* Testing for Macromolecules * September 20, 2012 – September 25, 2012 * SBI4U1-01 * Rebekah Alto, Chayene Banta, Taylor Denton, Sarosh, Brianna Madar * Mrs. Kolobaric
Purpose:
To use a set of standardized procedures to test for simple sugars and starch, proteins, and fats.
Hypotheses:
A.)
B.)
C.)
Equipment:
-Safety goggles -Lab apron -400 mL beaker
-Utility stand with ring clamp -Hot plate -Thermometer
-10 mL graduated cylinder -Test-tube racks -8 to 16 test tubes
-Test tube holder -Medicine dropper -Rubber stoppers
-Test-tube brush -Wax pencil -Distilled water
-Depression spot plate -Baking soda solution,5% -Glucose solution, 5%
-Known foods; glucose, corn starch -Cornstarch suspension,5% -Detergent solution
-Unknown food samples -Benedict’s reagent -Lugol’s solution
-Sudan IV indicator -Unglazed brown paper -Gelatine solution, 5%
-Biuret reagent
Procedure: 1. Safety goggles and lab apron were put on.
Part A: Carbohydrate Test
2. Poured 300 mL of water into a 400 mL beaker. Secured the beaker with a ring clamp, placed it on a hot plate, and heated the water to 80 °C.
3. Used a 10 mL graduated cylinder and measured 3 mL of the following: distilled water, baking soda solution, glucose solution, starch solution, bananas, eggs, and oats. Poured each solution into a new, clean test tube.
4. 1 mL of Benedict’s reagent was added to each test tube.
5. Used test tube holder to transfer the test tubes into the hot water bath. Colour changes were recorded after 6 minutes of observations.
6. Placed a drop of distilled water and a drop of Lugol’s solution on a depression spot plate with medicine dropper. Recorded colour of solution.
7. Repeated step 6, but placed a drop of each solution into the spot plate. Recorded the