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food lab report

Howard University
Uploaded: 3 years ago
Contributor: falabdul8664
Category: Biology
Type: Report
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Filename:   Food lab report (1).docx (30.05 kB)
Page Count: 8
Credit Cost: 1
Views: 44
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Transcript
Sample Food lab/ organic molecules BIOL141 Lab Background: There are five major macromolecules that human include in their diet to keep them healthy. In food lab, we will test for simple sugars, starch, lipid, protein, and Vitamin C. Two controls will be used (one negative control and one positive) to help us determine the unknown substance. We also used the pH scale to help us understand the enzyme’s job in slowing or speeding the chemical reactions in yeast. Goals: The goal of this lab is to identify the organic molecules found in human diet as well as to demonstrate the oxidative action of Vitamin C. We will also observe the catalase enzyme found in active yeast. Hypothesis: For activity one: I hypothesize that organic molecules (simple sugar, starch, lipids, protein, and Vitamin C) will test positive and change color when I add (Glucose, Iodide, Sudan IV, Albumin, and Indophenol) respectively. For activity two: I hypothesize that the unknown is going to be milk if it tests positive for: simple sugar, lipid, protein and negative for starch and Vitamin C. For activity three: I hypothesize that the catalase will work best when it takes place in room temperature. Procedure: Activity #1: For simple sugar test: Label two test tubes 1 and 2. Add 5 mL of water to both tubes. Add 10 drops of water to tube 1. Add 10 drops of 4% glucose solution to tube 2. Add 20 drops of Benedict solution to both tubes Heat for 3-5 minutes. Observe color change Record data For starch test: Label two test tubes as + and –. Add 5 mL of water to both tubes. Add 10 drops of water to tube +. Add 10 drops of 2% starch to tube -. Add 4 drops of iodine potassium iodide to tube +. Add 4 drops of iodine potassium iodide to tube -. Shake both tubes for 30 seconds. Observe color change. Record data. For lipid test: Label two test tubes 1 and 2. Add 5 mL of water to both tubes. Add 10 drops of water to tube 1. Add 10 drops of Sudan IV to tube 1. Add 10 drops of Sudan IV to tube 2. Look closely at the meniscus. Observe changes. Record observation. For protein test: Label two test tubes as + and –. Add 5 mL of water to both tubes. Add 10 drops of water to tube +. Add 10 drops of albumin to tube -. Add 20 drops of sodium hydroxide to both tubes. Add 20 drops of copper sulfate to both tubes. Shake both tubes for 30 seconds. Observe color change. Record data. For Vitamin C text: Label two test tubes 1 and 2. Add 5 mL of water to both tubes. Add 20 drops of Indophenol to both tubes. Add vitamin C solution by drop, count the number of drops until the solution becomes clear to tube 1. Using a plastic dropper, add the same number of drops with water to tube 2. Observe color change. Record data. Activity #2: Set up 5 test tubes on a rack Place 4 drops of food sample in each tube. Conduct simple sugar test on first tube: Combine sample with 10 drops of benedict solution. Place tube in hot bath for 3 min. Observe color change. Conduct starch test on second tube: Combine sample with 1 drop of iodine potassium iodide. Shake for 30 sec. Observe color change. Conduct lipid test on third test tube: Combine sample with 7 drops of Sudan IV. Shake for 30 sec. Observe color change. Conduct protein test on fourth test tube: Combine sample with 10 drops of sodium hydroxide and 10 drops of copper sulfate. Shake for 30 sec. Observe color change. Conduct Vitamin C test on fifth test tube: Combine sample with 4 drops of Indophenol. Observe color change. Activity #3: Label three test tubes as A, B, and C. Fill each tube with 9mL of H2O2 Place tube A in the refrigerator, B on bench top, and C in hot bath for 15 min. Connect balloon to tubes. Let all yeast full in the tube. Shake it gently. Wait for 1-2 min. Measure the balloon. Record data. Result section (data): Activity #1 data tables: Simple sugars Set up Tube 1 Tube 2 5 mL water10 drops water20 drops Benedict’s solution Heat 3-5 minutes 5 mL water10 drops 4% glucose solution20 drops Benedict’s solution Heat 3-5 minutes Type of control Water (negative) Glucose (positive) Results Stayed the same Turned Reddish- orange Starch Set up Tube + Tube - 5 mL water10 drops water4 drops of Iodine Potassium Iodide Shake for 30 seconds 5 mL water10 drops of 2% starch4 drops of Iodine Potassium Iodide Shake for 30 seconds Type of control Water (negative) Iodide (positive) Results The same (yellow) Turned black Lipids Set up Tube 1 Tube 2 5 mL water10 drops water10 drops of Sudan IV Shake for 30 seconds – look closely at the meniscus 5 mL water10 drops vegetable oil10 drops of Sudan IV Shake for 30 seconds – look closely at the meniscus Type of control Water (negative) Sudan IV (positive) results Dark red. Mixed Red. Float on top Protein Set up Tube + Tube - 5 mL water10 drops water20 drops of Sodium hydroxide20 drops of Copper sulfate Shake for 30 seconds 5 mL water10 drops albumin20 drops of Sodium hydroxide20 drops of Copper sulfate Shake for 30 seconds Type of control Water (negative) Albumin (positive) results Light blue. Purple. M Vitamin C Set up Tube 1 Tube 2 5 mL water20 drops Indophenol Add Vitamin C solution by drop – count the number of drops until the solution lightens/becomes clear 5 mL water20 drops Indophenol Using a plastic dropper, add water by drop – add the same amount of drops of water as you did with test tube 1 Type of control Water (negative) Indophenol (positive) Results The same color. Bleached Activity #2 data table: Molecule + - Simple sugars * Starch * Lipid * Protein * Vit C * Food: MILK Activity #3 data table: Tube Uninflated Inflated A/ cold 20 C 15 cm 16.7 B/ room temp 21 C 13.5 cm 15.8 C/ hot 50 C 15.5 cm 15.5 Result section (analysis): The positive control for reducing sugar resulted in an orange color, whereas the negative control did not affect the color. In the starch test, the tube with positive control turned black. In the lipid test, the oil float on top in the tube that contains Sudan IV. The protein test tested positive when adding Albumin, and that changed the color to purple. The vitamin test bleached when we added indophenol, whereas the color stayed the same in the tube that had water. For the second activity, we test an unknown. We tested the sample for what macromolecules it contains. The sample tested positive for simple sugar, lipid, and protein. The sample lacked starch and Vit C. We concluded that the sample is whole milk. For activity three, we measured the difference of dimeter of the balloon before and after the reaction. We concluded that the reaction of catalase would give the highest amount of O2 when it is at room temperature because it had the biggest difference. The uninflated was 13.5 and the inflated was 15.8 with a difference of 2.3 cm, whereas the cold tube changed in 1.7 cm, and the hot tube did not change. Discussion and conclusion: To test for macromolecules, we used two types of controls for each test. One control is positive (includes the substance of interest) and a negative control (the one with water). We expect no result from negative control, whereas in the positive control we expect a certain color change. When testing for organic macromolecules (simple sugar, starch, lipids, protein, and Vitamin C) with (Glucose, Iodide, Sudan IV, Albumin, and Indophenol) respectively, they all tested positive when adding the positive control. The observed color change indicates a positive result when sugar test turns red/orange, starch test turns black, lipid test has the oil float on top, protein test turns purple, vitamin C test bleaches. All these results support my hypothesis mentioned in the beginning of the report. The unknown sample tested positive for simple sugar, lipid, protein and negative for starch and Vitamin C. This result supports my hypothesis that the unknown is whole milk. Finally, the catalase reaction gave best result in producing O2 when it was in room temperature. This also support my hypothesis that the room temperature is the best environment for catalase reaction. During this lab, we added some more /less drops of certain controls to give us more obvious color change. As a general look, sugars are essentially for human brain to function properly. Starch is stored in plants cell for long term use. Lipids are important for animals’ body tissues. Protein is also crucial for body muscles. Lastly, Vitamin C is important for human for growth and development. References: Zacharof, M.P., and R.W. Lovitt. "International Journal of Chemical and Environmental Engineering: contemporary laboratory methods for separation and purification of organic macromolecules a review article." Cellular Polymers, vol. 31, no. 2, 2012, p. 119. Gale Academic OneFile, https://link.gale.com/apps/doc/A293351835/AONE?u=colu91149&sid=AONE&xid=ae779cab.

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