Dissecting a Cell
Lab
Lab 2a
Title: "Dissecting a Cell" Purpose: The purpose of this lab is to find positive indicator tests for proteins, carbs, and fats. We are also looking for the parts of an egg that test positive as well. Materials: Eggs, Beaker(250 mL), White Vinegar, Plastic Wrap, Slotted Spoon, Sodium Chloride, Distilled Water, Beaker(100 mL), Pipets(5 mL), Pipets Pump(green), Tubes(glass, 13x100 mm), Pegs Racks for 13x100 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, Scalpel Handles(#4), Scalpel blades(#22 for #4 handles), Trays(plastic) Procedure Part I: Step 1: Place uncooked egg in beaker of white vinegar. Cover it in plastic wrap and leave it for 24-48 hours. Wait until the shell dissolves. Step 2: Then, pick up the egg with a slotted spoon and let the vinegar rinse. A chemical reaction should have happened. Step 3: Place the egg in a beaker of 5% NaCl Solution for 24hrs Step 4: Then place the egg in a beaker of distilled water for 24hrs Step 5: Gently slice open the membrane and let the egg white drip through the slotted spoon into a 100mL beaker. Try to get all of the egg white out of the shell w/out piercing the yolk.Step 6: Place egg yolk into a different beaker and set aside the egg membranes. Procedure Part II: Starch Testing: Step 1: Mix 2 mL of a 2% glucose solution + 2 mL of Benedict's solution. Heat for 2 mins in 100 mL of water in a 250-mL beaker at 100 degrees Celsius. Record all of the color changes. Step 2: Mix 2 mL of deionized water and 2 mL of Benedict's solution. Heat for 2 mins in a boiling hot water bath (same as above) and record all of the color changes. Protein Testing: Step 1: 2 mL of gelatin solution and 0.5 mL of 10% NaOH and gently vortex to mix. Add 0.25 mL of 5% copper sulfate and gently mix. Mix well. Record color change after 30 seconds. Step 2: 2 mL of deionized water in a test tube and 0.5 mL of 10% NaOh, and gently vortex to mix. Add 0.25 mL of 5% CuSO4, and gently mix well. Record color change after 30 seconds. Lipid Testing: Step 1: Place 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. Step 2: 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. Procedure Part III: Step 1: Conduct each indicator test (Part II) but substitute each egg component to be tested for sugar, starch, protein, or fat. Step 2: Record results of testing the egg membranes: the yolk (cell cytoplasm) and egg white. Step 3: Give a numerical value to each test result using the following scale: [ 3 = very strong/positive test, 2 = strong/positive test, 1 = weak/positive test, 0 = no color change in indicator/negative ]. Conclusion: In this lab, we looked at the membranes of an egg that we cut open. We learned a lot from this lab including: the proteins of eggs, the right way to open a hard-boiled egg, and much more. I think the two positive things came from this lab were; learning new procedures and starting to get into the flow of a chemistry lab. The other thing would be learning how to properly deal with chemicals instead of just playing around with them. The file below are the results of this lab.
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Date
Started: 8/25/14
Finished: 9/04/14 |