Grade Level/Subject: Grades 5-6 Health: Digestion

Materials:

measuring cup jar water funnel spoon 5 filters

sugar iodine solution cornstarch dropper sugar test paper

Procedure:

1. Fill measuring cup with 240ml of water. Add 1 spoonful of sugar and 1 spoonful of cornstarch. Stir to mix.
2. Place the filters into the funnel, one filter inside the other. Fit the funnel on the top of the jar.
3. Pour the water mixture into the funnel. Be careful not to let any of the liquid spill over the top edge of the funnel.
4. Remove the funnel from the jar. Test the water in the jar with the sugar test paper. If sugar is present, the paper will change color. Record your observation.
5. Now test for starch. Use the dropper and carefully put 5 drops of iodine solution into the jar. If starch is present, the reddish-brown iodine will turn the water bluish-black. Record your observation.

Your results should be that you tested positive for sugar but negative for starch. You can explain to your class that sugar molecules are small and are able to pass through the filters but the starch molecules are larger and are unable to pass through. This experiment simulates the small intestine. The filters are a simulation of the villi found in the small intestine. The filters permit only small particles to pass through, just as walls of intestines permit only small molecules to pass through.

Make sure you get filters for use in a chemistry lab. Regular coffee filters will not work. (These allow the starch molecules to go through.)

Again, I found this experiment in the _Discover the Wonder_ series.

I also created a test that you may want to use after you have taught a mini unit on digestion. Here it is:

Choose from the word bank below to fill in the missing word(s).

1. You store energy as _.
2. _ control how quickly chemical reactions take place in the body.
3. Most of digestion occurs in the _ _.
4. The watery substance in your mouth is called _.
5. The breaking down of food into forms your body can use is called _.
6. Enzymes not only break down food but they also destroy some _.
7. The tiny, finger like structures that line the small intestine are called _.
8. _ gives people energy to keep warm, to grow and maintain cells, to move muscles, and so on.
9. Digest food molecules pass into the small intestine and leave through the villi into blood vessels as _.
10. Digestion begins in the _.
11. Food travels through the _ to the stomach.
12. _ juices enter into the stomach to begin breaking down food.

    Bonus Question - 5 pts.

13. Name two other organs that produce enzymes that aid in digestion. _ and _. (Not found in word bank.)

Word Bank

respiration small intestine nutrients saliva mouth digestion

esophagus bacteria gastric villi fat enzymes

Answers to the test:

1. fat
2. enzymes
3. small intestine
4. saliva
5. digestion
6. bacteria
7. villi
8. respiration
9. nutrients
10. mouth
11. esophagus
12. gastric
13. liver, pancreas

I hope that some of you are able to use this. My fifth graders really enjoyed learning about digestion.

If something is not clear, just email me.

Trish

"Teachers plant the seeds of the future."

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