Lab 2a: Cell Disection
Date: August 25, 2014
Purpose- What are positive indicator tests for proteins, carbohydrates, and fats? Do parts of an egg test positive for protein, carbohydrates, and/ or fats?
Materials
Eggs - Glass Tubes, 13 X 100 mm Sodium hydroxide
250 mL beaker - Peg racks for 13 X 100 mm tubes Cupric sulfate 5-hydrate
White Vinegar - Glucose (dextrose) Oil
Plastic Wrap - Benedict's Solution Sudan IV Solution
Slotted spoon - Hot plate stirrer Scalpel handles #4
Sodium chloride - Test tube holder Scalpel blades #22 for #4 handles
Distilled Water - Soluble starch Plastic trays
100 mL beaker - Lugol's Iodine Solution
5 mL pipets - Vortex mixer
Green pipet pump - Gelatin
Procedure part 1
1. Place uncooked egg into beaker with white vinegar. Label and cover with plastic wrap. leave for 1-2 days
2. Gently pick up the egg with spoon and rinse it off with water to remove vinegar
3. Feel outer membrane. To verify that water can enter and leave the cell easily, place egg in 5% NaCl solution for 1 day.
4. Rinse egg. Place egg in beaker of distilled water for 1 day.
5. To get egg cell, gently slice open the egg's membrane and let egg white drip through slots of spoon into 100 mL beaker. Don't pierce the yolk.
6. Place egg yolk into another beaker, and set aside membranes.
Procedure part 2
Monosaccharide Indicator Test
1. Test for glucose: In a test tube, mix 2 mL of a 2% glucose, solution with 2 mL of Benedict's solution. Heat for 2 min. in a boiling water bath. Record your observations.
2. Test for water (negative control): In a test tube, mix 2 mL of deionized water with 2 mL Benedict's solution. Heat for 2 min. in a boiling hot water bath. Record your observations.
Starch Indicator Test
1. Test for starch: In a test tube, mix 2 mL of well-mixed starch suspension with 0.25 mL of Lugol's iodine. Swirl the mix. Record observations.
2. Test for water: in a test tube, mix 2 mL of deionized water with 0.25 mL of Lugol's iodine. Swirl the mix. Record observations
Protein Indicator Test (wear gloves and goggles!!!)
1. Test for protein: Put 2 mL of gelatin solution in test tube. Add 0.5 mL of 10% NaOH and gently vortex it. Add 0.25 mL of 5% of copper sulfate and mix gently. Record observations.
2. Test for water: Pour 2 mL of deionized water in a test tube. Add 0.5 mL of 10% NaOH and gently vortex it. Add 0.25 mL of 5% of copper sulfate and mix gently. Record observations.
Lipid Indicator Test
1. Test for lipid(s): Add Sudan IV to the oil and mix well.
2. Test for water: Add Sudan IV to
Procedure part 3
1. Conduct each indicator test but substitute each egg part to be tested.
2. Record the results of the egg membranes, yolk, and the egg white for all 4 molecules.
3. Use a number to the strength or weakness of the color variation.
Purpose- What are positive indicator tests for proteins, carbohydrates, and fats? Do parts of an egg test positive for protein, carbohydrates, and/ or fats?
Materials
Eggs - Glass Tubes, 13 X 100 mm Sodium hydroxide
250 mL beaker - Peg racks for 13 X 100 mm tubes Cupric sulfate 5-hydrate
White Vinegar - Glucose (dextrose) Oil
Plastic Wrap - Benedict's Solution Sudan IV Solution
Slotted spoon - Hot plate stirrer Scalpel handles #4
Sodium chloride - Test tube holder Scalpel blades #22 for #4 handles
Distilled Water - Soluble starch Plastic trays
100 mL beaker - Lugol's Iodine Solution
5 mL pipets - Vortex mixer
Green pipet pump - Gelatin
Procedure part 1
1. Place uncooked egg into beaker with white vinegar. Label and cover with plastic wrap. leave for 1-2 days
2. Gently pick up the egg with spoon and rinse it off with water to remove vinegar
3. Feel outer membrane. To verify that water can enter and leave the cell easily, place egg in 5% NaCl solution for 1 day.
4. Rinse egg. Place egg in beaker of distilled water for 1 day.
5. To get egg cell, gently slice open the egg's membrane and let egg white drip through slots of spoon into 100 mL beaker. Don't pierce the yolk.
6. Place egg yolk into another beaker, and set aside membranes.
Procedure part 2
Monosaccharide Indicator Test
1. Test for glucose: In a test tube, mix 2 mL of a 2% glucose, solution with 2 mL of Benedict's solution. Heat for 2 min. in a boiling water bath. Record your observations.
2. Test for water (negative control): In a test tube, mix 2 mL of deionized water with 2 mL Benedict's solution. Heat for 2 min. in a boiling hot water bath. Record your observations.
Starch Indicator Test
1. Test for starch: In a test tube, mix 2 mL of well-mixed starch suspension with 0.25 mL of Lugol's iodine. Swirl the mix. Record observations.
2. Test for water: in a test tube, mix 2 mL of deionized water with 0.25 mL of Lugol's iodine. Swirl the mix. Record observations
Protein Indicator Test (wear gloves and goggles!!!)
1. Test for protein: Put 2 mL of gelatin solution in test tube. Add 0.5 mL of 10% NaOH and gently vortex it. Add 0.25 mL of 5% of copper sulfate and mix gently. Record observations.
2. Test for water: Pour 2 mL of deionized water in a test tube. Add 0.5 mL of 10% NaOH and gently vortex it. Add 0.25 mL of 5% of copper sulfate and mix gently. Record observations.
Lipid Indicator Test
1. Test for lipid(s): Add Sudan IV to the oil and mix well.
2. Test for water: Add Sudan IV to
Procedure part 3
1. Conduct each indicator test but substitute each egg part to be tested.
2. Record the results of the egg membranes, yolk, and the egg white for all 4 molecules.
3. Use a number to the strength or weakness of the color variation.
Results
Part I: Qualitative data
After the egg was in the vinegar solution and produced water (H2O), Carbon dioxide (CO2) and H2CO3. Water also got into the membrane.
1. CaCO3 + CH3COOH -> H2O + CO2 + H2CO3 This is what happened when we put the egg into the vinegar.
2. When we put the egg into the saltwater, the egg got smaller because the salt got into the egg while the water stayed outside of the egg.
3. When we put the egg into the regular water, the egg grew back into regular size because the salt got drawn out and the water got inthside the egg.
Part II and III: Data Tables
Part I: Qualitative data
After the egg was in the vinegar solution and produced water (H2O), Carbon dioxide (CO2) and H2CO3. Water also got into the membrane.
1. CaCO3 + CH3COOH -> H2O + CO2 + H2CO3 This is what happened when we put the egg into the vinegar.
2. When we put the egg into the saltwater, the egg got smaller because the salt got into the egg while the water stayed outside of the egg.
3. When we put the egg into the regular water, the egg grew back into regular size because the salt got drawn out and the water got inthside the egg.
Part II and III: Data Tables
Data Analysis
We began by doing the positive and negative tests for 4 indicators (protein, glucose, starch, and lipids) and then using that data to test the egg components for those chemicals. You could see the positive and negative results from the above table. The only standard that the egg membrane reacts to is glucose. The egg white and yolk react to all 4 tests so they have all of the indicators
There could have been a couple of errors in this lab, especially human error. We could have mixed things improperly. We could have added the wrong indicators. Or we could have measured incorrectly. All of those errors could have lead to a false negative or positive in the tests.This is a real test that scientists use to find out if some substances has certain things in it.
Reflection
This was an OK experiment for a couple of reasons. One reason is that feeling the egg without the shell was pretty disgusting. Another reason is that when we tried to make a small hole in the egg membrane, the yolk and the egg white fell into the same cup so we had to separate it by hand. But I liked testing the different solutions, that part was fun. Overall, it was a decent lab.
We began by doing the positive and negative tests for 4 indicators (protein, glucose, starch, and lipids) and then using that data to test the egg components for those chemicals. You could see the positive and negative results from the above table. The only standard that the egg membrane reacts to is glucose. The egg white and yolk react to all 4 tests so they have all of the indicators
There could have been a couple of errors in this lab, especially human error. We could have mixed things improperly. We could have added the wrong indicators. Or we could have measured incorrectly. All of those errors could have lead to a false negative or positive in the tests.This is a real test that scientists use to find out if some substances has certain things in it.
Reflection
This was an OK experiment for a couple of reasons. One reason is that feeling the egg without the shell was pretty disgusting. Another reason is that when we tried to make a small hole in the egg membrane, the yolk and the egg white fell into the same cup so we had to separate it by hand. But I liked testing the different solutions, that part was fun. Overall, it was a decent lab.