lab 2aPurpose - indicator solutions to test for proteins, carbohydrates, and fats.
Materials - Eggs, 250 ml breaker, white vinegar, plastic wrap, slotted spoon, sodium chloride, distilled water, 100 ml beaker, 5 ml pipets, green pipet pump, 13x100 mm glass tubes, peg racks for 13x100 mm tubes, glucose, Benedict's solution, hot plate stirrer, test tube holder, soluble starch, Lugol's Iodine Solution, vortex mixer, gelatin, sodium hydroxide, cupric sulfate 5-hydrate, oil, Sudan IV, scalpel handles #4, scalpel blades #22, plastic trays data/resultsPart I
Day 1: -- Egg was placed in vinegar for 48 hours -- Bubbles visible on egg shell after 24 hours Day 2: --The chemical reaction that occurred was CaCO3 + CH3COOH ------> H2CO3 + H2O + CO2. The shell was dissolved. Day 3: -- We took the egg out of the vinegar and the shell had dissolved, membrane was translucent, egg looked yellowish -- Egg placed into salt water for 24 hours, salt seemed to draw water out of egg which got smaller Day 4: -- Egg was taken out of the salt water and put into deionized water for 24 hours, absorbed water and got bigger Part II Glucose Test: When heated, turned yellow at 15 seconds, then red-orange at 30 seconds - positive Starch Test: After 20 seconds turned black - positive Protein Test: After 30 seconds turned purple - positive Lipid Test: Turned orange - positive Part III Color Changes: Glucose -- Egg white: purple Egg yolk: gray and blue Egg membrane: blue and white Protein -- Egg white: purple Egg yolk: brown Egg membrane: no change Lipid -- Egg white: purple Egg yolk: orange Egg membrane: no change Starch -- Egg white: brown Egg yolk: orange Egg membrane: no change Reflection: This project was an enjoyable, hands on activity and I had a lot of fun with it. One thing I could have done better was stay more on task and focused on the activity instead of talking with friends. One thing I did well was completing everything on time. |
Procedure: Part I
Part II Monosaccharide Indicator Standard Test
1. Test for starch by mixing 2mL of well-mixed starch indicators with 0.25 mL of Lugol's iodine and mix (do not heat). Record results. 1. To test for water, mix 2 mL of deionized water with 0.25 mL of Lugol's iodine and mix (do not heat). Record results. Protein Indicator Test Test for proteins. Place 2 mL of gelatin in a test tube. Add 1 mL biuret solution. Record results after 30 seconds and repeat for water. Lipid indicator Standard Test Test for lipids: Place a drop of oil on a brown paper bag and let dry for 10 mins. hold up paper to light and record translucence. Do the same with water and record. Part III Molecular Composition of Egg Components Conduct each indicator test from part II but substitute each egg component to be tested. Do not add any standard solutions. Record the results for each of the egg components. Include numeric values for the color changes to rate the amount of change: 3 = very strong positive 2 = strong positive 1 = weak positive 0 = no color change (negative) |