STUDENT GUIDE
ACTIVITY #6: McMush
What’s in a Happy Meal?
The food you eat provides your body with energy and other substances
necessary to carry on life activities. Compounds such as carbohydrates, proteins,
and fats are present in the plants and animals you use as food. Vitamins and
other minerals are obtained from food as well. In this lab, you will learn how to
test for specific compounds and then use those tests to determine if the
compounds are present in a fast food meal.
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What organic and inorganic compounds are present in a McDonald’s
Happy Meal?
How can we test to see if those compounds are there?
GOALS: In this lab activity, you will…
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Identify the reagents used to test for the
presence of certain organic and inorganic
compounds and observe positive test
results.
Identify the organic and inorganic
compounds found in a fast food meal
Determine the nutritional value of a fast
food meal based on lab results.
MAIN IDEAS: The important concepts and skills covered in this activity are…
 The four most important kinds of organic compounds in living things are
carbohydrates, lipids, proteins and nucleic acids. All of these compounds
are found in the food we eat.
 Carbohydrate molecules include simple sugars, double sugars and
starches, which are the preferred energy sources for most organisms.
 Lipids are fats and oils that function in long term energy storage and in the
structure of cell membranes. Proteins may be structural molecules such
as those that form muscles.
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Organic compounds present in foods can be analyzed using reagents
such as Biuret, Sudan III, Benedict’s solution, and iodine.
Inorganic compounds, such as salt and Vitamin C, which are also present
in foods, can be analyzed using reagents such as silver nitrate and
indophenol solution.
ACTIVITY OVERVIEW: A synopsis of this lesson is as follows:
In this activity, students will use qualitative data to analyze the organic and
inorganic compounds present in a fast food meal, including carbohydrates,
protein, fat, vitamins and salt. Initially, students will test known substances for the
presence of these compounds, then perform the same tests on the components
of a McDonald’s Hamburger Happy Meal. The results from that procedure will
allow students to hypothesize about how much nutrition a Happy Meal really
provides based on organic and inorganic compound composition.
CONTEXT: The concepts that we have been developing and how this
activity serves as the ‘next step’ can be explained as follows…
Everything you eat is composed of three macromolecules: carbohydrates,
proteins, and fats. The cells in all living things contain these organic compounds
as well as nucleic acids (another macromolecule) and inorganic compounds such
as vitamins and minerals. This activity will lead well into the Energy in Foods
activity, in which the potential energy in food can be measured. In addition, the
McMush experience will flow into the Observing Mechanical and Chemical
Digestion activity, in which the breakdown of the organic compounds found in
food is explored, and the assimilation of those smaller molecules within the body
is explored as well. At the end of this investigation, students should be able to
use chemical tests to analyze food for organic and inorganic components, and
determine whether a typical fast food lunch contains these organic and inorganic
molecules.
CONNECTIONS
Scientific Content –
 All living things require energy to sustain their life processes. Energy is
obtained by heterotrophs through the food that they eat.
 Organic compounds, in which carbon atoms are combined with hydrogen and
usually oxygen, are important in life processes.
 Organic compounds are usually formed by linking smaller molecules, called
monomers, together in long chains, called polymers.
 The four most important kinds of organic compounds in living things are
carbohydrates, lipids, proteins and nucleic acids. All of these compounds
are found in the food we eat.
 Carbohydrate molecules include simple sugars, double sugars and starches,
which are the preferred energy sources for most organisms. Benedict’s
solution is used to test for the presence of sugar. Iodine is used to test for
the presence of starch.
 Lipids are fats and oils that function in long term energy storage and in the
structure of cell membranes. Sudan III is used to test for the presence of
fats.
 Proteins may be structural molecules such as those that form muscles. Biuret
reagent is used to test for the presence of protein.
 Silver nitrate is used to test for the presence of salt in a sample.
 Indophenol solution is used to test for the presence of Vitamin C in a sample.
Scientific Process –
 There is qualitative data collected in this activity. The students are asked to
use their observational skills to determine whether certain compounds are
present in a sample by observing positive/negative reagent tests.
Math/Graphing –
 There are limited math skills associated with this activity.
Let’s Investigate:
In the activity below, you will learn how to test for the following compounds:
proteins, sugar, starch, vitamin C, salt and fats. Then in Part II, you will apply that
knowledge to testing for the presence of the same compounds in a McDonald’s
Happy Meal.
Part I: Testing of Known Substances
Protein test
1. Place 5 mL of the gelatin solution into one of your test tubes (Test Tube 1).
2. Place 5 mL of distilled water into another test tube (Test Tube 2).
3. Add 1 mL of Biuret solution to each test tube.
4. Observe and record any color change.
Glucose test
1. Place 5 mL of the glucose solution into a clean test tube (Test Tube 1).
2. Place 5 mL of distilled water into another clean test tube (Test
Tube 2).
3. Add 3 ml of Benedict's solution to each test tube. Place the
tube in a beaker of boiling water and boil for five minutes. Use test
tube clamps to take the hot test tubes out of the water bath at the
end of the five minutes.
4. Observe and record any color change.
Starch test
1. Place 5 mL of the starch solution into a clean test tube (Test
Tube 1).
2. Place 5 mL of distilled water into another clean test tube (Test Tube 2).
3. Add 5 drops of Lugol's iodine solution to each test tube.
4. Observe and record any color change.
Vitamin C test
1. Place 5 mLof the vitamin C solution into a clean test tube (Test Tube 1).
2. Place 5 mL of distilled water into another clean test tube (Test Tube 2).
3. Add 5 drops of indophenol solution to each test tube.
4. Observe and record any color change.
Chloride test
1. Place 5 mL of the salt solution into a clean test tube. (Test Tube 1)
2. Place 5 mL of distilled water into another test tube. (Test Tube 2)
3. Add 5 drops of silver nitrate solution to each test tube.
4. Observe and record any color change.
Fats Test
1. Place 10 mL of water in test tube #1.
2. Place 10 mL of oil in test tube #2.
3. Add 10 drops of Sudan III in each of the test tubes. Set the tubes aside for 30
minutes.
4. Carefully examine and describe the results.
Record your results in the data table below:
Table 1: Results of Food Nutrient Tests
Food Substance
Reagent test
Test Tube 1
Results
Test Tube 2
Results
Gelatin
Glucose
Starch
Vitamin C
Sodium chloride
Fat
Part II: McMush
Your teacher will place the Happy Meal in a blender and blend until an emulsion
is prepared. The emulsion will then be filtered, and you will receive some of the
resulting solution.
1. Predict the substances that you expect to find in the McMush solution
in Table 2.
2. Record your predictions in the data table using a “+” or a “-“. Include
the part(s) of the meal that you believe will contain that particular
nutrient.
3. Repeat the reagent tests above using 5 ml of the McMush solution
for each test. Make sure you use clean test tubes for each test.
4. Describe and record your results.
Table 2: McMush Predictions and Results
Food Substance
Protein
Sugar
Starch
Vitamin C
Sodium Chloride
Fat
Prediction and from what part
of the meal
Actual Results
Investigation Reflection:
1. What was the purpose of the distilled water test tube for each of the
nutrient tests from Part 1?
2. List the reagents, and the positive tests for the nutrients in Part 2.
Protein:
Glucose:
Starch:
Vitamin C:
NaCl:
3. Describe the reasons for your predictions in Part 2 in the spaces below.
(For example, “I/we predicted that protein would/would not be in the
McMush because I/we think that _____________________contains
protein”.)
Protein:
Glucose:
Starch:
Vitamin C:
NaCl:
4. How did your predictions compare with your actual results in Part 2?
5. How would you determine which part of the meal contained each
nutrient?
6. If you have access to the Web, go to the following site and follow the online instructions to analyze the Happy Meal:
http://app.mcdonalds.com/countries/usa/food/nutrition/mcmeal/bagmeal.jsp
Make sure you click on “More Details” after you have completed step #4.
(If you do not have Web access, your teacher will supply you with
the nutrition information.)
In Part 2, you only tested for the presence of the nutrients, not the
relative amounts – are your results supported by the nutrition
information supplied by McDonald’s? Explain.
7. How does the presence of fat that you observed compare to the Total Fat
% given on the web site?
8. Compare your Happy Meal % nutrients to the % daily value; you may
assume that an average daily calorie requirement is 2000 calories, and an
average daily protein intake is 40 grams. Do you believe that a Happy
Meal can be part of a balanced diet? Explain your answer.
Investigating Further…
McDonald’s is obviously not the only fast food restaurant out there. Arby’s,
Hardees, Burger King and Wendy’s are also very popular places to pick up a
quick meal. Investigate the presence of sugar, starch, fats (lipids), Vitamin C
and salt in a meal from any one of the other fast food restaurants listed above or
pick another one that wasn’t mentioned. You may
even want to compare the nutritional value of that
meal to the McDonald’s Happy Meal!
Summary of Activity…
You have been asked to write a letter to the CEO of McDonald’s
regarding your findings in this lab. Write a letter that includes the
following:
 The purpose of the lab.
 How to test for each compound present in food, including positive
results.
 What compounds are present in a McDonald’s Happy Meal.
 Whether a McDonald’s Happy Meal can be considered nutritionally
balanced, with data to support your decision.
 Recommendations for changes in the menu based on your findings.
Applying what you have learned…
Migratory birds require a lot of energy to travel along their migratory pathways.
Based on what you have learned in this lab, which organic compound would
provide the necessary energy for these birds? Explain your reasoning.