NAME: ________________________________DATE:___________ BLOCK: _______
Due to your excellent background in organic chemistry, you have been hired by Dr.
Oliver Border of the Lancaster County Medical Examiners Office to clear up a situation.
During some confusion with previous laboratory technicians, samples of stomach
contents from 5 murder victims got mixed up! Since these specimens will serve as
evidence in pending murder trials it is essential that this mistake be corrected. The only
information that you have about these murder victims is what their last meal was.
Hopefully your knowledge of organic chemistry will enable you to fill in the gaps and you
will be able to match different stomach contents samples with their “owners”. You
should follow the procedures (found on pages 3 – 5) for identifying various organic
molecules including monosaccharides, starch, lipids, and proteins. Information about
the last meals of the 5 victims is as follows:
NAME OF VICTIM
LAST MEAL
Wendell Sputz
A bag of jelly beans
and a baked potato
Margaret Little
A bag of Skittles and
iced tea
U. R. Downs
Plain spaghetti
Lucy Wunderchomper
Davis O’Leary
A Big Mac Value Meal
supersized with an
extra order of
supersized fries and a
shake
A very lean steak and
a glass of water
1
PREDICT TYPE(S) OF
MACROMOLECULE(S)
FOUND IN LAST
MEAL
Set up the experiment to test the five stomach contents samples using all 4 tests. The
stomach contents have already been labeled 1-5. Record your results in Table 3-1 and
analyze your results to determine which stomach contents belong to which murder
victims. Put your conclusions in Table 3-2. GOOD LUCK!
MATERIALS
Safety goggles
Five test tubes
Test tube rack
Test tube holder
Benedict's solution
Iodine solution
Biuret's solution
Brown bag paper
Marker
Hot plate with hot water bath
Test tube brush
Soapy water for clean up
Stomach contents of 5 victims
DIRECTIONS FOR LIPIDS (FATS) TESTING
Observation
MANDATORY: MAKE SURE YOUR GOGGLES ARE ON!
1. Look at each of the stomach contents. Decide which ones look greasy and mark your
results in Table 3-1.
2
DIRECTIONS FOR CARBOHYDRATES TESTING
Part 1- Monosaccharide (Sugar) Testing (Benedict’s)
1. Place 20 drops of each stomach contents in the appropriately labeled test tube.
2. Place 10 drops of the Benedict's solution in each test tube.
3. Mix gently by swirling the test tube.
CAUTION: Benedicts is poisonous! If you get Benedict’s solution on your skin then
wash it off immediately with soapy water. Clean up any spills on lab top with soapy
water.
4. Place the test tubes in the hot water bath and heat for up to 5 minutes.
5. Remove the test tubes with a test tube holder after changes have occurred and place in
the test tube rack until results are recorded.
CAREFUL: Tubes are hot!
6. ANALYSIS: Benedict's solution turns from clear blue to a cloudy orange/red or even
green or yellow in the presence of a monosaccharide.
7. Record results in the data table.
8. Clean the test tubes using a test tube brush and soapy water. Rinse well.
Part 2- Starch Testing (Iodine)
1. Add 1 dropper full of each stomach contents into 5 correctly labeled test tubes.
2. Place 3 drops of iodine solution into each test tube.
3. ANALYSIS: The iodine solution will change from brown to a dark purple/black color in
the presence of starch.
4. Record the results in the data table.
5. Clean the test tubes using a test tube brush and soapy water. Rinse well.
3
DIRECTIONS FOR PROTEIN TESTING
Biuret Test
1. Place 20 drops of each stomach contents in each of the appropriately labeled test
tubes.
2. Add 1 dropper full of biuret solution into each test tube.
3. ANALYSIS: Look for a color change. A positive result for protein will be a purple color
(do not confuse purple with blue).
4. Record results in the data table.
5. Clean the test tubes with the brush and soapy water. Rinse well.
RESULTS
TABLE 3-1
TEST
ORGANIC
MOLECULE
Observation
Lipids
(fats)
Benedict’s
Monosaccharide
(sugar)
Iodine
Starch
Biuret
Protein
Stomach Stomach Stomach Stomach Stomach
Contents Contents Contents Contents Contents
1
2
3
4
5
(Use + for present and – for not present)
(Or use “yes” for present and “no” for not present)
4
TABLE 3-2
Match the victim with the correct stomach contents number.
NAME OF VICTIM
Wendell Sputz
Margaret Little
U. R. Downs
Lucy Wunderchomper
Davis O’Leary
LAST MEAL
NUMBER OF
STOMACH
CONTENTS
A bag of jelly
beans and a
baked potato
A bag of Skittles
and tea with
honey
Plain spaghetti
A Big Mac Value
Meal supersized
with an extra
order of
supersized fries
and a shake
A very lean steak
and a glass of
water
CONCLUSION
Instructions:
Type a letter to Dr. Oliver Border analyzing your data and stating your conclusions (see
example attached). For example:
U.R. Downs tested positive for only starch because he ate plain spaghetti, which is high in
starch. Therefore, U.R. Downs stomach contents are #2.
Your letter must be typed! You should have a logo for your company on your letter. Include
an introduction and conclusion in your letter in addition to your explanation of your
results. Remember, you are a chemist who could be called to testify about what you find. Be
truthful! If you are not sure of your results then say so! Also include if and where any errors
in procedure may have caused the information that you collected to be even slightly unreliable.
Finally, your letter must include 2 data tables similar to Tables 3-1 and 3-2 in the lab. Design
your tables in Microsoft Word of Excel (whichever you prefer).
5
CV Corpse Co
Ahead of the Rest
1234 Autopsy Lane
Honolulu, HI 55525
Dr. Oliver Border
Lancaster County Coroners Office
555 N. Duke Street
Lancaster, PA 17601
August 14, 1969
Dear Dr. Border:
Include the following in 1-3 paragraphs:
 An introduction that includes why you were hired.
 The results of the tests and explanation of the results. Because Margaret Little ate
skittles and drank tea, her stomach contents contain only sugar, which matches
stomach contents #2.
 List the errors that may have occurred, how they might have affected your results, and
what you would do to minimize those results in the future.
 Two data tables
 Brief conclusion that thanks Dr. Border for his business.
Sincerely,
Tara S. Flick, PhD.
6