4 – Digestion in the mouth

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. Question What happens when amylase is mixed with a starch solution? Hypothesis/Prediction Ifamylase 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. (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 Sugar test Starch test

4. 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

5. Conclusion 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 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 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.