Lipid Group Proposal 1 v5.8

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Chemical Thinking Lipid Group Proposal 1 v5.8 | CHEM 151 LGP1 v5.8 6-3-23 1 Lipid Group Proposal 1 Your name: Your email: Your lab partner’s name(s): Your lab partner’s email(s): Your lab instructor’s name: Your lab section: 1. Session 1 Goals (1 pt) . In complete, well-written sentences, summarize in your own words the goals for this first session of the Lipid Project (not the entire Project – just the first session of the Project ) . In the first session of the Lipid Project the main goal is to develop and evaluate the separation techniques which does support a mass-based quantification of lipids present in the snack foods, isolate and quantify the lipids that are present in a sample of a snack food using differentiating solubility characteristics, and run tests to identify the presence of non-lipid food components that might interfere with lipid quantitation. 2. Food Component Two-Solvent Solubility Exploration Results (4 pts) . Clearly summarize in Table 1 below the key results from your implementation of the Food Component Solubility Testing Infographic on the three known food components (vegetable oil, protein powder, and starch). For each of the three known food components indicate where most of the component resides (which layer/solvent, or as an insoluble solid at the bottom of the aqueous layer) . Table 1. Vegetable Oil, Protein Powder, and Starch Two-Solvent Solubility Observations Component Vegetable Oil Protein Powder Starch Cyclohexane vs. NANOpure Water Vegetable separates into top layer, top and bottom become clear Protein powder separated into top layer, bubbly/cloudy top layer Starch in middle layer, cloudy/bubbly liquid Cyclohexane vs. 1 M HCl Vegetable oil separates into top layer, but both solutions appear clear after settled Protein powder separated into top layer, bubbly/cloudy top layer Starch in unknown layer, dissolves completely, clear on both layers Cyclohexane vs. 1 M NaOH Lipid separated completely into top layer the bottom layer appears cloudy Protein powder separates into middle layer, middle layer appears bubbly/cloudy Starch separates into unknown layer, dissolved completely Cyclohexane vs. 5 M NaCl Lipid separated into top layer solution becomes clear in both layers after settled Protein powder separates into middle layer, middle layer appears bubbly/cloudy Strach separates into the bottom layer, bottom layer is slightly cloudy Notes: All work must be very neat and organized . If you need to collect your thoughts, please use a separate sheet of paper. Proposals are a group effort . Please submit the completed document as a PDF to the Lipid Group Proposal 1 D2L DropBox before the scheduled end of lab. Always check to confirm the correct document/file has imported to the correct lab D2L Dropbox folder – no excuses. Submission to an incorrect Dropbox folder will be subject to a 1-point penalty. If you submit an unintended document, or need to update a submission, you can always resubmit so long as you are not past the deadline . If you submit the wrong document and fail to realize this until after the deadline, a resubmission cannot be accepted. So please be careful and always double check! This is performed in groups with a procedure basically identical to that of the Pigment Project . Hence, you should not exceed 30 - 35 minutes for this activity. You must be very well-organized and complete this exploration and Table 1 efficiently/expeditiously so that sufficient time to properly address the other activities remains.

Chemical Thinking Lipid Group Proposal 1 v5.8 | CHEM 151 LGP1 v5.8 6-3-23 2 3. Lipid Quantitation Exploration using the Practice Snack Food (6 pts) . From the results in Table 1 , identify the cyclohexane vs. aqueous solution (either NANOpure, 1 M HCl, 1 M NaOH, or 5 M NaCl) that best separates/isolates the lipids free of non-lipid solid components . Use this “best” solvent combination with the Lipid Gravimetric Analysis Infographic to quantitatively isolate the fat (lipid) from the practice snack food. The finely ground snack food mass should be in the 0.75 g range, with the vegetable oil control mass about 0.25 g. Use individual solvent (cyclohexane and the selected aqueous solution) volumes in the 2.5 mL range to give a total volume of roughly 5 mL. Complete Table 2 , which gathers the supporting raw data for the practice snack food lipid quantitation. Then complete Table 3 . You are NOT required to calculate an isolation correction factor or the percent fat by weight . Using the space below Table 3 , in well-written sentences clearly summarize the key results . Table 2. Practice Snack Food Lipid Quantitation Raw Data Practice Snack Food (Unknown) Mass (finely ground) Volume of Cyclohexane Volume of NaCl Beaker 1 Mass (m beaker 1 ) Unknown Isolate + Beaker 1 Mass (m 1 ) 0.749 g 2.5 ml 2.5 ml 65.41 g 66.20 g Vegetable Oil (Control) Mass Volume of Cyclohexane Volume of NaCl Beaker 2 Mass (m beaker 2 ) Control Isolate + Beaker 2 Mass (m 2 ) 0.249 g 2.5 ml 2.5 ml 74.73 g 74.98 g Table 3. Practice Snack Food Lipid Quantitation Results and Observations Unknown Isolate Mass (m ULI ) Control Isolate Mass (m CLI ) Observations 66.159 g 75.43 g The mass decreased due to all the cyclohexane being evaporated off and separated. After doing all the mixtures it was noticed that the vial with Cyclohexane NaCl and either protein or vegetable oil were the easiest to separate. It is strongly recommended to have one group member move on to the starch testing design/plan ( Part 4 ) while the other member monitors the cyclohexane being evaporated off from the Unknown and Control cyclohexane layers ( Part 3 ).

Chemical Thinking Lipid Group Proposal 1 v5.8 | CHEM 151 LGP1 v5.8 6-3-23 3 4. Testing for Starch in the Lipid Extract (3 pts) . Work out an iodine test (I 2 -KI solution) procedure to confirm a lipid isolate is free of starch . You may find the Iodine Test for Starch Technical Guide video helpful. In the space below, give your plan/procedure using iodine-potassium iodide (I 2 -KI) to ensure the absence of starch in your isolated lipid (this must be part of your Group Proposal 1 – so please be sure to incorporate your starch testing procedure in the group proposal below) . After completing the lipid extraction of both your control and your unknown snack food, to test whether or the solution has been isolated completely from starch, you must do an iodine test by adding a single drop of iodine to each beaker. If the drop turns a dark/blackish color, it has starch in the solution, if the iodine stays an orangish color the solution is starch free. To avoid running short on time, have one group member start the above starch testing design work while the other continues monitoring the evaporative removal of cyclohexane from the Unknown and Control cyclohexane layers of Part 3 .

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Chemical Thinking Lipid Group Proposal 1 v5.8 | CHEM 151 LGP1 v5.8 6-3-23 4 5. Group Proposal 1 (6 pts) . Write an initial plan (Group Proposal 1) to isolate and quantitate the fat (lipid) present in your assigned snack food using only the resources available in lab. That is, write out a procedure in outline form to isolate and quantify the fat (determine the percent fat by weight for your assigned snack food) that includes building and applying an isolation correction factor (see the Lipid Gravimetric Analysis Infographic ) and a test to confirm the lipid isolated is free of starch. Please NUMBER your procedural steps . Procedural Steps 1) Begin by collecting 0.25 g of your unknown snack, 0.75g of vegetable oil, and 5-10 ml of NaCl and cyclohexane. 2) Crush the unknown snack using a mortar and pestle 3) Grab two beakers and measure both of their weights. Record the results. 4) Grab a centrifuge tube and fill it with 0.25g of the unknown snack, 2.5 ml of NaCl, and 2.5 ml of Cyclohexane. 5) Fill another centrifuge tube with 0.75g of vegetable oil, 2.5 ml of NaCl, and 2.5 ml of cyclohexane> 6) Place both centrifuge tubes in the centrifuge and run it for 3 minutes. 7) Take the tubes out of the centrifuge tube carefully being sure not to re mix the solutions 8) Pipette of the top (lipid) layer of each centrifuge tube and place them into the two separate pre-weighed beakers. 9) Place the beakers onto the hot plate at 60-70 degrees for 6 minutes to burn off any excess cyclohexane in the lipids 10) After 6 minutes take the beakers off the hot plate and wait for them to cool 11) Measure the new mass of the beakers on the scale and record the weights 12) Take the weight of the lipid + the beaker and minus the weight of the pre weighed beaker, repeat this step for the second beaker. 13) After you have recorded the weights, use the iodine test (using the Iodine Test for Starch Technical Guide) to ensure both of your lipids are starch free 14) To apply the isolation correction factor, you have to divide the original mass of the control vegetable oil by the new mass of the vegetable oil. 15) Multiply the number you got from step 14 by the mass of your unknown you recorded after the experiment. 16) Finally, to calculate the fat percentage, take the number you got from step 15, divide it by the mass of the unknown snack you used before running the experiment, and times it by 100.