1. Getting Started What are the major Functions of the digestive system?
Where does this breakdown occur?
Two types of food breakdown
Mechanical Breakdown: this is where food is physically broken into smaller pieces
Chemical Breakdown: This is where particles of food are broken down by chemicals

2. Why do We use Models?
We are not able to observe the actual process in a classroom setting.
In this model we will use vinegar, which is an acid, to simulate the chemicals in the stomach that contribute to chemical breakdown

3. SALI: Activity 14- “Breakdown”
On Your Lab
SALI: Activity 14- “Breakdown”
CQ: Why is it important to chew your food?

4. Lab Write up Independent Variable: Size of the antacid tablet
Dependent Variable: Time it takes to break down
Controlled Variables:
1.) Cups
2.) Graduated cylinder
3.) Amount of vinegar (5 mL)
Hypothesis: If food is (smaller, larger) then I think that the food will break down
(slower, faster) than food the opposite size.
Materials:
1.) Cups and SEPUP Tray
2.) Antacid tablets-effervescent
3.) Vinegar
4.) 25-mL graduated cylinder
5.) Paper Towels
6.) Goggles
7.) Stopwatch
Safety: “Waft” vinegar…it’s a strong odor.

5. Procedures:
1.) Place 1/4 of an antacid tablet (whole not broken) into cup A.
2.) Add 5mL of vinegar to cup A and record the time it takes to dissolve. Place the time in the data table below.
3.) Place 1/4 of a broken antacid tablet into cup B.
4.) Repeat step 2, but add it to cup B.
5.) Place 1/4 crushed (powdered) antacid tablet into cup C.
6.) Repeat steps 2 and 4, but add to cup C.

6. Total Time to Dissolve seconds (s)
Data Table:
Antacid Tablet
Total Time to Dissolve seconds (s)
Cup A
(whole 1/4 piece)
Cup B
(1/4 broken)
Cup C
(1/4 crushed/powder)

7. Graph your Data- Create a Bar Graph
What can you conclude from your Bar graph?

8. Conclusion
In a paragraph, summarize the procedures to the lab and include the data you collected, re-state your hypothesis (was it correct?), and give your final results. How does the size of your food affect the speed at which chemical breakdown occurs.
Give data to support your conclusion.

9. Closure 1. In your experiment, what variables did you keep the same?
2. Where there any variables (except for the one being tested that you could not keep the same?
3. What part of the digestive process was modeled by breaking the tablet?

10. Closure Questions
Based on your data, how does the size of your food affect the speed at which chemical breakdown occurs?
Where your conclusions based on qualitative or quantative data? Explain.