Download Organic Compound Lab

Organic Compound Lab
Name: ____________________
Problem: What are the organic compounds found in some common foods?
Pre-lab Questions:
1. What is an indicator? How are indicators used in this experiment?
2. What is the control in this experiment? Why do we need to include it?
3. What does organic mean?
4. What is a monomer? What is a polymer?
Monomer:
5. Draw the “visual vocab” on page 45.
Label the monomer and polymer.
Polymer:
PROCEDURE:
TESTING FOR LIPIDS: Rub the sample onto a brown paper bag. Label it and let it sit for a few minutes. An oily
spot is a positive test for lipids. The paper may become translucent
TESTING FOR STARCH: Put a sample of the solution into a well (around 5-10 drops). Drop 2 drops of iodine on
the sample. A color of blue/ black indicates the presence of starch.
TESTING FOR PROTEIN: Put a sample of the solution into a well (around 5-10 drops). Drop 2 drops of Buirets
on the sample. A color of violet indicates the presence of protein.
TESTING FOR GLUCOSE: Place a sample of your solution in a test tube (10-15 drops). Drop 3-5 drops of
benedicts solution into the test tube. Place the tube into the beaker containing water sitting on the hot plate. Do
not change the heat of the hot plate. Wait for at least 3 minutes. A color of yellow indicates the presence of sugar.
Complete the data table showing the indicators used to test for biomolecules/organic compounds and how
the indicator changes if the biomolecule is present.
Indicator
Biomolecule Tested
Positive result
Lugols
Benedicts
Brown Paper Bag
Biurets
DATA TABLE:
Place an “X” in the column if the solution tested positive for that biochemical/organic compound.
Solution Tested
Water
Carbohydrate
Polysaccharide
Carbohydrate
Lipids
Monosaccharide
Protein
Post Lab Questions:
1. What is the relationship between a polymer and a monomer?
2. People with diabetes are instructed to avoid foods that are rich in carbohydrates. How could your lab
today help you decide whether a food should be served to a person with diabetes?
3. What conclusion could you make if a positive test for any of the organic compounds occurred in the
distilled water?
4. Why can’t Biuret’s reagent be used to test for amino acids? What is Biuret’s testing for?
5. The leaves of many plants are coated with a waxy substance that causes them to shed water. How
would you expect this substance to react in the “sack lunch” test?
6. Use the book and complete the table of the biochemical/organic compounds.
Organic compound
List the functions of each organic
Explain the monomer and polymer of each.
compound. What role do they play?
Protein
Lipid
Carbohydrates
Nucleic Acid