What does acid do to egg whites?

Procedure

1. Prepare 8 small test tubes (10 mL size), each with an equal-sized cube of hard-boiled egg white. Make sure the piece of egg white is small enough to fit inside the tube.

2. Prepare the tubes as follows:

tube 1 & 2 - 5 mL water

tube 3 & 4 - 5 mL pepsin

tube 5 & 6 - 5 mL water + 7 drops hydrochloric acid

tube 7 & 8 - 5 mL pepsin + 7 drops hydrochloric acid

3. Leave the odd numbered tubes at room temperature and place the even numbered tubes in the incubator at 37^oC.

4. Let the cubes sit overnight. Observe the cubes the next day and record your observations.

Questions

1. Why was egg white used? (contains the protein albumin)

2. Describe the appearance of the egg white in each tube.

3. Why was the experiment performed at two different temperatures? (shows the effect of humanbody on the process)

4. Describe and explain the effect, if any, of temperature.

5. Which test tube most closely resembles the conditions in the human digestive system? (tubewith pepsin + acid at 39^oC)

6. Do the liquids appear different in the end? Explain.

7. What specific effect is pepsin having on the egg white?(digesting into smaller proteins)