Name___________________________________________ Hour________ Date___________________

Murder and a Meal

The Case

A murder has occurred right here in our peaceful little town of East Peoria, IL. As top-notch biology students at East Peoria High School you have been asked to assist in the investigation of this most unfortunate incident. Central to identifying the individual who committed this crime is establishing where the victim was the day of the crime so that detectives can question the individuals with whom the victim came into contact. An autopsy was performed on the victim has revealed that the victim ate just prior to the time of death. Upon questioning the victim’s friends and family, detectives working the case have learned that the victim enjoyed eating at the following places.

Tie Dye Pizza  

The victim would never eat thin crust pizza from anywhere else! The victim would typically order a pizza with sausage, pepperoni, and bacon.

What macromolecules would you find here?

Maxwell’s Sports Bar:

The victim would hang out here to watch sporting events while feasting on Blazin’ wings and celery.

What macromolecules would you find here?

Olive Garden: 

The victim loved to go here for a night of bread, olive oil, and pasta.

What macromolecules would you find here?

The forensic pathologist has removed the contents of the victim’s stomach for you to analyze in order to determine where the victim had his last meal.

Lesson developed by Camron J. Stanley 2008

Procedure Before analyzing the stomach contents of the deceased, you must study the tests and get a teacher signature clarifying that you understand the directions.

Food Tests

Sugar Test: ­Benedict's solution

Benedict's solution is used to test for simple sugars, such as glucose. It is a clear blue solution of sodium and copper salts. In the presence of simple sugars, the blue solution changes color to green, yellow, and brick-­red, depending on the amount of sugar.

What to do.

1. Mix small amount of each food sample with distilled water test liquid.

2. To a test tube, add 40 drops of liquid to be tested.

3. If testing more than one liquid, label each test tube with a marker.

4. Add 10 drops of Benedict's solution to each test tube. Carefully heat the test tubes by suspending in a hot water bath for 5 minutes.  

 5. Note any color change. If sugar is present solution will turn green, yellow,    or brick-­red, depending on sugar concentration.

 Protein ­ Test: Biuret Solution

Biuret solution is used to identify the presence of protein. Biuret reagent is a blue solution that, when it reacts with protein, will change color to pink­-purple.

What to do.

1. To a test tube, add 40 drops of liquid to be tested.

2. If testing more than one liquid, label each test tube with a marker.

3. Add 3 drops of Biuret reagent solution to each test tube. Shake gently..

4. Note any color change. Proteins will turn solution pink or purple.

Lipid Test

Watch Video:

Starch Test: Iodine Solution


Data Table






Chemical Test

Positive Test Result

Negative Test Result



Not Present


Study the data table. Based on the results, indicate which macromolecules are:

  1. Most present (For example, was the starch test just sort of gray or was it dark black)
  1. Lipid______________________________________
  2. Protein____________________________________
  3. Sugar_____________________________________
  4. Starch____________________________________
  1. Not Present at all (put a check on the line of those not present.):
  1. Lipid______        b. Protein_______       c. Sugar_______     d. Starch________


Detective Boneparte had her last meal at _____________________________ because _____________ ____________________________________________________________________________________ _____________________________________________________________________.

Lesson developed by Camron J. Stanley 2008