Name _________________________Date _______ Class _______
Review Chapter 15: Section 3 – Food and Digestion
(Use pages 524 - 527 in your textbook)
Final Digestion and Absorption
Understanding Main Ideasigestion
Place a check mark in the correct column.
Answer the following questions.
9. What happens to the water contained in the materials that pass into the large intestine?
10. What is bile?
Building Vocabulary
Match each term with its function by writing the letter of the correct function in the right column on the
line beside the term in the left column.
____ 11. liver
a. stores bile
____ 12. gallbladder
b. tiny finger-shaped structure in the small intestine where absorption occurs.
____ 13. pancreas
c. solid wastes exit the body through this opening
____ 14. rectum
d. produces bile
____ 15. anus
e. structure in which waste material is compressed into solid form
____ 16. bile
f. produces enzymes that flow into the small intestine
____ 17. villus
g. breaks up fat molecules
Enrich Chapter 15: Section 3 – Food and Digestion
Lactose Intolerance
Lactose is a sugar found in milk and other dairy products. Lactose is broken down in the small
intestine by an enzyme called lactase. Almost all babies produce lactase in their digestive systems. As some
children become older, however, their digestive systems stop producing lactase.
People without the enzyme lactase are said to be lactose intolerant. Their digestive systems cannot
digest lactose. As a result, this sugar passes from the small intestine into the large intestine. A high
concentration of lactose in the large intestine causes water to move from the body into the large
intestine. At the same time, bacteria in the large intestine feed on the lactose. When the bacteria break down
this sugar, they produce various gases as waste. The combination of water and gases causes the large intestine
to swell, which results in cramps and diarrhea.
There is no cure for lactose intolerance, but there are ways that people who have this condition can
reduce their symptoms. One way is by avoiding dairy foods. Another way is by taking chewable tablets that
contain the enzyme lactase. These will allow a lactose-intolerant person to digest lactose
for a period of a few hours.
Answer the following questions on the lines provided.
1. A very small number of babies are lactose intolerant. Lactose intolerance is much more serious in a
baby than in an adult. Why do you think this is so?
2. Why does the large intestine swell when lactose-intolerant people consume foods with lactose?
3. Many grocery stores sell lactose-reduced milk. How do you think lactose reduced milk is made?
4. Susan can drink one glass of milk without having any symptoms, but if she drinks two glasses, she
gets painful cramps. Do you think her body produces lactase? Explain.
Key Terms
Answer the questions by writing the correct Key Term in the blanks. Use the circled letter in each term to
find the hidden Key Term. Then write a definition for the hidden Key Term.
***Some of the terms are from section 1. There will be a * before the # indicating this.
1.
What is the triangular organ that lies between the stomach and the first part of the small intestine
and produces enzymes that help break down starches, proteins, and fats?
___ ___ ___ ___ ___ ___ ___ ___
2.
What is a thick, slippery substance produced by the body that makes food move more easily through
the digestive system?
*3.
What nutrient acts as a helper molecule in many different chemical reactions within the body?
_____ _____ _____ _____ _____ _____ _____ _____
*4.
What is the process by which nutrient molecules pass through the wall of the digestive system into the
blood?
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____
*5.
What was developed by nutritionists to classify foods into six major groups and tell how many
servings from each group to eat?
____ ____ ____ ____
6.
_____ _____ _____ _____ _____
____ ____ ____ ____ ____ ____ ____
What is the organ that stores bile until it is needed in the small intestine?
____ ____ ____ ____ ____ ____ ____ ____ ____ ____ ____
7.
What is a protein that speeds up chemical reactions in the body?
_____ ______ ______ ______ ______ ______
*8.
What is a fat that is usually solid at room temperature and is found in meat and dairy products?
____ ____ ____ ____ ____ ____ ____ ____ ____
Key Term: ___ ___ ___ ___ ___ ___ ___ ___
Definition:
____ ____ ____
Practice Test
6. Waste materials are prepared for elimination from the body in the
a. small intestine.
b. rectum.
c. stomach. d. esophagus.
7. Bile is produced by the
a. liver.
b. gallbladder.
c. pancreas.
d. stomach.
8. Which of the following does NOT take place in the mouth?
a. An enzyme is added to food.
b. The teeth break food into smaller pieces.
c. Nutrients are absorbed into the bloodstream.
d. Both mechanical digestion and chemical digestion begin.
9. The protective substance that lines the stomach is called________________________.
10. Waves of contractions that move food one way through the digestive system are called______________
11. Most chemical digestion occurs in the ________________________.
12. Water is reabsorbed into the bloodstream in the________________________.
13. Absorption takes place in the
If the statement is true, write true. If it is false, change the underlined word to make the statement true.
_______________ 14. Absorption is the process of breaking food down into smaller molecules.
_______________ 15. Bile is stored in the pancreas.
_______________ 16. The epiglottis prevents food from entering the windpipe.
_______________ 17. Small structures that line the small intestine through which absorption occurs are called
peristalsis.
Interpreting Diagrams
Outline the path of food through the digestive system by writing the name of the correct organs on the
numbered lines in the diagram below.
18.
19.
20.
21.
22. Explain the difference between mechanical digestion and chemical digestion. Describe where each
process occurs.