted its three-dimensional structure, making it impossible for its active site to match the substrate needed to carry out its biological reaction.
Step-by-step explanation:
If pH or temperature disables enzyme functionality, it means that the enzyme has been denatured and has lost its three-dimensional structure. In this way the enzyme became deformed and its active site completely changed its shape. As you may know the active site of the enzymes is the perfect fit for a substrate type, if the enzyme becomes deformed the active site will also be deformed and will not be able to fit with the substrate, in this case the enzymatic reaction is impossible to happen.