Lab 2a dissecting an egg
purpose:
To find possible indicator tests for proteins, carbohydrates, and fats. To see what parts of the egg test positive for proteins, carbohydrates, and fats.
Materials:
Eggs 250 ml beaker white vinegar plastic wrap slotted spoon sodium distilled water 100 ml beaker 5 ml pipets green pipet pump 13x100 mm glass tube 13x100 peg rack tubes glucose 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 scalpel handles scalpel blades plastic trays
Procedure:
Part 1:
1. place an uncooked egg into a beaker of white vinegar cover it with plastic wrap and leave it for on to two days.
2. after the elapsed time the shell will dissolve in the vinegar. take the egg out with a spoon and and rinse in water.a chemical reaction will occur
3. feel the outer membrane of the cell. the outer membrane gives a good model of the cell membrane. Place the egg in a 5% NaCL solution for one day. describe the apperence of the egg after.
4. gently rinse the egg and place it in distilled water for one day. After describe the aperence of the egg
5. Gently slice open the egg membranes and let the egg white drip out into a 100 ml beaker.
6. place the egg yolk into another beaker and set aside the egg membrane.
Part 2:
1. mix 2 ml of 2% glucose solution with 2 ml of benedict's solution. heat for 2 minutes in hot water then record all color changes.
2. Mix 2 ml of deionized water with 2 ml of Benedict's solution in a test tube. Heat it in the same beaker and heat as before. Once again make note of color changes that happen.
3. Mix 2 ml of mixed start suspension with .25 ml of Lugol's iodine. record all color changes
4. mix 2 ml of deionzined water with .25 ml of Lugol's iodine. Softly mix these together. Once again do not heat the solution! Make note of the color change.
5. Put 2 ml of gelatin in a test tube and add 0.5 mL of 10% NaOH and mix, Add 0.25 mL of 5% copper sulfate and mix. while doing so wear goggles and gloves. Note the color changes.
6. put 2 ml of deionized water in a test tube and add 0.5 of 10% NaOH and mix, Add 0.25 mL of 5% copper sulfate and mix. Wait 30 seconds and note the color change you observe.
7. Write down the amount of light that passes though the oil spot, in a percentage.
8. Place a drop of water on a brown paper bag, then let it dry for ten minutes. Put it up to a light and then write down what percentage of light passes through.
Part 3:
1. Substitute each egg to be tested for starch, sugar, protein, or fat. As you may have noticed part 2 is the same, but this time we have changed what is being tested.
2. Be sure to write down the results from the egg membranes, the egg white, and the yolk.
3. Make a numerical value for test results that you have gotten by using the system in the key. Also note any color changes that occur.
Part I:
1. The hard outside of the shell dissolved into the vinegar, only the membrane of the egg remaned.
2. In the experiment, the salt water replaced the tap water which made it look smaller.
3. When the egg was placed back in water, the saltwater solution inside the egg returns to outside the egg. The regular water enters the egg, causing it to be bigger. This explains why the egg contents bursted out when we cu
Part 2 and 3 Data Tables:
Data Analysis
The positive indicator tests for carbohydrates, fats, and proteins are done by comparing the results from our fixed, or controlled, tests with our uncontrolled ones. By observing the change in color for each experiment we can draw a conclusion based on the fixed tests. Once my group did controlled tests for glucose, carbohydrates, proteins, and fats for positive or negative controls, we wrote the data of that experiment, and conducted the same experiments on the egg whites, yolk, and membrane and recorded the color changes from that. By comparing the results from that experiment to the controlled data, my group was able to know what the result was.
The greatest sources of error was us. Human error happen a lot in this lab. Partly because it was are first time doing anything like this and partly because we were too lazy to label things especially when using the pipets. Although it is possible that we did not mix up the pipets, I am fairly certain we did. I the future I will make sure to label everything because if you do not it can ruin your entire experiment or worse.
Reflection:
In this project learned a lot of new things about eggs and conducting a biology experiment. My favorite part was being able to see the inside of the egg. I also liked seeing the three different parts of the egg split up. My partner, Nick Bergo, and I worked well together. Knowing him for a while I new that we would be an efficient team and that we would still have an enjoyable time. I believe that we Stayed on topic, for the most part, used our time wisely, and did not struggle with sharing of ideas or responsibility. If I were to do this lab again I would take more time to label things and focus on detail.
The positive indicator tests for carbohydrates, fats, and proteins are done by comparing the results from our fixed, or controlled, tests with our uncontrolled ones. By observing the change in color for each experiment we can draw a conclusion based on the fixed tests. Once my group did controlled tests for glucose, carbohydrates, proteins, and fats for positive or negative controls, we wrote the data of that experiment, and conducted the same experiments on the egg whites, yolk, and membrane and recorded the color changes from that. By comparing the results from that experiment to the controlled data, my group was able to know what the result was.
The greatest sources of error was us. Human error happen a lot in this lab. Partly because it was are first time doing anything like this and partly because we were too lazy to label things especially when using the pipets. Although it is possible that we did not mix up the pipets, I am fairly certain we did. I the future I will make sure to label everything because if you do not it can ruin your entire experiment or worse.
Reflection:
In this project learned a lot of new things about eggs and conducting a biology experiment. My favorite part was being able to see the inside of the egg. I also liked seeing the three different parts of the egg split up. My partner, Nick Bergo, and I worked well together. Knowing him for a while I new that we would be an efficient team and that we would still have an enjoyable time. I believe that we Stayed on topic, for the most part, used our time wisely, and did not struggle with sharing of ideas or responsibility. If I were to do this lab again I would take more time to label things and focus on detail.