Lab 2a; Dissecting a Cell and Examining its Components
Purpose: Finding positive indicator tests for proteins, carbohydrates, and fats, and finding the parts of eggs that test positive for proteins, carbohydrates, and/ or fats.
Materials: Eggs, Beaker, 250 mL, White vinegar, Plastic wrap, Slotted spoon, Sodium chloride, Distilled water, Beaker, 100 mL, Pipets, 5 mL, Pipet pump,green, Tubes,glass,13 x 100 mm, Peg racks for 13 x 100 mm tubes, Glucose (dextrose), Benedict's solution, Hot plate stirrer, Test tube holder, Starch,soluble, Lugol's Iodine Solution, Vortex mixer, Gelatin, Sodium hydroxide, Cupric sulfate 5-hydrate, Oil, Sudan IV Solution, Scapel handles, #4, Scapel blades, #22 for #4 handles, Trays,plastic
Procedure:
Part I
1. Put uncooked egg into a beaker of white vinegar. Label and cover with plastic wrap. Leave it for 24- 48 hours. While the shell dissolves, proceed to Part II.
2. The shell should have dissolved in the vinegar after 24 hours. Gently pick up egg with the slotted spoon and rinse it in water to remove the vinegar and find out what chemical reactions occur.
3. Feel the outer membranes of the cell and should that make a good model of a cell membrane. They are thin, flexible, and are permeable to some substances. Place the egg in a beaker of 5% NaCl solution for 24 hours in order to verify that water can enter and leave the cell. Also to look at appearance of egg after 24 hours.
4. Gently rinse off egg with water and place the egg in the beaker of distilled water for 24 hours. Once again describe what the egg looks like after the 24 hours has past.
5. Retrieve the egg by slicing open the egg's membrane, and let the egg white go through the slots in the spoon into the 100-mL beaker. Try getting the egg white into the beaker without harming the yolk.
6. Place the yolk into a different beaker.
Part II Testing Standard Solutions
Monosaccharide Indicator Standard Test
1. Mix 2 mL of 2 % glucose with 2 mL of Benedict's solution. Heat for 2 minutes in boiling water. Record all color changes and ellapsed time for each color to appear.
2. Test for water: mix 2 mL of deionized water with 2 mL of Benedict's Solution. Heat 2 minutes in hot water and record color changes.
Starch Indicator Standard Test
1. Mix 2 mL of starch with 0.25 mL of Lugol's iodine. Mix, don't heat, and record changes.
2. Test water: Mix 2 mL of deionized water with 0.25 mL of Lugol's iodine. Mix, don't heat, and record changes.
Protein Indicator Standard Test
1. Place 2 mL of gelatin in test tube. After putting on protective gear add 0.5 mL of 10% NaOH and mix. Add 0.25 mL of 5% copper sulfate and mix. Record color changes after 30 seconds.
2. Place 2 mL of deionized water in same test tube as 0.5 mL of 10% NaOH and 0.25 mL of 5% copper sulfate. Mix all and record after half a minute.
Lipid Indicator Standard Test
1. Place drop of oil on a piece of paper bag. Let it settle for 10 minutes and then hold the paper to light. Record how much light passes through.
2. Place drop of water on brown bag and let it settle for 10 minutes. Then record how much light passes through the area.
Part III Molecular Composition of Egg Components
1. Do each indicator test but change each egg component to be tested for the sugar, starch, protein, and fats. All variables from Part II should be the same, only the unknowns should be changed. Do not add any standard solution.
2. Record all results for egg membrane, yolk, and egg whites for all four molecules.
3. Give a number value to each test and record into the data table and remember to have a short description of color change.
Data/Results
Part I. Qualitative observations
1. Egg + Salt Water: The salt water passed through the egg, but regular water left the egg and because of this the egg looked smaller.
2. Egg + Water: When the egg was placed back into regular water the salt water exited the egg and the regular water enters leaving the egg to look bigger.
3. Calcium Carbonate + Vinegar -- Water + Carbon Dioxide: The shell of the egg dissolved into the egg, just leaving the membranes.
Part II. Date Tables-Color Changes/Time
Part III. Data Table- Color change and numerical value
Purpose: Finding positive indicator tests for proteins, carbohydrates, and fats, and finding the parts of eggs that test positive for proteins, carbohydrates, and/ or fats.
Materials: Eggs, Beaker, 250 mL, White vinegar, Plastic wrap, Slotted spoon, Sodium chloride, Distilled water, Beaker, 100 mL, Pipets, 5 mL, Pipet pump,green, Tubes,glass,13 x 100 mm, Peg racks for 13 x 100 mm tubes, Glucose (dextrose), Benedict's solution, Hot plate stirrer, Test tube holder, Starch,soluble, Lugol's Iodine Solution, Vortex mixer, Gelatin, Sodium hydroxide, Cupric sulfate 5-hydrate, Oil, Sudan IV Solution, Scapel handles, #4, Scapel blades, #22 for #4 handles, Trays,plastic
Procedure:
Part I
1. Put uncooked egg into a beaker of white vinegar. Label and cover with plastic wrap. Leave it for 24- 48 hours. While the shell dissolves, proceed to Part II.
2. The shell should have dissolved in the vinegar after 24 hours. Gently pick up egg with the slotted spoon and rinse it in water to remove the vinegar and find out what chemical reactions occur.
3. Feel the outer membranes of the cell and should that make a good model of a cell membrane. They are thin, flexible, and are permeable to some substances. Place the egg in a beaker of 5% NaCl solution for 24 hours in order to verify that water can enter and leave the cell. Also to look at appearance of egg after 24 hours.
4. Gently rinse off egg with water and place the egg in the beaker of distilled water for 24 hours. Once again describe what the egg looks like after the 24 hours has past.
5. Retrieve the egg by slicing open the egg's membrane, and let the egg white go through the slots in the spoon into the 100-mL beaker. Try getting the egg white into the beaker without harming the yolk.
6. Place the yolk into a different beaker.
Part II Testing Standard Solutions
Monosaccharide Indicator Standard Test
1. Mix 2 mL of 2 % glucose with 2 mL of Benedict's solution. Heat for 2 minutes in boiling water. Record all color changes and ellapsed time for each color to appear.
2. Test for water: mix 2 mL of deionized water with 2 mL of Benedict's Solution. Heat 2 minutes in hot water and record color changes.
Starch Indicator Standard Test
1. Mix 2 mL of starch with 0.25 mL of Lugol's iodine. Mix, don't heat, and record changes.
2. Test water: Mix 2 mL of deionized water with 0.25 mL of Lugol's iodine. Mix, don't heat, and record changes.
Protein Indicator Standard Test
1. Place 2 mL of gelatin in test tube. After putting on protective gear add 0.5 mL of 10% NaOH and mix. Add 0.25 mL of 5% copper sulfate and mix. Record color changes after 30 seconds.
2. Place 2 mL of deionized water in same test tube as 0.5 mL of 10% NaOH and 0.25 mL of 5% copper sulfate. Mix all and record after half a minute.
Lipid Indicator Standard Test
1. Place drop of oil on a piece of paper bag. Let it settle for 10 minutes and then hold the paper to light. Record how much light passes through.
2. Place drop of water on brown bag and let it settle for 10 minutes. Then record how much light passes through the area.
Part III Molecular Composition of Egg Components
1. Do each indicator test but change each egg component to be tested for the sugar, starch, protein, and fats. All variables from Part II should be the same, only the unknowns should be changed. Do not add any standard solution.
2. Record all results for egg membrane, yolk, and egg whites for all four molecules.
3. Give a number value to each test and record into the data table and remember to have a short description of color change.
Data/Results
Part I. Qualitative observations
1. Egg + Salt Water: The salt water passed through the egg, but regular water left the egg and because of this the egg looked smaller.
2. Egg + Water: When the egg was placed back into regular water the salt water exited the egg and the regular water enters leaving the egg to look bigger.
3. Calcium Carbonate + Vinegar -- Water + Carbon Dioxide: The shell of the egg dissolved into the egg, just leaving the membranes.
Part II. Date Tables-Color Changes/Time
Part III. Data Table- Color change and numerical value
lab_2a.gdoc | |
File Size: | 0 kb |
File Type: | gdoc |
Conclusion
First we composed positive and negative indicator tests for carbohydrates, proteins, lipids, and starch(glucose) and took data from it. If the color changes we then can know that the solution is positive. We did all these experiments on the eggs also and recorded color changes and the duration of each change. Using this we could see if the tests were positive or negative.
1. The membrane tested very well especially for lipids and proteins.
2. The egg whites tested positive for everything but for starch and lipids it tested horribly.
3. The egg yolk tested bad for every component. It tested positive for lipids.
Many errors could have lead to false results. For example for each measurement of each solution might not have been exact creating slightly different answers. Also we didn't measure the temperature of the boiling of the water so we would never have known how hot it was which will vary the results. In the real world people use indicator test to detect the presence of specific organic or inorganic compounds such as fats, sugars, and salts. Indicator tests are also known to find the ph scales of a solution.
Reflection
There were many things to like about this experiment. I like to mix things together to see what would happen and in this case I can but it is more controlled. Also i found it interesting that the egg shell completely dissolved in the vinegar. I think me and in this case Matt performed somewhat well. I got a little side tracked at times but I think we worked very efficiently. Next time I would try to keep the egg more on the tray than on my shirt but besides that this experiment definitely proved to help learn something new and a great way to start the year.
First we composed positive and negative indicator tests for carbohydrates, proteins, lipids, and starch(glucose) and took data from it. If the color changes we then can know that the solution is positive. We did all these experiments on the eggs also and recorded color changes and the duration of each change. Using this we could see if the tests were positive or negative.
1. The membrane tested very well especially for lipids and proteins.
2. The egg whites tested positive for everything but for starch and lipids it tested horribly.
3. The egg yolk tested bad for every component. It tested positive for lipids.
Many errors could have lead to false results. For example for each measurement of each solution might not have been exact creating slightly different answers. Also we didn't measure the temperature of the boiling of the water so we would never have known how hot it was which will vary the results. In the real world people use indicator test to detect the presence of specific organic or inorganic compounds such as fats, sugars, and salts. Indicator tests are also known to find the ph scales of a solution.
Reflection
There were many things to like about this experiment. I like to mix things together to see what would happen and in this case I can but it is more controlled. Also i found it interesting that the egg shell completely dissolved in the vinegar. I think me and in this case Matt performed somewhat well. I got a little side tracked at times but I think we worked very efficiently. Next time I would try to keep the egg more on the tray than on my shirt but besides that this experiment definitely proved to help learn something new and a great way to start the year.