Name : ________________________
Date: _____________
Period: _____
Living Environment
Lab
Organic Mystery Food Lab
#2
Organic molecules are any molecule that contains hydrogen and carbon
atoms. As long as there is at least one of each (carbon & hydrogen) the molecule is
organic.
Inorganic molecules are any molecule that does not have both hydrogen and carbon
in it. Inorganic molecules may contain carbon like, CO2; and it may contain
hydrogen like H2O, but it cannot have them together.
An organic molecule can fall into one of four groups: Carbohydrates (sugar
& starch), Lipids (fats), Proteins and Nucleic Acids. You may have seen these words on the back of boxes of
food and on bottles of juice. These words are found on nutrition labels. These nutrition labels tell you how
much of an organic molecule is in your food. This is important because some food contains more of one group
than other.
The Experiment
A terrible mix up has happened at Northside General Hospital. The nurses forgot to label the patients’
supplemental foods. This is terrible; each food has been designed with patients’ organic molecule needs in
mind. The nurses had prepared 1 supplement rich in glucose, 1 supplement rich in starch, 1 supplement rich in
Protein and 1 supplement rich in Fats. One for each of the patient’s needs.
Patient 1 is deficient in lipids, Patient 2 is deficient in sugars, he has low energy and needs a huge
amount of sugars, patient 3 is also deficient in sugars and has low energy however, this patient has a condition
in which he cannot break down starches and other polysaccharides, Patient 4 is deficient in proteins. The nurses
had prepared 4 supplemental foods, one for each patient: one high in lipids, one high in starch, one high in
glucose and one high in proteins.
First figure out what supplement each patient needs
Patient
What are they
Does the patient have any
number
deficient in?
special conditions that
affect their diet?
1
2
3
4
What supplemental
food do they need?
(Which organic
molecule)
What is the
function of the
macromolecule
they need?
Lucky for the patients, the Doctor is familiar with indicators. An Indicator is a chemical used to detect the
presence of a particular molecule. The Doctor knows that a specific indicator called Benedics Solution can be
used to test for Glucose. Benedict’s solution is a clear, light blue liquid that turns orangey-brown in the presence
of glucose. The Dr also knows that Iodine a.k.a Lugol’s solution can be used to test for starch. Iodine is a
clear, amber color liquid that turns dark blue or in the presence of starch. Biuret’s’s solution can be used to test
for protein. Biuret’s solution is a blue solution that turns bright prink or violet in the presence of protein and a
Brown Paper bag can be used to test for lipids and a brown paper bags turn dark when in contact with lipids.
The Dr comes up with the following procedure to figure out which supplement contains the organic molecules
and therefore which supplement belongs to the patients. You will follow this procedure to find out the mystery
supplements. You will follow the procedure.
On your desk you have:


10 test tubes labeled
A, B, C, D and E.
5 Droppers



Iodine
Benedics solution
Buriet’s Solution

And 5 pieces of a
brown paper bag
Note: Never let the Tip of the droppers touch any substance other that what you are dropping.
Ms Reid will demonstrate.
Ms Reid also recommends that you check off each step as you do it so you won’t do something
twice.
Procedure:
1. Take one of the test tubes labeled A and drop 10 drops of benedicts into the test tube
2. Repeat step 1 with 1 test tube labeled B, 1 labeled C, 1 Labeled D and 1 labeled E
3. Place all these test tubes with Benedicts solution into the Hot water bath as instructed by
your teacher. We have to wait for this reaction.
4. Take 1 drop from the Test Tube A left on your table and place it on 1 piece brown of brown
paper bag. Rub the sample against the paper bag. Note if sample looks turns dark stays light
and write findings in chart B
5. Repeat step 1 with next 4 samples (B,C, D and E) while comparing them to Sample A which
is waters being used for our control.
6. Take the test tube labeled A and place 1 dropper full of the sample in each the 2 wells
labeled A on your table.
7. Repeat step 6 with each of the next 4 test tubes labeled B, C D and E
8. Next add 5 drops of iodine into each of the first 5 wells marked A,B,C,D and E. You should
have only 1 well of each letter sample with Iodine.
9. Note the changes in the samples in chart B.
10. Next add 5 drops of Buiret’s Solution into each of the last 5 wells marked A,B,C,D and E.
You should have only 1 well of each letter sample with Buiret
11. Ask Ms Reid to collect your Benedicts test from the hot water bath.
12. Note the changes in the samples in chart B.
13. Clean the lab area.
a. Take trays to the sink, throw samples down the drain rinse the trays
b. Empty the benedicts test tubes down the drain and ask Ms Reid to refill tubes with
new samples from large beakers
14. Answer the post lab questions
Chart B
Test
tube
Letter
A
Lipids test
Dark+ or
Light-
Iodine
Blue black + or
Stays Amber -
Buiret’s
Bright pink+
or stays blue
Benedicts test
Orange Red + or
stays Clear blue
What does
his sample
contain?
Water
Sample belongs
to patient 1,2, 3
or 4
Control group
B
C
D
E
Post Lab Questions
1. What are indicators?
2. What does Iodine test for?
3. What does Benedicts Solution test for?
4. What does Buiret’s solution test for?
5. What do we use the Brown paper bag to test for?
6. What did you have to do different to the Benedics test that we did not have to do for the other tests?
7. What are some reasons we used water in test tube A?
8. Why do think these “indicators” react differently for starches and sugars, even though they are both
carbohydrates?
9. Explain what could happen to patients 2 and 3 if they did not receive the carbohydrates they need?