Answer:
1. The range of pH used in the experiment was 5 to 12.
The range of temperature used was 30°C to 90°C.
2. Being protein in nature, enzymes work efficiently in narrow range of pH and temperature. They often show bell-shaped curve when enzyme activity is plotted against pH or temperature.
Increase in temperature increases the enzymatic activity up to a certain levels after which enzyme gets denatured and its activity reduces rapidly.
Similarly, pH also effects the activity of enzyme. Few enzymes work best in acidic pH (for example pepsin) while other work best in alkaline pH (for example digestive enzymes of pancreas and small intestine). pH other than the specific range changes the shape of the enzyme and thus reduces the activity of the enzyme.
Now, graph 1 shows the effects of pH on the enzymatic activity of protease enzyme. It shows the maximum activity at pH = 10 (alkaline) and lowest activity at pH = 5 (acidic). Hence, it works efficiently in basic or alkaline medium (within a range of 8-12).
Similarly, graph 2 shows the effects of temperature on the enzymatic activity of protease enzyme. It shows that enzyme works efficiently in the range of 50° C to 70° C with highest efficiency at 60° C.
3. Yes, the protease would be useful as it has maximum efficiency at pH = 10 i.e. basic and at 60° C (hot water).