Organic Compound # 2

Experiment # 9 Testing for Protein

Materials Needed:
* Protein chemical indicator (see below for details)
* Flour
* cheesecloth
* bouillon
* Dextrostik strips  or Cinitest (to test sugar)
* Iodine (to test carbohydrates)
* a variety of food

Chemical Indicator : a mixture of household ammonia with a few drops of 3% copper sulfate solution

Procedure:
1) Add some chemical indicator mixture to milk. What color do you observed?

L-carbo test; R-protein (#4,5)

2) Dissolve a bouillon cube in hot water and test with protein chemical indicator. What did you observe?
3) Obtain a cup of flour and mix with water to form a stiff paste. Knead for about 10 minutes, put into a cheesecloth and continue kneading under water. Continue rinsing until the water becomes milky.
4) Test the water for carbohydrates. What were your results?
5) Test the water for protein. What were your results?
6) Test a portion of the residue in the cheesecloth for carbohydrate. What were your results?
7) Test the residue for protein. What were your results?
8) Discuss results in steps 4, 5, 6 and 7.
9) Try various foods to see if they contain protein.
10) Write a summary of your results of this experiment.

Top: R- meat tested for protein; Below: L-residue tested, R- fruits tested

Findings:
* Soluble starch from flour paste dissolves in water
* Insoluble residue left in the cheesecloth is protein
* Meat has protein
* Fruits tested do not have protein