Name: __________________________________________________________ Date: ______________ Period: ________
Testing for Unknown Organic Compounds
Reagent Demonstration
Reagent
Which Organic Compound Is Being
Tested?
Positive Test Results
Introduction
Several tests have been developed by biologists to determine the presence of the major chemical compounds found in
cells. These tests are called reagent tests. You will use these tests to determine the presence of organic compounds in
an unknown sample.
Materials
Unknown Sample – Letter:
Reaction Tray
Biuret Test Solution, 10 drops
Pipets
Lugol’s Iodine Solution, 1 drop
Glucose Test Strip
Procedures
1. Obtain an unknown organic compound solution from your teacher. Make sure you write down the unknown letter
you received.
2. Place 20 drops of the unknown solution into four different wells on the reaction tray.
3. In the first well, place 10 drops of the biuret test solution. Record the results for the test in the data table.
4. In the second well, place 1 drop of Lugol’s Iodine solution. Record the results for the test in the data table.
5. In the third well, observe if there are any fat droplets floating on the surface of the solution. Record the results for
the test in the data table.
6. Dip a glucose test strip in the fourth well, take it out of the solution, and let it sit for 3 minutes. Using the color key,
record the results for the test in the data table.
7. When you are done, flush the solutions down the sink and clean and dry the reaction tray.
8. Return the unknown solution to your teacher.
Data Table
Reagent
Organic Compound
Being Tested
Test Results
(Description or Color Change)
Positive or Negative
for the Presence of
Organic Compound
1. Which organic compound(s) does your unknown sample contain? _________________________________________
***EXTRA CREDIT STAMP IF YOU GET THE RIGHT ANSWER (MUST HAVE STAMP BEFORE YOU TURN IN LAB)***
2. What is a monomer? _____________________________________________________________________________
3. What is a polymer? _______________________________________________________________________________
4. What is a reagent and what is it used for in biochemistry?
_______________________________________________________________________________________________
_______________________________________________________________________________________________
5. Check the box or boxes that apply to each word below.
Organic Compound
Monosaccharide
Carbohydrate
Fat
Polysaccharide
Steroid
Glucose
Starch
Cellulose
Glycogen
Amino acids
Nucleotide
RNA
Protein
DNA
Nucleic Acids
Polypeptide Chain
Wax
Lipid
Monomer
Polymer
Neither