Download Model of Digestive Processes Lab

Model of Digestive Processes Lab.
Your digestive system is made up of multiple organs each of which has a separate function.
These functions are mechanical or chemical.
Mechanical processes include breaking food into smaller pieces or squeezing and rubbing of food by organs in the
system.
Chemical processes include changing the chemical make up of food and breaking food molecules into smaller
molecules.
When all your digestive system organs work together this results in the extraction of nutrients from many different
types of food.
The process begins in the mouth where the ____________ and _________________
mechanically break up food in the process called ______________________.
Chemical digestion also begins here with an enzyme in saliva called amylase which breaks down the long
carbohydrate molecules in bread and pasta into short carbohydrate molecules called sugars.
Activity #1
You can experience this yourself using a small piece of dry unsalted cracker given to you by your teacher.
Place the dry cracker on your tongue and note how it tastes before you wet it with your saliva or chew.
Chew the cracker and note how its taste changes as the enzyme in your saliva works.
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Activity #2
Materials
1 Cracker
1 Ziplock Bag
Water
Procedure
1. Break the cracker into small pieces and put them in the bag.
What type of digestive process does this represent? ____________________
2. Add the water to the bag and seal securely.
3. Take turns mashing the cracker with the water inside the bag. Describe what happens to the
cracker. Which processes in the digestive system is this like? Where would these processes
happen?
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Activity #3
The stomach contains a very powerful acid which begins the chemical digestion of meat. Enzymes including pepsin in
the stomach are also involved in the chemical breakdown of proteins in meat.
We will model this using vinegar as an acid and meat tenderizer which contains an enzyme to break down protein.
We will have three models, one with vinegar, one with meat tenderizer and one with both.
Hypothesis
Which of these models do you think will do the best job in breaking down the jerky? Why?
Materials
3 Small pieces of beef jerky
3 Ziploc Bags
Vinegar
Meat tenderizer solution
Vinegar and meat tenderizer solution
Procedure
1. Using scissors cut each piece of jerky into about 8 pieces and put the same number of pieces
into each bag.
What type of digestive process does this represent? ____________________
2. Add the vinegar to one bag and seal securely. LABEL this bag with a V, name for your group
and your class period number.
3. Add the meat tenderizer solution to one bag and seal securely. LABEL this bag with a MT,
name for your group and your class period number.
4. Add the vinegar and meat tenderizer solution to one bag and seal securely. LABEL this bag
with a V+MT, name for your group and your class period number.
5. Take turns mashing the jerky with the solutions inside the bag. Describe what happens to the
jerky in EACH bag. Which processes in the digestive system is this like? Where would these
processes happen?
6. Leave the bags in class with your teacher until your next science class.
7. When you get he bags back from you teacher observe them and record what you see. What
has happened to the jerky in EACH bag? Was your hypothesis correct? What does this tell
you about how your digestive system works?
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