PURPOSE
What are positive indicator test for proteins, carbohydrates, and fats? Do parts of an egg test positive for protein, carbohydrate, and or fat?
MATERIALS
Eggs
Beaker, 250 mL
White vinegar
Plastic wrap
slotted spoon
Sodium Chloride
Distilled water
Beaker, 500 mL
Pipets, 5 mL
Pipet Pump, green
Tubes, glass, 13x100 mm
Peg racks for 13x100 mm tubes
Glucose (dextrose)
Benedicts Solution
Hot plate stirrer
Test tube holder
Starch, soluble
Lugol's Iodine solution
Vortex mixer
Gelatin
Sodium Hydroxide
Cupric Sulfaate 5-hydrate
Oil
Sudan IV solution
Scalpel handles, #4
Scalpel blades, #22, for #4 handles
Trays, plastic
Beaker, 250 mL
White vinegar
Plastic wrap
slotted spoon
Sodium Chloride
Distilled water
Beaker, 500 mL
Pipets, 5 mL
Pipet Pump, green
Tubes, glass, 13x100 mm
Peg racks for 13x100 mm tubes
Glucose (dextrose)
Benedicts Solution
Hot plate stirrer
Test tube holder
Starch, soluble
Lugol's Iodine solution
Vortex mixer
Gelatin
Sodium Hydroxide
Cupric Sulfaate 5-hydrate
Oil
Sudan IV solution
Scalpel handles, #4
Scalpel blades, #22, for #4 handles
Trays, plastic
PURPOSE
Procedure Part I: Separating Cell Structures
1. Put an uncooked egg in a beaker of vinegar and wrap the beaker with plastic wrap. Leave it for 24 to 48 hours. Meanwhile do part II.
2. When egg dissolves, gently pick up the egg with a slotted spoon and rinse it in water to remove the vinegar. What chemicals were the reactants and products?
3. Feel the outer membrane of the cell. The outer membrane (different from the membrane around the yolk) is good model of a cell membrane. They are thin, flexible, and permeable to some substances. To prove that water can enter and exit the membrane. place the egg in a beaker of 5% NaCl solution for 24 hours. What may have caused the change in appearance.
4. Rinse the egg of with water. Once again, place the egg in a beaker of distilled water for 24 hours. Describe the eggs appearance after 24 hours. What changed the appearance.
5. Gently slice open the eggs membrane, and let the egg white drip through the slots of the spoon into a 100 mL beaker in order to get the egg cell. Try to get all of the egg white into the beaker without piercing the yolk (egg cell with clear, flimsy cell membrane around it.)
6. Put the yolk into another beaker, and set aside the egg membranes.
2. When egg dissolves, gently pick up the egg with a slotted spoon and rinse it in water to remove the vinegar. What chemicals were the reactants and products?
3. Feel the outer membrane of the cell. The outer membrane (different from the membrane around the yolk) is good model of a cell membrane. They are thin, flexible, and permeable to some substances. To prove that water can enter and exit the membrane. place the egg in a beaker of 5% NaCl solution for 24 hours. What may have caused the change in appearance.
4. Rinse the egg of with water. Once again, place the egg in a beaker of distilled water for 24 hours. Describe the eggs appearance after 24 hours. What changed the appearance.
5. Gently slice open the eggs membrane, and let the egg white drip through the slots of the spoon into a 100 mL beaker in order to get the egg cell. Try to get all of the egg white into the beaker without piercing the yolk (egg cell with clear, flimsy cell membrane around it.)
6. Put the yolk into another beaker, and set aside the egg membranes.
Procedure Part II: Testing Standard Solutions
Monosaccharide Indicator Standard Test
1. Test for Glucose: Mix 2 mL of a 2% glucose ( a monosaccharide) solution with 2 mL of Benedict's solution in a test tube. Heat 100 mL of water in a 250 mL beaker to 100 degrees C. Place the test tube in this water for 2 minutes. Record all the color changes the amount of time it takes for each change.
2. Test for water (negative control): 2 ml of deionized water with 2 mL of Benedict's Solution in a test tube. Heat 100 mL of water in a 250 mL beaker to 100 degrees C. Place the test tube in this water for 2 minutes. Record all the color changes the amount of time it takes for each change.
Starch Indicator Standard Test
1. Test for starch: Mix 2 mL of starch suspension(that has been mixed) with 0.25 mL of Lugol's iodine. Swirl to mix these. Don't heat. Record the color changes.
2. Test for water (negative control): Mix 2 mL of ionized water with 0.25 mL of Lugol's iodine. Swirl to mix these. Don't heat. Record the color changes.
Protein Indicator Test
Caution: Sodium Hydroxide (NaOH) is a strong, base and it is caustic; can burn. Follow lab safety procedures.
1. Test for protein: Place 2 mL of gelatin (protein) solution in a test tube. Add 0.5 mL of 10% NaOH and gently vortex to mix. Now add 0.25 mL of 5% copper sulfate (CuSO4) and mix. This NaOH and CuSO4 mixture is called Biuret reagent. Record the color change after 30 secs.
2. Place 2 mL of deionized water in a test tube. and 0.5 mL of 10% NaOH and gently vortex to mix. Now add 0.25 mL of 5% copper sulfate (CuSO4) and mix. Record the color change after 30 secs.
Sudan IV Indicator Test
1. Add 0.6 mL of Sudan to 2 mL of fat and then 2mL of water.
1. Test for Glucose: Mix 2 mL of a 2% glucose ( a monosaccharide) solution with 2 mL of Benedict's solution in a test tube. Heat 100 mL of water in a 250 mL beaker to 100 degrees C. Place the test tube in this water for 2 minutes. Record all the color changes the amount of time it takes for each change.
2. Test for water (negative control): 2 ml of deionized water with 2 mL of Benedict's Solution in a test tube. Heat 100 mL of water in a 250 mL beaker to 100 degrees C. Place the test tube in this water for 2 minutes. Record all the color changes the amount of time it takes for each change.
Starch Indicator Standard Test
1. Test for starch: Mix 2 mL of starch suspension(that has been mixed) with 0.25 mL of Lugol's iodine. Swirl to mix these. Don't heat. Record the color changes.
2. Test for water (negative control): Mix 2 mL of ionized water with 0.25 mL of Lugol's iodine. Swirl to mix these. Don't heat. Record the color changes.
Protein Indicator Test
Caution: Sodium Hydroxide (NaOH) is a strong, base and it is caustic; can burn. Follow lab safety procedures.
1. Test for protein: Place 2 mL of gelatin (protein) solution in a test tube. Add 0.5 mL of 10% NaOH and gently vortex to mix. Now add 0.25 mL of 5% copper sulfate (CuSO4) and mix. This NaOH and CuSO4 mixture is called Biuret reagent. Record the color change after 30 secs.
2. Place 2 mL of deionized water in a test tube. and 0.5 mL of 10% NaOH and gently vortex to mix. Now add 0.25 mL of 5% copper sulfate (CuSO4) and mix. Record the color change after 30 secs.
Sudan IV Indicator Test
1. Add 0.6 mL of Sudan to 2 mL of fat and then 2mL of water.
Procedure Part III: Molecular Composition of Egg Components
We will need to test each egg component for monosaccharides, starch, protein, and lipid.
1. Conduct each indicator test as in Part II except substitute each egg component
2. Record to results of testing the egg components for all four molecules on the table below.
3. Give a numerical value to each test result using the following scale: [ 3=very strong/ positive test; 2 = strong/positive; 1 =weak/positive; 0 = no color change in indicator/negative] Also describe the color changes.
1. Conduct each indicator test as in Part II except substitute each egg component
2. Record to results of testing the egg components for all four molecules on the table below.
3. Give a numerical value to each test result using the following scale: [ 3=very strong/ positive test; 2 = strong/positive; 1 =weak/positive; 0 = no color change in indicator/negative] Also describe the color changes.
DATA
Data Part I
Data Part I Diagram | |
File Size: | 0 kb |
File Type: | gdraw |
Data Part II
Part II Talbe | |
File Size: | 0 kb |
File Type: | gdoc |
Data Part III
Part III Table | |
File Size: | 0 kb |
File Type: | gdoc |
DATA ANALYSIS
In this lab we learned that certain substances can act as identifiers for certain substances and how certain solutions can act with an egg. We were able to dissolve an eggs shell with vinegar and this shows that vinegar can dissolve calcium. We were also able to identify the effect salt water can have when placed in a beaker with a shell-less egg. I analyzed this effect in the Data Part I. In Part II we identified substances with indicators. The lab was set up so that the substances we tested were positive for the indicator to test that substance. This helped us to see what color meant a positive result for which indicators. Basically, we were able to identify positive results because positive indicator tests for proteins, fats, and carbohydrates are done through comparing solutions with and without the control. We were also able to conclude that water had a negative test result for every indicator. In Part III we applied the knowledge and tested the membrane, yolk, and egg white for each each indicator. Based on the color, we could tell how positive the egg part was for a substance. For example, the membrane was a 3 (very Positive) for Biuret, this helped us find out there was protein here. In the end we concluded the following about the egg parts:
1. The egg whites tested positive for all components. It tested weakly for glucose and fat, but very strongly for protein and starch.
2. The egg yolk tested weakly for most of the components, like glucose and starch. The yolk tested negative for protein, but strongly positive for lipids.
3. The egg membrane tested positive for all components. It tested weakly for glucose, but strongly for protein and fat. Though not as obvious, there was still a significant indication of starch in the membrane.
Another use of the indicators could be to change the color of a liquid for visual aesthetics, similar to a water dyes. These indicators should mostly just be used for indicating these substances. You could use indicators to reveal unsafe substances, such as an indicator that reveals radiation. Ph sticks are a good example of indicators.
As with almost every experiment, errors arose in our lab work. Human failure was the main error in this lab. When using the pipet tubes, we forgot to label the first couple because we were unaware we had to do so. This resulted in a bunch of tubes that were unlabeled and we ended up cross contaminating a little bit. This resulted in bad data results so we had to re do a couple, which put us on pressure for time to finish all the other test. Even though this affected our lab, we learned from this mistake that it is important to label your tools, be organized, and never to cross contaminate substances. Temperature in the water bath was another possible error. We did not measure the temperature and this could have affected our color change. We could have used a thermometer to fix this error. Another error we had was we didn't fully read one of the procedures were it told us to heat up the test tube. We instead just assumed that we should mix it like all the others. We later corrected our result, but we learned that assumptions are not a part of lab work and that it can result in hazards. Also, we realized that something as simple as heating a substance up can change the entire result. One of the positives about this lab was we learned how to use pipets to measure liquid volumes. Another thing I learned was that things we might not expect to be very reactive, such as an egg, can actually be reactive with the right substances. I found this very interesting.
This was a fairly simple lab, but if I could improve upon it I would like to have more explanation of what exactly happens on the molecular level between the egg parts and the indicators. There were not any other improvements to this lab but if I would add on some more experimenting. I would like to experiment with more substances to observe more about how the indicators work and what type of substances they effect. I would have also liked to experiment with how heat can effect color change in a substance.
1. The egg whites tested positive for all components. It tested weakly for glucose and fat, but very strongly for protein and starch.
2. The egg yolk tested weakly for most of the components, like glucose and starch. The yolk tested negative for protein, but strongly positive for lipids.
3. The egg membrane tested positive for all components. It tested weakly for glucose, but strongly for protein and fat. Though not as obvious, there was still a significant indication of starch in the membrane.
Another use of the indicators could be to change the color of a liquid for visual aesthetics, similar to a water dyes. These indicators should mostly just be used for indicating these substances. You could use indicators to reveal unsafe substances, such as an indicator that reveals radiation. Ph sticks are a good example of indicators.
As with almost every experiment, errors arose in our lab work. Human failure was the main error in this lab. When using the pipet tubes, we forgot to label the first couple because we were unaware we had to do so. This resulted in a bunch of tubes that were unlabeled and we ended up cross contaminating a little bit. This resulted in bad data results so we had to re do a couple, which put us on pressure for time to finish all the other test. Even though this affected our lab, we learned from this mistake that it is important to label your tools, be organized, and never to cross contaminate substances. Temperature in the water bath was another possible error. We did not measure the temperature and this could have affected our color change. We could have used a thermometer to fix this error. Another error we had was we didn't fully read one of the procedures were it told us to heat up the test tube. We instead just assumed that we should mix it like all the others. We later corrected our result, but we learned that assumptions are not a part of lab work and that it can result in hazards. Also, we realized that something as simple as heating a substance up can change the entire result. One of the positives about this lab was we learned how to use pipets to measure liquid volumes. Another thing I learned was that things we might not expect to be very reactive, such as an egg, can actually be reactive with the right substances. I found this very interesting.
This was a fairly simple lab, but if I could improve upon it I would like to have more explanation of what exactly happens on the molecular level between the egg parts and the indicators. There were not any other improvements to this lab but if I would add on some more experimenting. I would like to experiment with more substances to observe more about how the indicators work and what type of substances they effect. I would have also liked to experiment with how heat can effect color change in a substance.
REFLECTION
I found this lab to be very informational and interesting. I found it interesting how we can use indicators to tell what a substance may contain. The way that one substance, the indicator, can help identify another substance because that other substance changed the indicator's color is very cool. This makes identifying substances a lot easier. I also like the tools we got to use and learn about. Lastly, I though the color changes and changes of the eggs appearance were very cool and marvelous to look at.
My partners, Kyle Rockwell and Brandon Kelly, were very helpful and we all collaborated very smoothly. We each contributed equally to the lab work and helped each other with the procedure questions. We discussed possibilities and answers together during and after the lab. This was useful because we were able to confirm our questions with each other. I feel that I had good leadership in this lab, I was the one who organized the procedures and when we were going to do them. This was critical to our labs success. Brandon and Kyle both took leadership when it came to caring out the procedures.
My partners, Kyle Rockwell and Brandon Kelly, were very helpful and we all collaborated very smoothly. We each contributed equally to the lab work and helped each other with the procedure questions. We discussed possibilities and answers together during and after the lab. This was useful because we were able to confirm our questions with each other. I feel that I had good leadership in this lab, I was the one who organized the procedures and when we were going to do them. This was critical to our labs success. Brandon and Kyle both took leadership when it came to caring out the procedures.