1. Lab Report- Mechanical and Chemical Digestion
Purpose: How does mechanical digestion affect the rate of chemical digestion?

2. Background Information
What is mechanical digestion?
Mechanical digestion is movement that breaks food down into smaller pieces.
Example: teeth crushing food in the mouth.
What is chemical digestion?
Chemical digestion is chemicals being added to change food into different substances.
Example: Saliva changes bread into starch and sugar.

3. Prediction
If we allow one antacid to remain whole, and crush the others into pieces, then
because

4. Plan- Materials 3 antacid tablets 10 ml of acetic acid (vinegar)
1 25 ml graduated cylinder
plastic stirring rod
Dixie cup
1 pair of scissors/plastic knife
Stopwatch

5. Plan- Procedure
1. ONE partner will take graduated cylinder to the vinegar station. Pour 10 ml of vinegar into the graduated cylinder.
2. Once you are sure your measurements are correct, carefully walk the graduated cylinder back to your seat and pour the 10 ml of vinegar into your dixie cup.
3. Start your timer.
4. Place 1 antacid tablet into the beaker with the vinegar.
5. Record observations every 30 seconds for a total of 3 minutes.

6. Plan- Procedure
7. Repeat steps 1-6 using an antacid tablet that you cut into 4 pieces. (Very carefully!)
8. Repeat steps 1-6 using an antacid tablet that you crush!

7. Data Collection Tablet Number Consistency Time (sec) Observations 1
Whole 30 60 90
120
150
180 2
4 pieces

8. Data Collection Tablet Number Consistency Time (sec) Observations 3
Crushed 30 60 90
120
150
180

9. Conclusions NO GRAPH REQUIRED!
Do you see any patterns or trends in your data? If so, what are they?
NO GRAPH REQUIRED!

10. Claims and Evidence
What is the answer to your prediction question? How does mechanical digestion affect the rate of chemical digestion?
What data do you have that supports your answer? Give specific examples.

11. Reflection What did you learn from this lab?
Discuss any errors or potential errors.
If you were asked to do this lab again, what would you do different?

12. WRAP-UP All trash should be thrown into trash can-
ONE Dixie cup, ONE stir stick, etc.
Wipe work area down with a damp paper towel. I should not see any crumbs on trash on tables
Place stopwatch, safety glasses, scissors, etc. and items for next class (1 cup, 1 stir stick) back into basket