Temperature and pH vs Enzyme functionality
I think these two graphs explain it very well.
Temperature vs Enzyme activity:
As the temperature increases, enzymes work faster until they reach an optimum temperature. This temperature changes in different types of enzymes. However, if the temperature increases, enzymes start to denature and stop functioning.
pH vs Enzyme activity
Enzymes work best at certain pH. For this enzyme, it works best at 8pH and most work best when the pH is neutral (7). However, when the solution becomes too acidic or basic, the enzyme functionality decreases.