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Discovering Chemical Elements in Food (0 Favorites)

PROJECT in Molecular Formula, Molecular Structure, Measurements, Significant Figures, Molecular Structure , Saturated vs. Unsaturated. Last updated July 23, 2021.


Summary

In this project, students will analyze nutrition labels of some of the foods and drinks that they recently consumed. They will identify which type of macromolecule (carbohydrates, lipids, proteins) is mainly supplied by the item and they will compare their consumption with the daily recommended intake for that type of macromolecule. Students will also investigate salt and added sugar as well as vitamins and minerals in the item. Finally, students will present their findings through short, spoken messages that are recorded and presented through a QR code. These can become a source of information for the school community at large upon completion of the project.

Grade Level

High School or Middle School

NGSS Alignment

This project will help prepare your students to meet the performance expectations in the following standards:

  • HS-PS1-7: Use mathematical representations to support the claim that atoms, and therefore mass, are conserved during a chemical reaction.
  • HS-LS1-7: Use a model to illustrate that cellular respiration is a chemical process whereby the bonds of food molecules and oxygen molecules are broken and the bonds in new compounds are formed resulting in a net transfer of energy.
  • MS-LS1-7: Develop a model to describe how food is rearranged through chemical reactions forming new molecules that support growth and/or release energy as this matter moves through an organism.
  • Scientific and Engineering Practices:
    • Using Mathematics and Computational Thinking
    • Analyzing and Interpreting Data
    • Obtaining, Evaluating, and Communicating Information
  • Cross-Cutting Concepts:
    • Energy and matter: Flows, cycles, and conservation. Tracking fluxes of energy and matter into, out of, and within systems helps one understand the systems’ possibilities and limitations.

Objectives

By the end of this project, students should be able to:

  • Identify and analyze readily available information to calculate the percent of the daily recommended calories for (proteins, fats, carbs) in a sample of food.
  • Calculate the percentage of the recommended dietary allowance (RDA) of added sugar in a food or drink.
  • Calculate the percentage of the recommended dietary allowance (RDA) of sodium in a food or drink.
  • Describe which chemical elements make up the molecules in the food item.
  • Evaluate beneficial and harmful effects and healthy limits of mineral and vitamins.
  • Explain how the food we eat determines and makes the composition of our bodies.

Chemistry Topics

This project supports students’ understanding of:

  • Molecular Structure
  • Molecular Formula
  • Organic Chemistry
  • Saturated vs. unsaturated
  • Monomers
  • Polymers
  • Measurements
  • Unit Conversions
  • Significant Figures

Time

Teacher Preparation: 30 - 60 minutes
Lesson: 100 - 300 minutes (Note: the project can be adapted to accommodate limited or extended time or student accommodations.)

Materials

Safety

  • No specific safety precautions need to be observed for this project.

Teacher Notes

  • This project was originally developed for students in a modified chemistry class, as a summative assessment at the end of a unit called “Food: Matter and Energy for Life”.
  • Most of the students in this modified chemistry class are challenged by reading comprehension and analyzing numbers. In my experience, students respond to this project very well because it’s centered around food and they can choose their favorite foods to use.
  • The project heavily relies on synthesizing information from lessons, the governments’ website with Dietary Guidelines and nutrition labels and as such it reinforces several anchor standards of the Common Core Reading Standards.
  • Upon completion of this unit, students have hands-on experience utilizing readily available information to inform their dietary choices.
  • The materials and pacing can easily be adapted for students with a stronger aptitude for math and reading comprehension.
  • I end the unit with a slideshow that provides an overview of the macromolecules that are part of a healthy diet and the ways in which our bodies gain energy from each through cellular respiration. This slideshow (available to download) forms the start of the project.
  • This can be done in one lesson, or it can be spread out over three lessons.  I do one lesson for each macromolecule, followed by other activities, which works best for my class.
  • Alongside these lessons, students read two articles from ChemMatters magazine: “The Protein Myth” and “Shaking out the Facts about Salt”. As a class, we go through the statements provided in the reading guides (copied from the teacher guide supplied by ChemMatters, with minor modifications) for these articles and we discuss what we know/think before reading.
  • Upon reading, students go through the statements again, based on what the text says. Students then start the project, “Discovering Chemical Elements in Food”. This project is designed to be completed individually by students, but can easily be adjusted to be done in small groups.
  • Teaching Tips:
    • When using the macromolecule (Carbs, Fats and Proteins) PowerPoint presentation, it is recommended to delete the calorie and mass ranges on slides 7, 13 and 19 so that the underlying calculations can be practiced with students ahead of the project.
    • Provide a copy of each ChemMatters article, and its associated reading guide to each student. Answer keys are available for teacher reference as well.
    • For reference you can access the full Dietary Guidelines for Americans online. I created a shortened version (available for download) to accommodate my students, of the recommendations that apply to adolescents. The guidelines are revised every 5 years.
    • Provide student handout to each student. The handout first includes several questions to help guide students during the PowerPoint presentation, followed by the main components of the project, and an evaluation rubric at the end. I typically provide students with rubrics at the beginning of a project like this. I also recommend having a formative assessment conference with students at least once to discuss their progress.
    • Note: the project is most straightforward when students chose foods or drinks with nutritional labels. It is however entirely possible to complete this project with foods that are prepared from scratch, or using a piece of fruit. The handout provides resources to find all the relevant nutritional information. It adds an extra level of complexity. Many take-out places provide detailed nutritional information for each of their menu items on their websites; this is another way for students to practice identifying and analyzing relevant information.
    • Note on calculating the percentage of RDA of added sugars: Most nutrition labels will not state this simply because there is no recommended amount of added sugars. The Dietary Guidelines suggest that the total amount of added sugars does not exceed 10% of one’s daily Caloric intake. (see page 85 of the Guidelines). Student answers for the calculations will vary - below is a sample calculation:
      • Daily Calorie needs: 200o Cal
      • 10% x 2000 Cal = 200 Cal. No more than 200 Cal should come from added sugars.
      • 1 bottle of Snapple Peach Tea contains 40 g of added sugar according to the label.
      • 40 g sugar x = 160 Cal from added sugar.
      • (160 Cal/200 Cal) x 100 = 80%. Just 1 drink contains 80% of the daily recommended amount of added sugars.
    • Note on calculating the percentage RDA of salt (sodium): this information is provided by most nutrition labels. The Dietary Guidelines suggest an upper limit of 2300 mg per day; the article, “Shaking out the Facts about Salt” nuances that a little. Most labels will assume the limit of 2300 mg.
    • An answer key for sample food items (Snapple Peach Tea and a Chic-Fil-A sandwich) has been provided for teacher reference.
    • The “Evaluate” section of the project can be optional, depending on time available for the project.
  • Ideas for differentiation:
    • Students can use their own estimated daily Calorie needs instead of the standard 2000 Cal. the Dietary Guidelines provide suggestions for this, based on age, sex, exercise level, etc.
    • Task students to use foods/drinks prepared from scratch, without a nutritional label.
    • Provide step-by-step instructions for calculations to students who need more scaffolding.
    • Assist with reading and highlighting necessary information.
    • Providing students only with the necessary pages from the Dietary Guidelines (use the condensed version provided for download).
    • Modify the “Evaluate” section with additional expectations for the (amount, level of details) information provided through the QR-code.

For the Student

Lesson

You have learned about the importance of a balanced diet. You have also learned about the macromolecules that are a part of a healthy diet, carbohydrates, fats (also called lipids) and proteins. But how can you connect all of this to the food you eat every day? What information will help you to make healthy choices? The saying goes “You are what you eat”, but what does that mean exactly? We eat carbohydrates, but we are not a carbohydrate! In the project that you are about to start, you’ll learn more about which elements make up our foods. You will practice identifying relevant information about the foods you eat and you will learn how to analyze this information. Once you have become a master in understanding the nutritional values of the foods you eat, you can communicate what you’ve learned and share it with others. On a Google Site, each class member will share important details about their favorite foods and snacks using a scannable QR code.

Macromolecules Presentation

Your teacher will review carbohydrates, fats and proteins with you.

  1. What is the chemical composition of each?
  2. And what are the nutritional recommendations for each?

Investigation

Determine the recommended daily caloric intake for you. Choose 3 foods, and begin your investigation (it is helpful if your food choices have nutritional labels):

Recommended daily calories for you: Food 1: Food 2: Food 3:
1 Main food group:
2 Recommended % of daily Calories that should come from this food group1 :
3 Calories from this food group in a serving of the food item:
4 % of daily Calories in this food group from this item:
5 Minerals in this food (which and how much):
6 Highest in carbs, fats or protein?:
7 Amount of salt in 1 serving:
8 % of daily recommended salt (sodium) intake
9 Amount of added sugar in 1 serving
10 % of daily recommended sugar intake

1According to Dietary Guidelines for Americans 2020 - 2025, pp. 133 - 136

Source of inspiration for this assignment: Franco-Mariscal, Antonio J., Discovering the Chemical Elements in Food, J.Chem.Educ., 2018, 95, p. 403-409

Guiding questions:

  1. What chemical compounds are found in the foods we consume?
    1. Identify at least 3 chemical compounds in the foods that you picked.
    2. Use the sources below and research to identify what elements make up these compounds. Describe your findings. Focus on at least 1 mineral.
  2. Is the intake of chemical elements through food healthful or harmful?
    1. Identify 3 compounds or elements in your foods with beneficial effects. If there are healthy and unhealthy limits, mention these. Describe the beneficial effects in as much detail as you can.
    2. Identify 3 elements or compounds in your foods with harmful effects. If there are healthy and unhealthy limits, mention these. Describe the harmful effects with as many details as you can find.

Helpful sources of information

Evaluate (Optional)

  1. Create a webpage with your food items in it or on it. Use pictures of your food item if you do not have the box/wrapper/cup anymore.
  2. Replace the image at the top of the page with something relevant to the information that you will put on the page.
  3. Create QR-code for each item with 2-3 sentences of accurate recorded information about one or more of the following:
    1. The food group
    2. A chemical compound in your food item
    3. A mineral or vitamin in your food item
    4. Health benefits of this item
    5. Harmful effects of this item
    6. An example of a good recording for a clementine is: “Clementines are a good source of Vitamin C. Each clementine contains about 1 serving of Vitamin C. Vitamin C is important for a healthy immune system.”
  4. Copy the QR codes and put them on your website, together with the image of each food item.

Rubric

Missing (1) Advancing (2) Meets(3) Exceeds(4)
Explain (30) Address the ‘assignment’ in each row completely and show work for all calculations


Row 1
Row 2
Row 3
Row 4
Row 5
Row 6
Row 7
Row 8
Row 9
Row 10

Extend (21)
  • Question 1a (compound 1-3)
  • Question 1a (compound 4-5)
  • Question 1b
  • Question 2a (compounds / elements description  + limits)
  • Question 2a (description of specific health benefits)
  • Question 2b (compounds / elements description + limits)
  • Question 2b (description of specific harmful effects)
Evaluate (21)
  • 3 QR codes present
  • Each QR code presents a different compound / element
  • Spoken info is clear
  • Spoken info is of appropriate length
  • Display shows organization
  • Three different foods are clearly displayed
  • Display is neat and demonstrates attention and care