Macromolecule Lab Sheet

Objective: Determine whether specific macromolecules are present in food samples by performing chemical tests using substances called indicators. Background: Macromolecules is a large molecule. The four major macromolecules include carbohydrates, lipids, protein, and nucleic acids. Most macromolecules can be simple and multiple units. For example, a simple carbohydrate is glucose. Glucose in is disaccharide which is a multiple unit carbohydrate. Hypothesis: • If the sugar test is preformed, apple juice, gelation, soda, and crackers will show positive. • If the starch test is preformed, apple juice, canola oil, gelatin, crackers, and soda will show results for starch. • If the protein test is done, egg whites, crackers, and whole milk will be positive for protein. • If the lipid test is done, apple juice, canola oil, egg whites, crackers, gelatin, whole milk, and soda would have lipids. • If the acid/neutral/base test is preformed, apple juice and soda would be acid. Water would be neutral. The bases would then be canola oil, gelatin, egg whites, crackers, and whole milk. Materials: • Distilled water • Apple juice • Canola oil • Egg whites • Gelatin • Crackers • Whole milk • Sprite • Benedicts Solution • Test Tubes • Iodine solution • Water bath • Biuret solution • Brown paper • Universal solution • Pencil • Paper Procedures: Sugar Test: 1. Add 1 pipette of test solution with 1 pipette of Benedict Solution 2. Put in hot water bath for 1-2 minutes 3. If color changes, the solution has sugar Starch Test: 1. 1 pipette of solution mixed with 3 drops of Iodine solution 2. If color changes, solution is positive for starch Protein Test: 1. 1 pipette of test solution mixed with 5-10 drops of Biuret solution 2. If solution becomes pink/purple, the solution is positive for protein Lipid Test: 1. 2-3 drops of test solution onto brown paper 2. Sit and let solution dry 3. Hold the brown paper up to a light or window 4. If the test solution leaves a spot that lets light through this indicates a positive test for lipids Acid/Base Test: 1. Mix 3-4 drops of universal indicator to 1 pipette of test solution 2. Based on colors from the chart below, determine if test solution is acid, base, or neutral 3. Ph range Description Color <3 Strong Acid Red 3-6 Acid Orange/Yellow 7 Neutral Green 8-11 Base Blue >11 Strong Base Violate/Purple Variables: • The independent variable in the investigation is the test solutions • The dependent variable in the investigation are the results of the tests Constants: • The parts of the investigation that were kept constant were the same amount of test solution and indicators for each separate test Control: • The control of the investigation is water • Results: Observations Present in Tests Acidic/Basic/Neutral? Sample Distilled 7 Water Apple Juice Turned orange for <3 sugar test Canola Oil Egg Whites 7 Turned purple for 7 sugar test Gelatin 3-6 • Crackers Turned orange/yellow for sugar test 3-6 Whole Milk Turned pruple with yellow bottom for sugar test 3-6 Soda <3 Turned from green to orange during sugar test Positive Test Results: Analysis: In our hypothesis, for the Sugar test, we believed that apple juice, gelatin, soda and crackers would have sugars. Our hypothesis was almost right. Apple juice, gelatin, soda and crackers did have sugar. However, whole milk and egg whites did too. Our hypothesis for the Starch test where that apple juice, canola oil, gelatin, crackers, and soda would have starch. However, the solution that had starch was crackers. Water, apple juice, canola oil, egg whites, gelatin, whole milk, and soda did not have starch; therefore, our hypothesis was wrong. For the Protein test, we believed that egg whites, crackers, and whole milk would have proteins. Egg whites, whole milk did have protein. Canola oil also had proteins. Cracker; however, did not have any proteins based on the results. For the Lipids test, we predicted that apple juice, canola oil, egg whites, crackers, gelatin, whole milk, and soda would have lipids. Apple juice, canola oil, gelatin, and crackers did have lipids. However, egg whites, soda, and egg whites did not. Distilled water did not have sugar, proteins, starch, or lipids. The final test, the acidic/basic test, we predicted that apple juice and soda were acidic. Water was neutral, and canola oil, egg whites, gelatin, crackers, and whole milk was basic. Our results showed otherwise. Distilled water was neutral as we predicted. We; however, did not predict that canola oil and egg whites would also be neutral. Apple juice and soda turned out to be strongly acidic, a <3. Gelatin, crackers, and whole milk turned out to be acid, all being between 3-6 level of acidity. Conclusion: Our hypothesis, were mostly wrong; as shown in the Analysis. (To see hypothesis results, please refer to the Anaylis). Our results could have been affected by many things. When we were doing the sugar test, each of our tubes did not sit the exact amout of time, or in water the same amount. For the stanch test, each of the three drops that we put in the test solutions was a different amount. The same for the protein test. We may not have put the same amount of drops for each tube and each drop was a different size. This is also true for the lipid test. Each drop was a different size and each paper had a different amount of drops on it. For the Acidity test, the amount of universal solution we put in each test solution was slightly different every time. For all the tests, the amount of test solution that was put into the test tubes was different. Each time we pipetted, we had a different amount of liquid inside the pipette. The results, however, can be useful for people going on diets. They can see which food they don’t want to eat if they need to limit sugars, starch, and ect. Our test could have been improved by using more accurate measures to put in our test solutions and solvents. For example, using micropipettes or just pipettes with pumps would help with exact measurements. We could also have made sure to have exact times while we waited for things to dry, cook, or change colors.