1. Chemical Digestion in the Stomach

2. Question:
Which solution: Water and pepsin, acid and pepsin, or acid will digest a raisin the fastest?

3. Hypothesis:
We think:
A mixture of HCl and pepsin will break down food the fastest.
HCl will break down food the second fastest.
Pepsin will break down food the slowest.

4. Materials:
3 test tubes
Gloves
Acid
Water
Pepsin

5. Procedure
Describe the experimental procedure that you followed.

6. Observations
Which solution digested food the fastest? Which solution digested food the slowest?
If you heated the solutions, did it change the rate of digestion? How?

7. Observations
Compare the raisin, meatball, and Cheeto that were placed in gastric juice (a mixture of HCl and Pepsin.)
Which food digested the most? Which food digested the least? Why do you think this is?

8. Observations

9. Conclusions Did the results match your hypothesis?
If no, why do you think that you reached an unexpected result?
What do your results prove about digestion in the stomach.
What would a good “follow-up” question be? What else would you like to know?