1. Interest Grabber Good Food Sense
Section 38-1
Good Food Sense
Nutrients are molecules that provide the body with energy and materials for growth. Three kinds of nutrients you eat are called fats, proteins, and carbohydrates—terms you may have already heard. Think about what they may mean.
1. Write a brief description of what you think fats, proteins, and carbohydrates are.
2. Which of these three nutrients do you think should make up the largest part of your diet? Which should make up the smallest part? Arrange the three nutrients in order starting from the one that you should eat the most to the one that you should eat the least.
3. Why might it be unwise to eat too much of the nutrient you listed last?

2. Section Outline 38–1 Food and Nutrition A. Food and Energy
B. Nutrients
1. Water
2. Carbohydrates
3. Fats
4. Proteins
5. Vitamins
6. Minerals
C. Nutrition and a Balanced Diet

3. Concept Map Nutrients Section 38-1 include Carbohydrates Fats Minerals
Proteins
Vitamins
include
are made of
are made using
include
include
Simple
Complex
Amino acids
Calcium
Iron
Fatty Acids
Glycerol
such as
such as
Sugars
Starches
Fat-soluble
Water-soluble

4. Figure 38–6 Types of Vitamins
Section 38-1
Vitamin
A (retinol)
D (calciferol)
E (tocopherol) K
B1 (thiamine)
B2 (riboflavin)
Sources
Yellow, orange, and dark green vegetables; dairy products
Fish oils, eggs; made by skin when exposed to sunlight; added to dairy products
Green leafy vegetables, seeds, vegetable oils
Green leafy vegetables; made by bacteria that live in human intestine
Whole grains, pork, legumes, milk
Dairy products, meats, vegetables, whole-grain cereal
Function
Important for growth of skin cells; important for night vision
Promotes bone growth; increases calcium and phosphorus absorption
Antioxidant; prevents cellular damage
Needed for normal blood clotting
Normal metabolism of carbohydrates
Normal growth; part of electron transport chain; energy metabolism

5. Figure 38–6 Types of Vitamins
Section 38-1
Vitamin
Niacin
B6 (pyridoxine)
Pantothenic acid
Folic acid
B12 (cyanocobalamin)
Sources
Liver, milk, whole grains, nuts, meats, legumes
Whole grains, meats, vegetables
Meats, dairy, whole grains
Legumes, nuts, green leafy vegetables, oranges, broccoli, peas, fortified bread and cereal
Meats, eggs, dairy products, enriched cereals
Function
Important in energy metabolism
Important for amino acid metabolism
Needed for energy metabolism
Coenzyme involved in nucleic acid metabolism; prevents neural-tube defects in developing fetuses
Coenzyme in nucleic acid metabolism; maturation of red blood cells

6. Figure 38–6 Types of Vitamins
Section 38-1
Vitamin
C (ascorbic acid)
Biotin
Choline
Sources
Citrus fruits, tomatoes, red or green peppers, broccoli, cabbage, strawberries
Legumes, vegetables, meat
Egg yolk, liver, grains, legumes
Function
Maintenance of cartilage and bone; antioxidant; improves iron absorption; important for healthy gums, tissue repair, and wound healing
Coenzyme in synthesis of fat; glycogen formation; amino acid metabolism
Required for phospholipids and neurotransmitters

7. Figure 38–7 Types of Minerals
Section 38-1
Mineral
Calcium
Phosphorus
Potassium
Chlorine
Sodium
Magnesium
Iron
Fluorine
Iodine
Zinc
Sources
Diary products; salmon; sardines; kale; tofu; collard greens; legumes
Dairy products; meats; poultry; grains
Meats; dairy products; many fruits and vegetables; grains
Table salt; processed foods
Whole grains; green leafy vegetables
Meats; eggs; legumes; whole grains; green leafy vegetables; dried fruit
Fluoridated drinking water; tea; seafood
Seafood; dairy products; iodized salt
Meats; seafood; grains
Function
Bone and tooth formation; blood clotting; nerve and muscle function
Bone and tooth formation; acid-base balance
Acid-base balance; body water balance; nerve function
Acid-base balance; formation of gastric juice
Activation of enzymes in protein synthesis
Component of hemoglobin and of electron carriers used in energy metabolism
Maintenance of tooth structure; maintenance of bone structure
Component of thyroid hormones
Component of certain digestive enzymes

8. Figure 38–8 Food Guide Pyramid
Section 38-1
Fats, Oils, and Sweets (use sparingly)
Soft drinks, candy, ice cream, mayonnaise, and other foods in this group have relatively few valuable nutrients.
Milk, Yogurt, and Cheese Group
(2-3 Servings)
Milk and other dairy products are rich in proteins, carbohydrates, vitamins, and minerals.
Meat, Poultry, Fish, Dry Beans, Eggs, and Nut Group
(2-3 servings)
These foods are high in protein. They also supply vitamins and minerals.
Vegetable Group
(3-5 servings)
Vegetables are a low-fat source of carbohydrates, fiber, vitamins, and minerals.
Fruit Group
(2-4 servings)
Fruits are good sources of carbohydrates, fiber, vitamins and water.
Bread, Cereal, Rice and Pasta Group
(6-11 servings)
The foods at the base of the pyramid are rich in complex carbohydrates and also provide proteins, fiber, vitamins, and some minerals.
Fats
Sugars

9. Interest Grabber Dinner Is Served
Section 38-2
Dinner Is Served
Remember the last time you sat down to a dinner of your favorite foods? Recall everything that you did before you swallowed your first bite.
1. Why do you cut up your food?
2. What role do your teeth play in eating?
3. Saliva is the fluid that is found in your mouth. What role do you think it plays in eating?

10. Section Outline 38–2 The Process of Digestion A. The Mouth 1. Teeth
2. Saliva
B. The Esophagus
C. The Stomach
1. Chemical Digestion
2. Mechanical Digestion
D. The Small Intestine
Accessory Structures of Digestion
E. Absorption in the Small Intestine
F. The Large Intestine
G. Digestive System Disorders

11. The Digestive Enzymes Section 38-2 Site Mouth Stomach
Small intestine (from pancreas)
Small intestine
Enzyme
Role in Digestion
Salivary amylase
Pepsin
Amylase
Trypsin
Lipase
Maltase, sucrase, lactase
Peptidase
Breaks down starches into disaccharides
Breaks down proteins into large peptides
Continues the breakdown of starch
Continues the breakdown of protein
Breaks down fat
Breaks down remaining disaccharides into monosaccharides
Breaks down dipeptides into amino acids.

12. Figure 38–10 The Digestive System
Section 38-2
Mouth
Salivary glands
Stomach
Pancreas (behind stomach)
Large intestine
Small intestine
Rectum
Gallbladder (behind liver)
Liver
Esophagus
Pharynx

13. Figure 38–13 The Liver and the Pancreas
Section 38-2
Liver
Gallbladder
Duodenum
Bile duct
Pancreas
Pancreatic duct
To rest of small intestine

14. Figure 38–14 The Small Intestine
Section 38-2
Small Intestine
Villus
Circular folds
Villi
Epithelial cells
Capillaries
Lacteal
Vein
Artery

15. Interest Grabber Your Body’s Filter
Section 38-3
Your Body’s Filter
Have you ever seen a water-purification system attached to a faucet? This system removes impurities from the water such as arsenic or other chemicals that can be harmful to people. As water passes through the filters contained in the system, the impurities are trapped on the surface of the filters. Eventually, the water that comes out of this purifier is free of the impurities.
1. Your body has its own system for filtering blood. Why might the blood in your body need to be filtered?
2. What organ(s) do you think filters your blood?
3. How do you think the filtered materials leave your body?

16. Section Outline 38–3 The Excretory System
A. Functions of the Excretory System
B. The Kidneys
1. Kidney Structure
2. Filtration
3. Reabsorption
4. Kidney Stones
C. Control of Kidney Function
D. Homeostasis by Machine

17. The Urinary System Section 38-3 Artery Vein Kidney (Cross Section)
Cortex
Medulla
Ureter
Urinary bladder
Urethra

18. Figure 38–17 Structure of the Kidneys
Section 38-3
Kidney
Nephron
Cortex
Medulla
Renal artery
Renal vein
Ureter
To the bladder
Bowman’s capsule
Glomerulus
Capillaries
Collecting duct
To the ureter
Loop of Henle
Artery
Vein

19. The Nephron Reabsorption Filtration Section 38-3
As the filtrate flows through the renal tubule, most of the water and nutrients are reabsorbed into the blood. The concentrated fluid that remains is called urine.
Filtration
Most filtration occurs in the glomerulus. Blood pressure forces water, salt, glucose, amino acids, and urea into Bowman’s capsule. Proteins and blood cells are too large to cross the membrane; they remain in the blood. The fluid that enters the renal tubules is called the filtrate.

20. Figure 38–19 Kidney Dialysis
Section 38-3
Blood in tubing flows through dialysis fluid
Blood pump
Vein
Artery
Shunt
Used dialysis fluid
Air detector
Dialysis machine
Fresh dialysis fluid
Compressed air

21. Click a hyperlink to choose a video. Human Digestion Kidney Function
Videos
Click a hyperlink to choose a video.
Human Digestion
Kidney Function
Video Contents

22. Click the image to play the video segment.
Human Digestion
Click the image to play the video segment.
Video 1

23. Click the image to play the video segment.
Kidney Function
Click the image to play the video segment.
Video 2

24. Go Online Interactive test
For links on nutrition, go to and enter the Web Code as follows: cbn-0381.
For links on digestion, go to and enter the Web Code as follows: cbn-0382.
For links on the excretory system, go to and enter the Web Code as follows: cbn-0383.
Internet

25. Interest Grabber Answers
1. Write a brief description of what you think fats, proteins, and carbohydrates are.
Accept all reasonable descriptions. You may wish to have students revisit their descriptions after completing this section.
2. Which of these three nutrients do you think should make up the largest part of your diet? Which should make up the smallest part? Arrange the three nutrients in order starting from the one that you should eat the most to the one that you should eat the least.
Carbohydrate, protein, fat
3. Why might it be unwise to eat too much of the nutrient you listed last?
Possible answer: The body needs only small amounts of fats; fats contain more Calories than the other nutrients do.
Section 1 Answers

26. Interest Grabber Answers
1. Why do you cut up your food?
To make pieces small enough to fit in the mouth
2. What role do your teeth play in eating?
They crush the food so it is small enough to be swallowed.
3. Saliva is the fluid that is found in your mouth. What role do you think it plays in eating?
Students will likely say that it moistens the food so it is easier to swallow. Students may also be aware that saliva contains a digestive enzyme.
Section 2 Answers

27. Interest Grabber Answers
1. Your body has its own system for filtering blood. Why might the blood in your body need to be filtered?
In order to remove from the blood any impurities that could be harmful
2. What organ(s) do you think filters your blood?
Possible answer: kidneys
3. How do you think the filtered materials leave your body?
Possible answer: as urine
Section 3 Answers

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