Lesson 6 Diffusion and Active Transport

1. Lesson 6 Diffusion and Active Transport • Ojectives • Use models to show the spread of items through a membrane • Define diffusion • Explain the difference between diffusion and active transport and indicate why both are necessary • Summarize the digestive process in the small intestine • Bellwork(Spray air freshener before students arrive) • How does the fragrance of flowers reach your nose? • Can odors pass through solids? Explain. • (Pass around a balloon with anise seeds in one and anise extract in the other) • Why is the smell stronger in the balloon with the extract? • (Introduce the word “diffusion” but don’t define yet)

2. Review safety tips on pg42. Be aware of any latex allergies Problem Which solution, sugar or starch, can pass through a membrane? Hypothesis If a _________ solution is placed inside a membrane then it . . ._________ because . . .______________ Materials 2 graduated cylinders, beaker, dialysis tubing, string, 2 test tubes, Benedict’s, Lugols, hot pot, pipette, sugar solution, starch solution, water

3. Procedure • Label one test tube “sugar” and one “starch” • Use string to tie off one end of the tubing • Use a graduated cylinder to add 13 mL of each solution to the tubing • Rinse the outside of the tubing and place in the correct test tube • Add 8 mL of water to each test tube on the outside of the tubing • After sitting for 15 minutes remove the tubing (reading activity) • Add 8 drops of Benedict’s to the sugar test tube and heat for 1 min • Add 10 drops of Lugol’s to the starch test tube Data/Drawings • (I usually run off Student Sheet 6.1 on pages 66-67 in the TM. ) Students should: • choose between the choices in parentheses, • -complete the drawings using dots and arrows as instructed, • -answer the questions.

4. Conclusion • Use the word diffusion to answer the original question • Restate the hypothesis • Use test results to support conclusion • Reflecting on What You’ve Done p 45 in SG • Complete the student sheet • In terms of diffusion, what would happen if a bottle of food coloring was dropped into a pool? • Explain how the liver, pancreas and gall bladder aid in digestion in the small intestines (picture on pg 45). (answer in Spies reading p 48-49 or cover it in teacher notes) Next question

5. Vocabulary Diffusion Active transport Liver Bile Gall bladder Pancreas Selectively permeable

6. Readings • Diffusion and Active Transport: Getting From Here to There pg 46-47 in SG • Why are active and passive transport both important in the absorption of digested nutrients from the small intestine into the bloodstream? • What is the energy called that allows active transport to occur? • Spies-The Long and Winding Tube pg 48-49 in SG • What is the pyloric sphincter and where is it located? • What is the function of the pancreas and how much pancreatic juice is secreted every day? • What is secreted by the gall bladder and what is its function? • When digestion is finally complete, what has become of the pizza? Extensions p63 #2, 3, 4 These could be some of your options if you do a homework sheet for the week.

7. Teacher Prep pg 65 TM Borrow a digital balance from 6th or 8th grade AMSTI kits or contact your specialist to borrow one for a few days. Of course, you can always use an “old fashioned” triple beam balance as well. Must make 16 balls of clay that have the exact same mass Unit Assessment Lesson Eight is a unit assessment. Consider running off student sheet 7.1, p 78 in the TM, and distribute it now so students can be working on it to get ready for the assessment. Consider a review day to go over these questions