You will use information on the World Wide Web to answer a series of questions.

EXERCISE 1: THE CHEMICALS OF NUTRITION

Before you heard of fats, proteins, and carbohydrates as the building blocks of life, you probably heard of them as types of food. In the first part of this exercise, you will look at the fat, protein, and carbohydrate contents of plants and animals--not to plan a healthy meal, but to explore the functions of these three types of molecules. In the second section, you will learn about vitamins and minerals--what foods contain them and why we need them.

Print out the worksheet below and use the links to answer the following questions.

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Name _____________________________________________________

Link and Think
The Chemicals of Nutrition

Most of the questions in this exercise can be answered using CNN's Food Pages. You will find the Our Specials menu running along the right side of the page. Each Specials page contains stories, links, and nutritional comparison data for each food category.

1. Find the Nutritional Comparison chart on the Specials page for each food type listed below. Use the chart to find specific foods in each category. Pick foods that have not been combined with other ingredients: whole grains and cuts of meat, for example, instead of bread, pasta, or luncheon meats. Find out how many grams of fat, protein, and carbohydrates each food contains (do not add fiber, though it is technically a carbohydrate). Using the sum of these weights, calculate the percentage of fat, protein, and carbohydrate in each of these foods (listed as F:P:C). Refer to section 2.1 in your book to learn more about the roles of these molecules, then answer these questions:

a.Which food in the table had the highest percentage of fat?
Why do you think this food is high in fat?
b. Which food in the table had the highest percentage of protein?
Why do you think this food is high in protein?
c. Which food in the table had the highest percentage of carbohydrates?
Why do you think this food is high in carbohydrates?

		Fat (grams)	Protein (grams)	Carbohydrate (grams)	F:P:C (percent)
EXAMPLE Fruit:banana		0.5	1	27.5	2:3:95
Fruit: __________
Vegetable: __________
Grain: __________
Meat: __________

2. Look at the pork by-products at the bottom of the Pork Nutritional Comparison Chart. Ignoring chitterlings (hog intestines), which organ has the most fat? Which has the most protein?

3. Take a look at the table of protein function in figure 2.3 on page 36 of Biology: The Web of Life. Which function does the protein of meats have? of milk?

Vitamins and Minerals

4. Look on the Fruit Nutritional Comparison Chart to find which fruit has the most vitamin C per serving? Is one serving enough to meet the recommended daily allowance (RDA) of 50 to 60 mg?

5. Calcium is found in dairy products, shellfish, and leafy green vegetables. Look on the Dairy Nutritional Comparison Chart to find how many cups of milk must you drink to have 1200 mg of calcium today? How many servings of low fat or skim (nonfat) yogurt would you need to eat?

6. What body systems need calcium to function properly? Take a look at the Quick Facts About Calcium and circle the answers that apply.

skeletal	muscular	digestive
circulatory	immune	nervous

7. Look on the Vegetable Nutritional Comparison Chart to find which vegetable has the highest iron content per calorie? How many servings of this vegetable would you need to eat to consume 15 mg of iron?

8. Certain foods should not be eaten in combination with iron-rich foods. What substances reduce absorption of iron? Read the Quick Facts About Iron and circle your answer(s).

black tea

bran

vitamin C

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Check your work here.

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 [Unit 1 Index] 

Learning Links:
Chapter 1 || Chapter 2 || Chapter 3 || Chapter 4 || Chapter 5

In the News || Link and Think || Spotlight on Careers || Teachers' Lounge

In the Community:
Chapter 1 || Chapter 2 || Chapter 3 || Chapter 4 || Chapter 5