Purpose: To use indicator solutions to test and identify proteins, carbohydrates, and fats in an egg.
Materials:
Materials:
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Procedure
Procedure: Part I
- Put a raw egg in a beaker of white vinegar, label, cover with plastic wrap, and leave for 24-28 hours. (Meanwhile proceed to Part II)
- After 24-48 hours when the shell has dissolved, pick up the egg with the slotted spoon and rinse with water.
- Observe outer layers of the cell. Place egg in a beaker of 5% NaCl solution for 24 hours and describe the difference.
- Rinse egg again, and place in a beaker of distilled water for 24 hours. Describe appearance of the egg.
- Slice open the egg's membranes and allow the egg white to drip through the slots of the slotted spoon into the 100 mL beaker.
- Place the yolk into a new beaker and set aside the membranes.
Procedure: Part II
Monosaccharide Indicator Standard Test
Starch Indicator Standard Test
Monosaccharide Indicator Standard Test
- Test for glucose: Mix 2 mL of a 2% glucose solution with 2 mL of Benedict's Solution in a test tube, then heat for two minutes in boiling hot water. Record color changes and the length of time that the colors took to appear.
Starch Indicator Standard Test
- Test for starch: mix 2 mL of starch suspension with 0.25 mL of Lugol's iodine, and gently swirl to mix, do not add heat. Record changes.
- Test for water: mix 2 mL of deionized water with 0.25 mL of Lugol's iodine, and gently swirl to mix, do not add hear. Record changes.
- Test for protein: Place 2 mL of gelatin solution in a test tube. Wearing safety gear, add 1 mL of biuret solution and gently mix. Record color change.
- Test for water: Place 2 mL of deionized water in a test tube, Wearing safety gear, add 1 mL of biuret solution and gently mix. Record color change.
- Test for lipids: add 60 ul of Sudan IV solution to 2 mL of the sample, gently mix. Red is the negative lipid test and orange is positive.
Procedure: Part III
- Conduct every indicator test but substitute the egg component to test instead of the sugar, starch, or protein. Do not add the standard solutions.
- Record results on another data table.
- Give a value to each result (3 = very strong, 2 = strong, 1 = weak, 0 = none/negative). Include a brief description of color changes.
Data and Results
Part I:
1: Calcium Carbonate + Vinegar --> Water + Carbon Dioxide. We placed the egg in a beaker of vinegar and the shell dissolved. This left the egg cell surrounded with a thin and permeable outer membrane.
2: Egg + Salt Water. We placed the egg in a beaker of salt water. As the concentration of salt in the water was greater than that within the egg, it passed through the membrane and into the egg. The egg shrank noticeably.
3: Egg + Water. We placed the egg in a beaker of deionized water. The water entered the egg cell and it grew considerably. Since the amount of water in it was greater than before the contents were under pressure, which explains why the egg burst when we cut it open
Part II:
1: Calcium Carbonate + Vinegar --> Water + Carbon Dioxide. We placed the egg in a beaker of vinegar and the shell dissolved. This left the egg cell surrounded with a thin and permeable outer membrane.
2: Egg + Salt Water. We placed the egg in a beaker of salt water. As the concentration of salt in the water was greater than that within the egg, it passed through the membrane and into the egg. The egg shrank noticeably.
3: Egg + Water. We placed the egg in a beaker of deionized water. The water entered the egg cell and it grew considerably. Since the amount of water in it was greater than before the contents were under pressure, which explains why the egg burst when we cut it open
Part II:
colorchangetimetrials.docx | |
File Size: | 5 kb |
File Type: | docx |
This chart explains the color changes of all of our items and when they occurred.
Part III:
untitleddocument.docx | |
File Size: | 5 kb |
File Type: | docx |
This chart explains color changes and assigns a numerical value depending on the strength at which the material tested.
Data Analysis and Conclusion:
We went through the experiments with starch solutions, glucose solutions, and protein solutions prior to using the egg components as well as doing negative control experiments so we would know what positive and negative tests might look like. When we tested it, the egg yolk tested positive for glucose, protein, and lipids, and negative for starch. The whites tested positive for protein and glucose, as did the membranes. Any error in our results could be due to simple human error: misreading results, measuring incorrectly, neglecting to regulate the temperature of substances used in or on the tubes, etc. We could fix all of this by more closely watching our actions, repeating experiments multiple times, and working in more controlled environments.
Indicator tests can be used for lots of things; they can test the level of glucose in a diabetic person's urine, they can be used for drug testing, environmental testing, regulating levels of certain substances in any environment (environment, water supplies, etc). Indicator tests can be used in any instance to indicate the presence or lack thereof a substance.
We went through the experiments with starch solutions, glucose solutions, and protein solutions prior to using the egg components as well as doing negative control experiments so we would know what positive and negative tests might look like. When we tested it, the egg yolk tested positive for glucose, protein, and lipids, and negative for starch. The whites tested positive for protein and glucose, as did the membranes. Any error in our results could be due to simple human error: misreading results, measuring incorrectly, neglecting to regulate the temperature of substances used in or on the tubes, etc. We could fix all of this by more closely watching our actions, repeating experiments multiple times, and working in more controlled environments.
Indicator tests can be used for lots of things; they can test the level of glucose in a diabetic person's urine, they can be used for drug testing, environmental testing, regulating levels of certain substances in any environment (environment, water supplies, etc). Indicator tests can be used in any instance to indicate the presence or lack thereof a substance.
Reflection:
I liked that we got to do everything by ourselves, unlike stuff in middle school, where teachers would administer chemicals and do half of the projects for us. We got to use all the equipment, heat elements, cutting, etc., on our own and I think we all learned a lot more from that. It was a good lab to get us acquainted with all the new lab equipment. I found some of the reactions really interesting and they were fun to carry out. Both Cate and I worked together well, and we never ran into any collaboration issues. The only thing I might have changed is our organization, and this carries out into the other class as well. There were dozens of dirty pipettes in our bins, but none of them were labeled so we couldn't use them. We could have saved a lot of waste if they were labeled from the start. The bottoms of the bins were also covered in oil and what other mystery substances, and it was gross and unsanitary. If we all would take time to label our equipment and clean up our spills we wouldn't make such a mess and wouldn't waste so many materials.
I liked that we got to do everything by ourselves, unlike stuff in middle school, where teachers would administer chemicals and do half of the projects for us. We got to use all the equipment, heat elements, cutting, etc., on our own and I think we all learned a lot more from that. It was a good lab to get us acquainted with all the new lab equipment. I found some of the reactions really interesting and they were fun to carry out. Both Cate and I worked together well, and we never ran into any collaboration issues. The only thing I might have changed is our organization, and this carries out into the other class as well. There were dozens of dirty pipettes in our bins, but none of them were labeled so we couldn't use them. We could have saved a lot of waste if they were labeled from the start. The bottoms of the bins were also covered in oil and what other mystery substances, and it was gross and unsanitary. If we all would take time to label our equipment and clean up our spills we wouldn't make such a mess and wouldn't waste so many materials.