Lab 2a - "Dissecting" a "Cell" and Examining Its components
Purpose-
What are the positive indicator tests for proteins, carbohydrates, and fats?
Do parts of an egg test positive for proteins, carbohydrates, and/or fats?
What are the positive indicator tests for proteins, carbohydrates, and fats?
Do parts of an egg 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, 13x100mmm Peg 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 Handels, #4 Scalpel blades, #22, for #4 handles Trays, plastic
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, 13x100mmm Peg 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 Handels, #4 Scalpel blades, #22, for #4 handles Trays, plastic
Procedure #1-
1. Place raw egg in beaker of white vinegar - Label and wrap in plastic wrap. Leave for 1-2 days. White shell will dissolve. 2. After previous wait time shell has dissolved. Remove egg with slotted spoon and rinse to remove vinegar. <chemical reaction has occurred. What chemicals were involved as reactants and products. 3. Observe outer membrane (touch and sight). Outer membrane (diff. from membrane around yolk) represents a cell membrane well (thin/flexible) (permeable to some materials). Place egg in 5% NaCL solution for 24 Hours. Describe egg after 24 hours. What has caused change in appearance. 4. Gently rinse egg. Place egg in distilled water for 24 hours. Describe egg after 24 hours. What causes appearance? 5. To retrieve egg cell slice open egg membranes, gently, let whites drip through spoon slots into 100 mL beaker. Attempt to remove whites without piercing yolk. 6. Place yolk into beaker and set aside membrane. |
Procedure #2-
Monosaccharide Indicator Standard Test: 1. Test For Glucose: In test tube mix: 2mL of a 2% glucose solution (a monosaccharide) with 2 mL of Benedict's Solution. Heat solution for 2 minutes in boiling water bath (100 mL in a 250 mL beaker at 100 C). Record color changes and times at which color changes. 2. Test for water (negative control): In test tube mix: 2 mL of deionized water with 2 mL of Benedict's Solution. Heat 2 mintues in boiling water bath (100 mL water in 250 mL beacker at 100 C). Record changes in color and tiimes of color change. Starch Indicator Standard Test: 1. Test for Starch: In test tube mix: 2 mL well-mixed starch suspension with .25 mL Lugol's Iodine. Gently swirl to mix (DO NOT HEAT). Record time and change in color. 2. Test for water (negative control): In test tube mix: 2 mL deionized water with .25 mL Lugol's Iodine. gently swirl to mix. (DO NOT HEAT). Record change in color and time. Protein Indicator Standard Test: CAUTION: Sodium hydroxide (NaOH) is a strong base, is caustic, and can burn. Wear goggles and gloves. Wipe spills immediately and thoroughly. Flush exposed surfaces with tap water. 1. Test for protein: Place 2 mL of gelatin (protein) solution in test tube. (Wearing goggles) add .5 mL of 10% NaOH and gently vortex to mix. Add .25 mL of 5% copper sulfate (CuSO4) and gently mix. The NaOH and CuSO4 mixture is called Biuret reagent. Mix well. Record color changes and times after 30 seconds. 2. test for water (negative): Place 2 mL de-ionized warer into test tube. Add .5 mL Biuret reagent and gently vortex to mix. Record color changes and times after 30 seconds. Lipid Indicator Standard Test: 1. Test for Lipids: Place |
Procedure #3:
1. Conduct each test while substituting each egg component to test for sugar, starch, protein, or fat. Only differing variable is subject tested. Do not add any standard solutions.
2. Record results of testing egg membrane, yolk (cell cytoplasm), and whites for all 4 molecules on another data set.
3.
1. Conduct each test while substituting each egg component to test for sugar, starch, protein, or fat. Only differing variable is subject tested. Do not add any standard solutions.
2. Record results of testing egg membrane, yolk (cell cytoplasm), and whites for all 4 molecules on another data set.
3.
Reflection:
Over all it was a pretty average lab. My partner and I worked well together and completed each experiment at a good pace. On the third day, though, a set-back from another assignment caused us to fall behind. The next day we were able to go into the lab and finish it up with no problems.
Over all it was a pretty average lab. My partner and I worked well together and completed each experiment at a good pace. On the third day, though, a set-back from another assignment caused us to fall behind. The next day we were able to go into the lab and finish it up with no problems.