Lab 2a: Dissecting a Cell & Examining its Components
Lab
Lab 2a
Purpose: We are trying to find positive indicators for proteins, carbohydrates, and fats. We want to see whether or not an egg tests positive for proteins, carbohydrates, and fats.
Materials: Eggs, beaker (25 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 tubes, glucose (dextrose), Benedict's Solution, hot plate stirrer, test tube holder, starch (soluble), Lugol's Idoine Solution, Vortex mixer, gelatin, sodium hydroxide, Cupric sulfate 5-hydrate. oil. Sudan IV Solution, scalpel handles #4, scalpel blades #22 (for handles #4), trays (plastic)
Procedure Part I:
1. Put an egg in a beaker of white vinegar. Cover it with plastic wrap and label the beaker. Leave the egg for 24 to 48 hours. Go to Part II while the shell dissolves.
2. After the 24 to 48 hours, pick up the egg with the dissolved egg with the slotted spoon and rinse under water to get rid of vinegar.
3. Feel the outer membranes of the egg. Describe the appearance of the egg after 24 hours.
4. Rinse egg with water. Place egg in beaker of distilled water for another 24 hours. Describe what it looks like after the 24 hours.
5. Slice open the membrane to get the egg cell and let the whites of the egg go through the slotted spoon into the 100 mL beaker. Try and get all the whites out without breaking the yoke.
6. Put the yoke into the beaker and put the egg membrane to the side.
Procedure Part II:
Monosaccharide Indicator Standard Test
1. Test for glucose: In a test tube, mix 2 mL of 2% glucose solution with the Benedict's solution. Heat it in 100 mL of boiling water in the 250 mL beaker for 2 minutes. Record the color changes and the length of time for it to change.
2. Test it for water. Mix 2 mL of deionized water with 2 mL of the Benedict's solution. Heat it for 2 minutes in boiling water. Record time and color change over time.
Starch Indicator Standard Test
1. Mix, by swirling it, 2 mL of mixed starch with 0.25 mL of Lugol's iodine in a test tube. Do not heat it. Record the color change.
2. Test for water. Mix 2 mL of deionized water with the same mix of starch and Lugol's iodine and swirl it. Again, do not heat it. Record color change.
Protein Indicator Standard Test (WEAR GOGGLES AND GLOVES)
1. To test for protein, put 2 mL of gelatin in a test tube. 2. Test for water by adding 2 mL of deionized water in a test tube + 0.5 mL of 10% NaOh + 0.25 mL of 5% CuSO4, and gently mix well. Record color change after 30 seconds.
Lipid Indicator Standard Test
1. Test for lipids by placing a drop of oil (100% fat) on a piece of brown paper bag. Let it dry for 10 minutes. Hole paper to light, record how much passes through the spot.
2. Test for water by place drop of water on a piece of brown paper bag. Let it dry for 10 minutes. Hold paper to light, record amount of passing light.
Lab 2a
Purpose: We are trying to find positive indicators for proteins, carbohydrates, and fats. We want to see whether or not an egg tests positive for proteins, carbohydrates, and fats.
Materials: Eggs, beaker (25 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 tubes, glucose (dextrose), Benedict's Solution, hot plate stirrer, test tube holder, starch (soluble), Lugol's Idoine Solution, Vortex mixer, gelatin, sodium hydroxide, Cupric sulfate 5-hydrate. oil. Sudan IV Solution, scalpel handles #4, scalpel blades #22 (for handles #4), trays (plastic)
Procedure Part I:
1. Put an egg in a beaker of white vinegar. Cover it with plastic wrap and label the beaker. Leave the egg for 24 to 48 hours. Go to Part II while the shell dissolves.
2. After the 24 to 48 hours, pick up the egg with the dissolved egg with the slotted spoon and rinse under water to get rid of vinegar.
3. Feel the outer membranes of the egg. Describe the appearance of the egg after 24 hours.
4. Rinse egg with water. Place egg in beaker of distilled water for another 24 hours. Describe what it looks like after the 24 hours.
5. Slice open the membrane to get the egg cell and let the whites of the egg go through the slotted spoon into the 100 mL beaker. Try and get all the whites out without breaking the yoke.
6. Put the yoke into the beaker and put the egg membrane to the side.
Procedure Part II:
Monosaccharide Indicator Standard Test
1. Test for glucose: In a test tube, mix 2 mL of 2% glucose solution with the Benedict's solution. Heat it in 100 mL of boiling water in the 250 mL beaker for 2 minutes. Record the color changes and the length of time for it to change.
2. Test it for water. Mix 2 mL of deionized water with 2 mL of the Benedict's solution. Heat it for 2 minutes in boiling water. Record time and color change over time.
Starch Indicator Standard Test
1. Mix, by swirling it, 2 mL of mixed starch with 0.25 mL of Lugol's iodine in a test tube. Do not heat it. Record the color change.
2. Test for water. Mix 2 mL of deionized water with the same mix of starch and Lugol's iodine and swirl it. Again, do not heat it. Record color change.
Protein Indicator Standard Test (WEAR GOGGLES AND GLOVES)
1. To test for protein, put 2 mL of gelatin in a test tube. 2. Test for water by adding 2 mL of deionized water in a test tube + 0.5 mL of 10% NaOh + 0.25 mL of 5% CuSO4, and gently mix well. Record color change after 30 seconds.
Lipid Indicator Standard Test
1. Test for lipids by placing a drop of oil (100% fat) on a piece of brown paper bag. Let it dry for 10 minutes. Hole paper to light, record how much passes through the spot.
2. Test for water by place drop of water on a piece of brown paper bag. Let it dry for 10 minutes. Hold paper to light, record amount of passing light.
stem_table_1.docx | |
File Size: | 13 kb |
File Type: | docx |
Procedure Part III:
1. Do each indicator test in Part II but substitute each egg part so it can be tested for sugar, starch, protein, or fat.
2. Record your results of testing the egg membranes including the yolk and egg white.
3. Give a numerical value to each test result using this f scale: (3 = very strong/positive test, 2 = strong/positive test, 1 = weak/positive test, 0 = no color change in indicator/negative)
1. Do each indicator test in Part II but substitute each egg part so it can be tested for sugar, starch, protein, or fat.
2. Record your results of testing the egg membranes including the yolk and egg white.
3. Give a numerical value to each test result using this f scale: (3 = very strong/positive test, 2 = strong/positive test, 1 = weak/positive test, 0 = no color change in indicator/negative)
stem_table_2.docx | |
File Size: | 13 kb |
File Type: | docx |
Data Analysis/Conclusion:
We tested certain solutions for glucose, carbohydrates, proteins, and fats. We did this and recorded color change. After recording these color changes, we tested the egg whites, yokes, and membrane for these things and comparing the color change from the previous tests. The whites tested for everything. The yokes tested positive for lipids and either weak or not at all for the other components. The membrane tested positive for proteins and fats and a little glucose.
Reflection:
I thought that this lab was very interesting and cool to see. I eat eggs all the time and I did not know that eggs had all these things in them. I thought it was fun to test the different components of the egg to see what it tested positively and negatively for. The lab, as our first lab, was a great way to teach us how to use the different resources and materials. My group and I worked very well and did this lab very efficiently as well as correct to get the right results.
We tested certain solutions for glucose, carbohydrates, proteins, and fats. We did this and recorded color change. After recording these color changes, we tested the egg whites, yokes, and membrane for these things and comparing the color change from the previous tests. The whites tested for everything. The yokes tested positive for lipids and either weak or not at all for the other components. The membrane tested positive for proteins and fats and a little glucose.
Reflection:
I thought that this lab was very interesting and cool to see. I eat eggs all the time and I did not know that eggs had all these things in them. I thought it was fun to test the different components of the egg to see what it tested positively and negatively for. The lab, as our first lab, was a great way to teach us how to use the different resources and materials. My group and I worked very well and did this lab very efficiently as well as correct to get the right results.