Accelerated Biology
Macromolecules Notebook Lab
Case Study:
You are a new hire at Needham’s elite crime lab. A “John Doe” was found in the Town Forest. The police
are not sure who he is or how he died, but they want to use the clues left on the body to investigate what his
last days may have been like. They will then use his last steps to try to find witnesses who may know who
he is and how he died.
The detective who searched his body found 3 restaurant receipts. Unfortunately, the portion where he
signed his credit card and the time/date appear were ripped off. Luckily though, the name of the restaurants
and the meals he purchased were on the page. Here is what he ate:
Bertucci’s Needham:
Spaghetti with pomodoro sauce
Dinner rolls (assume with olive oil)
Nutritional information: http://www.bertuccis.com/mobile/nutrition/nutritioncategory.php
Orange Leaf Needham:
Mango Frozen Yogurt
Fresh pineapple topping
Gummy bears
Nutritional information: http://orangeleafyogurt.com/nutrition
Five Guys, Dedham:
Cheeseburger
Lettuce, Tomato, Mayo
French Fries
Nutritional information: http://www.fiveguys.com/menu/nutritional-information.aspx
The state medical examiner’s office have sent over the contents of his stomach. It looks like a gooey,
grayish mash, but contains the nutrition from his last dinner. Hopefully, your analysis of this material will
help to understand his final days and provide valuable clues to his death.
Pre-Lab Homework:
Go to each of the nutrition websites and determine what types of macromolecules are in each meal. You
should indicate the total grams of food the meal provides, how many grams each of: simple sugars
(monosaccharides & dissacharides), starch (digestible polysaccharides), fiber (non-digestible
polysaccharides), protein & lipids (fat). Write this on the first page in your lab notebook!
Introduction:
Describe what an indicator does. You may use pH as an example. The indicators available to you are as
follows.
Indicator
Molecule it tests for
Benedict’s Solution
Biuret’s Solution
Iodine Solution
Sudan III
Hypothesis:
Using the nutrition facts, make a hypothesis for each meal. (If…then…because…)
Methods:
Choose one of the indicators and describe how the indicator was used to test for the substance.
Follow the directions at each lab station to test your sample, the positive control substance (provided at the
station), and the negative control substance (provided at the station).
Be sure to test your sample with all four tests! Even if you don’t think it will have a certain
macromolecule, you need to confirm this using your tests!
Data and Analysis:
Graph:
Calculate the total grams/serving for each meal. Then calculate the % of the diet made up of (simple
sugars, polysaccharides (separate fiber and starch), proteins, lipids)
For each of the meals, make a pie chart showing the total % of each type of molecule.
Controls Table:
Indicator
Positive Control
Substance
Positive Control
Result
Negative Control
Substance
Negative Control
Result
Benedict’s
Biuret’s
Iodine
Sudan III
Sample Table: (Use the results from your control to analyze the results)
Sample Test
Color Change
Analysis
Make a written trend to identify the key results of the experiment. What was the last meal that the John Doe
ate based on the information from the nutrition facts compared with the analysis of the stomach contents.
Conclusions:
Accept or reject each of the hypotheses using your data. Draw a conclusion based on the available data
about where the victim ate his last meal and explain the reason for your conclusion.
Discuss in general sources of each of the macromolecules that the indicator test for. Research and explain
what a balanced meal should have for: sugars, starch, fiber, fats, protein. Were any of the meals our victim
ate balanced? Suggest a well-balanced meal.
Error:
a) Why is it important to run positive and negative controls when using indicators?
b) Describe the terms “false positive” and “false negative”. See if you can identify any examples in your
data. (If not, explain what an example of each would be and why these might show up in a test.
c) Is this test qualitative or quantitative? What are the limitations of this test? How might this be a source
of error?