pH and Enzyme Function

The purpose of this experiment is to investigate the effect of pH on an enzyme's ability to function properly.

1. Using the hole punch, punch out 15 disks of filter paper. Make sure they are all of uniform size.

2. Label 5 beakers "pH 3", "pH 5", "pH 7", "pH 9", and "pH 11". Pour 25 mL of each solution into the appropriate beaker.

3. Place a small sample of the prepared baker's yeast solution in a beaker and place the 15 disks into it. Allow the disks to soak in the solution for a few minutes.

4. Using forceps, take one of the disks out of the yeast solution and put it at the bottom of the beaker labeled "pH 3". When the disk makes contact with the bottom of the beaker, start timing. When the disk reaches the surface of the solution, stop timing. Record the time.

5. Remove the disk and rinse and dry the forceps.

6. Perform five trials for each pH.

7. Produce a graph of time vs. pH. Plot the average of the trials for each pH.