1. 4 – Digestion in the mouth
Explore mechanical and chemical digestion in the mouth.
Define the word enzyme
Bellwork (Engage)
What is digestion?
What other ways does your body digest besides chewing?
Getting Started (Have students chew a soup cracker and feel their throat as they swallow it. Have them let a cracker sit in their mouths without chewing)
Describe everything that happened to the cracker as you chewed and swallowed it. What happened when you didn’t chew it? (go over answers and discuss role of amylase in the mouth)
Objectives

2. Hypothesis/Prediction
Question
What happens when amylase is mixed with a starch solution?
Hypothesis/Prediction
If amylase is mixed with starch, then the starch will . . .________ because . . .________
Materials
Benedict’s, Lugol’s, amylase, water, starch, test tubes and racks, trays, toothpicks, pipettes, hot pots

3. 30 drops of starch solution
(Review safety tips p 16 and testing procedures for sugar and starch)
Procedure/Planning
Number the cups of the tray from 1-6
Add the items to the tray as show in the chart
Stir cups 3,4,5 & 6 with separate toothpicks and let sit 5 min
Test contents of cups 1,3 & 5 for sugar using 3 test tubes and Benedict’s solution
Test contents of cups 2,4 & 6 for starch using Lugol’s solution
Compare solutions to the control (cups 1 & 2) to determine presence of starch or sugar
Tray set up 1
30 drops of starch solution 3
30 drops of water
2 drops of amylase 5 2
30 drops of starch
solution 4 6
Sugar test
Starch test

4. Data Chemical Test Sugar Test Starch Test
Directions call for students to decide what words and labels to use for themselves. Most will never figure it out so give them the chart.
Data
(SS 4.1 p 41 TM) Substance being tested
Chemical Test
Starch Solution
Amylase and distilled water
Amylase and Starch Solution
Sugar Test 1 3 5
Starch Test 2 4 6

5. Conclusion Next question Reflection questions
Answer the original question
Restate the hypothesis
Include data and observations
Next question
Reflection questions
What is amylase?
What did the amylase do when you mixed it with the starch solution?
Why do you need to wait 5 minutes before you perform tests with the amylase?
For which nutrient did the starch solution test positive?
For which nutrient did the amylase test positive?
For which nutrient did the mixture of amylase and starch test positive?
Amylase is an enzyme. Based on what you observed, what is an enzyme?

6. Homework Vocabulary Important for later lessons
Read Spies – Into the System p 30 SG
Summarize the steps of digestion in the mouth using the vocabulary words. (You can use the summary boxes on pg 35 of TM)
Vocabulary
Saliva Amylase
Mechanical digestion Enzyme
Chemical digestion Epiglottis

7. Additional Homework Evaluation
Reflections question 4 pg 34 - Discuss the action of the epiglottis during swallowing.
Art- Create “flavor maps” that indicate where the taste receptors are located on the tongue.
Language- Write a paragraph explaining the phrase “you are what you eat.”
Evaluation
Lab worksheet/ lab report
Reflection questions
**Summary of digestion

8. Preparation for lesson 5 – p 36 TM
Critical to think and prepare ahead.
Eggs or egg alternative must be cooked/cut before hand. Can buy cooked eggs.
Tofu is easier to cut and observe than eggs
Artificial gastric juice and pepsin must be refrigerated or kept cold except during actual use. They break down quickly if not cooled. I suggest you mix them the morning of your inquiry.