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Examining Nutrition

Investigation 3 – Lab

Back to Investigation 3

BE PREPARED

Supplies and Equipment:

Class Materials:

1 5 lb bag of sugar or 350 g
1 food scoop

Group Materials:

1 triple beam balance
1 weigh dish
1 400 ml beaker
1 lab scoop
6 test tubes
1 test tube rack
1 food container with a nutrition label or a nutrition label from the Investigation Three Supplement Pages (Included below)
1 piece of masking tape, approximately 30 cm in length
Colored pencils or crayons (optional)

Individual Materials:

1 Student Data Record
1 Calculator

Teacher Preparation:

1. Make one copy of the nutrition labels provided at the end of this investigation. Cut the labels apart. (Optional: Provide empty containers of food items with nutrition labels. Each item should contain at least 10 grams of sugar and be from a different food group or category. The labels should contain the information for analysis during the Post-Lab of this investigation such as %DV total carbohydrates, an indication of whether sugar, fiber or other carbohydrates are in the food, serving size, and the weight or volume of the food.)

Note: If the nutrition labels from other foods are used, keep in mind that dry beans are considered part of the vegetables group and the meat and beans group. Also note that oil packaged separately, such as vegetable, olive, or canola oil, are included in the oils group.

2. For each group, fill a 400 ml beaker with sugar.

3. For each group, insert six test tubes into a test tube rack.

4. Place the materials each group will need at a distribution point with the exception of the five nutrition labels or five food containers.

5. Separate the class into five cooperative groups.

Instruction:

1. Instruct each student group to obtain the following necessary materials from the distribution point: One (1) triple beam balance, one (1) weigh dish, one (1) 400 ml beaker filled with sugar, one (1) test tube rack, six (6) test tubes, and one (1) piece of masking tape approximately 30 cm in length. Optional: one (1) pack of colored pencils or crayons.

GET FOCUSED

Investigation Three introduces students to the important class of nutrients, carbohydrates.

Triple Beam Balance Review (click to enlarge)

INVESTIGATE

Trial 1

In this Trial, students will determine the total carbohydrate content of various food or beverage items. Each group will be given a different “food item” (For the purposes of this Investigation, either an empty food container with a nutrition label or a nutrition label from above will be referred to as a “food item.”

Students will locate the amount of total carbohydrates contained in their item on its nutrition label and use the triple beam balance and sugar to measure the mass of total carbohydrates in the item. In this Trial, sugar will be used to represent the total carbohydrates in the food. The groups will then compare the total carbohydrates in their item to the total carbohydrate content in the other groups’ items. The passages that follow are provided to assist with the direction of the students as they conduct their experiment. The question students will investigate in this experiment is:

How many carbohydrates are in my foods and beverages?

a. Explain to students that they will determine the amount of total carbohydrates contained in one of five food and/or beverage items.

b. Announce the name of each of the “food items” to the class. Ask students to record the names of the “food items” in their table in Problem 2a of their Student Data Record.

c. Assign each group one “food item” that they will investigate. Students should indicate their “food item” by circling their item in the table and recording the name in Problem 2b of their Student Data Record.

d. Distribute one “food item” to each table and direct students to complete the nutrition label in Problem 2d for their specific item.

e. Explain that students will use the information on their nutrition label to measure the mass of the total carbohydrates contained in their “food item.” In order to do this, students will use sugar to represent total carbohydrates and the triple beam balance to obtain the mass of the total carbohydrates found in their “food item.”

Remind students that Use and Operation of a Triple Beam Balance is one of the tools from their Procedural Toolbox. Encourage students to recall the steps they need to perform in order to use the triple beam balance to measure the mass of a substance.
If necessary, direct student groups to equilibrate their triple beam balance before starting their experiment. Tell them they can refer to the directions for Triple Beam Balance Equilibration in their Procedural Toolbox if they wish.
After student groups have equilibrated their triple beam balance, remind them that they must obtain the mass of total carbohydrates in their item. If students need assistance in performing this task, either refer them to the directions in their Procedural Toolbox for Measuring Mass Using a Container or guide them through the process using the instructions that follow.

f. Direct students to use the length of masking tape and a pencil to label the set of test tubes as “Total Carbohydrates.”

g. Instruct students to pour the sugar carefully from the weigh dish into the test tubes. Tell them to fold the weigh dish so the sugar pours from one corner of the dish (see illustration above). Explain that they should fill the first test tube, then continue to fill additional test tubes until the weigh dish is empty.

h. Encourage students to illustrate the amount of sugar contained in their item by filling in the drawing in Problem 2j to match their test tubes.

i. Students should record the data they collected for their item into the table in problem 2a. j. Ask students: How does your item compare to the other groups’ items? • Direct students to visit the other groups’ tables and observe the amount of sugar measured out by each group for their item. • Once all student groups have rotated through the other four tables, instruct each student group to verbally present the serving size, mass, %DV, and food group or category for the amount of carbohydrates in each of these items to the class. Students should record the data in their Table in Problem 2a in their Student Data Records as it is presented.

Trial 2

During this Trial, students will determine the sugar content of their “food item.” Each group will use the same food item from Trial 1. Students will locate the amount of sugars contained in their item on its nutrition label and use the triple beam balance and sugar to measure the mass of sugars in the item. The question students will investigate in this experiment is:

How much sugar is in my foods and beverages?

a. Explain to students that they will determine the amount of sugars contained in their food or beverage item from Trial 1. Remind students that sugars are one type of carbohydrate.

b. Explain that students will use the information on their nutrition label to measure the mass of the sugars contained in their “food item.” In order to do this, students will use sugar and the triple beam balance to obtain the mass of the sugars found in their “food item.”

• Remind students that Use and Operation of a Triple Beam Balance is one of the tools from their Procedural Toolbox.

• Encourage students to recall the steps they need to perform in order to use the triple beam balance to measure the mass of a substance.

c. Direct students to use the length of masking tape and a pencil to label the set of test tubes as “Sugars.”

d. Once students have obtained the mass of sugars in their “food item,” instruct them to pour the sugar carefully from the weigh dish into the test tubes. Tell them to fold the weigh dish so the sugar pours from one corner of the dish. Explain that should they fill the first test tube, they should continue to fill additional test tubes until the weigh dish is empty.

e. Encourage students to illustrate the amount of sugar contained in their item by filling in the drawing in Problem 3j in their Student Data Records to match their test tubes.

f. Students will compare the drawings of the other groups and complete a table that compares the sugars contained in food items during PostLab.