Name _______________________________ Date____________________ Period ___
BACKGROUND INFORMATION: What is the body’s major site of digestion? If you answered the stomach, you missed it! The correct answer is the small intestine. Imagine a water hose 1 inch in diameter and 20 feet long. This is the overall size of your small intestine. Most digestion occurs in the first 10 inches, and the remaining length is used for absorbing nutrients.
Food is squirted into the small intestine through a valve connecting it to the stomach. Small quantities of semi-fluid, approximately 1 teaspoon per minute, are released into the small intestine and combined with fluids from the pancreas and the gall bladder.
The fluids from the pancreas neutralize the stomach acid and carry enzymes for digesting proteins, fats, sugars, and starches. Some proteins and starches are digested earlier in the gut while others are digested in the small intestine.
The brain tells the body how much enzyme of each type to secrete into the small intestine.
The gall bladder secretes bile into the first 10 inches of the small intestine. Bile works like a detergent to break fat globules into smaller droplets for digestion. The smaller droplet increases the surface area upon which the pancreatic fluid can act to begin the digestive process.
Digested food is absorbed in the walls of the small intestine as it moves through the intestine. The undigested food is not absorbed. It moves to the next part of the gut, the large intestine.
SAFETY: Wear eye protection and do not taste or smell any of the materials.
MATERIALS: Freezer bag, graduated cylinder, 3 drops food color, 25 mL vinegar, 25 mL oil,
25 mL baking soda solution, and 10 mL detergent
PROCEDURE:
1.
Add 25 mL of vinegar (representing acid from the stomach) and 3 drops of food color to the freezer bag.
2.
Measure 25 mL of oil. Pour the oil into the freezer bag and seal the bag. Mix gently. This mixture represents the liquefied food leaving the stomach and entering the small intestine.
Observe the bag. DESCRIBE and DRAW what you see.
The vinegar (representing acid from the stomach) makes the large fat globules [float or sink] to the [top or bottom] of the liquid. [Circle the correct answer]
MORE ON THE NEXT PAGE!

Name _______________________________ Date____________________ Period ___
3.
After you complete your observations in step 2, add 25 mL of baking soda solution to the freezer bag and seal the bag. Mix gently. The baking soda solution represents the fluid from the pancreas that is added to food as it enters the small intestine. Pancreatic fluids function to digest and neutralize the acidic liquefied food as it leaves the stomach. Observe the bag.
DESCRIBE and DRAW what you see.
The baking soda (pancreatic solution) helps [acidify or neutralize] the acid and [breakdown or decrease] large particles into smaller particles. [Circle the correct answer]
4.
Mix the contents of the bag again. Observe. What do you see? __________________________
____________________________________________________________________________________
5.
Bile is produced by the liver and stored in the gall bladder. The bile is secreted into the small intestine to break large droplets of fat molecules into smaller ones. This increases the surface area where fat-digesting enzymes work. Bile works like detergent on food entering the small intestine. Add 10 mL of detergent to the bag and seal the bag. Gently mix the contents.
OBSERVE. DESCRIBE and DRAW what you see.
The detergent (bile) breaks up the large ______ _______________ into even ________ ones.
CONCLUSION QUESTIONS:
1.
Pancreatic juices contain enzymes that digest starches, sugars, proteins and fats. Why are all of these enzymes needed in the small intestine?
Enzymes are needed to break down large particles of starches, sugars, proteins and fat into smaller particles thereby increasing the __________ ________ for absorption. Food gets
________________ in the small intestine.
2.
Bile works like a detergent to break oil into droplets that easily mix with the pancreatic fluids. Why is this important for the digestion of fats?
Large fat particles are broken into smaller ones to increase the surface area for
________________________.

Name _______________________________ Date____________________ Period ___
CLEAN UP: Throw the plastic bag in the trash can, rinse the graduated cylinder and clean up any spills.
BACKGROUND INFORMATION: The large intestine is where final digestion occurs. Up to 10 liters of food, drink, and secretions travel through the gut in a day, but only 1 liter or less will reach the large intestine. This liter is mostly plant fibers and water. There are no digestive enzymes in the large intestine; bacteria conduct the digestion occurring here. So why is gas produced? Gas is a waste product of the bacteria digesting high fiber foods.
These bacteria are necessary for our survival. They not only produce vitamins B and K,
they also maintain water balance in our large intestine. Without them, we would have diarrhea and become dehydrated.
Beano helps break down the complex sugars found in many foods, making them easier to digest so they don’t cause gas.
SAFETY: Wear eye protection and do not taste or smell any of the materials!
MATERIALS: Freezer bag, graduated cylinder, spoon, 1 spoonful of refried beans,
15 mL of water, glucose test strips, and Beano solution.
PROCEDURE:
1. Add 1 spoonful of refried beans to the freezer bag. Dilute the beans with 15 mL of
water. Seal the bag and mix the contents thoroughly.
2. After mixing, test the bean mixture for glucose using a glucose test strip. Check the
strip against the color chart on the glucose strip container to determine the amount of
glucose present. Is there glucose in the solution? ________________
If there is glucose present, how much is there? __________________ KEEP this test
strip to use again later in this learning experience.
3. Add 8-10 drops of Beano solution to the bean mixture in the bag. Mix thoroughly.
Beano contains an enzyme similar to an enzyme found in the gut. Wait 5 minutes and
then test the mixture for glucose using the reserved glucose test strip. Check the strip
against the color chart on the glucose test strip container to determine the amount of
glucose present. Is there glucose in the solution? _____________
If there is glucose present, how much is there? _______________
CONCLUSION QUESTIONS:
1.
What happens when Beano is mixed with the beans? (Hint: Think about what the test strip indicated!)
__________________ is produced.
2.
Why does Beano help prevent the production of gas? (Hint: Re-read the background!)

Name _______________________________ Date____________________ Period ___
3. Why do some antibiotics cause vitamin loss and diarrhea?
Some antibiotics _______ the bacteria in the large intestine thus there are not enough
bacteria to produce vitamin _____ and _____ and maintain a proper __________
balance.
CLEAN UP: Throw the plastic bag and used glucose test strip into the trash can. Rinse the graduated cylinder and return it and the Beano to the plastic bin. Clean up any spills on the table or in the plastic bin.