How pH affects the activity of pepsin?

Pepsin functions best in acidic environments with a pH of 1.5 to 2. Pepsin denatures if the pH is more than 5.0.
Pepsin works better at temperature between 37°C and 42°C in humans.

With this information you can set up some experiments to show this.

Select 5 test tubes with water with their pH's ranging from 1 to 5.

Make sure they contain the same amount of water and kept at the same temperature.

Add the same amount of pepsin into each test tube.

Add the same size, shape and weight of a protein ( some kind of meat) to each tube.

Observe what is happening every 5 minutes and record the results.