Lipid Group Proposal 2 v5.7

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Chemical Thinking Lipid Group Proposal 2 v5.7 | 1 Lipid Summary and Group Proposal 2 Your name: Brock Dale Your email: brockdale@arizona.edu Your lab partner’s name(s): Adilson Inacio, Ashutosh Dayal Your lab partner’s email(s): aginacio@arizona.edu, ashutoshdayal@arizona.edu Your lab instructor’s name: Paige Sandoval Your lab section: 002C All work must be veryneat and organized . If you need to collect your thoughts, please use a separate sheet of paper. Proposals are a groupeffort . Please submit thecompleted document asa PDF to the LipidGroupProposal 2 D2LDropBoxbeforethescheduled end of lab. Alwayschecktoconfirmthecorrect document/file has imported to the correct lab D2LDropbox 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 thewrongdocument andfail torealizethisuntil afterthedeadline, aresubmissioncannot beaccepted. Sopleasebecareful andalwaysdoublecheck! 1. Session 2 Goals (1 pt) . In complete, well-written sentences, summarize in your own words the goals for this second session of the Lipid Project (not the entire Project – just the second session of the Project ). The goal for this second lipid project session is to use the first lab's skills, which is to evaluate the separation techniques which support a mass-based quantification of lipids present and implement it again. We separate the lipids from the snack food we got (potato chips) using cyclohexane, then centrifugate and heat it. Using iodine to determine if starch is present in the given snack food. 2. Implementing Group Proposal 1: Raw Data, Observations and Results (3.5 pts). Complete Table 4 , which gathers the supporting raw data for your first assigned snack food lipid quantitation. Then finish Table 5 . In the space below Table 5 , clearly report in complete well-written sentences: 1) the iodine-potassium iodine (I 2 -KI) test observations and results for this isolated lipid and the positive and negative test controls concurrently run, 2) what the test results indicate about your first assigned snack food lipid isolate, and 3) how the results were interpreted to arrive at the above stated claim (give the reasoning behind the conclusion as to what the starch test is saying about your assigned snack food lipid isolate). Table 4. Assigned Snack Food (QF6) Lipid Quantitation Raw Data Assigned 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 ) 0.751 g 2.5 ml 2.5 ml 75.54 g 76.291 g Vegetable Oil (Control) Mass Volume of Cyclohexane Volume of NaCl Beaker 2 Mass (m beaker 2 ) Control Isolate + Beaker 2 Mass (m 2 ) 0.253 g 2.5ml 2.5ml 68.95 g 69.203 g Table 5. Assigned Snack Food (QF6) Lipid Quantitation Results and Observations Unknown Isolate Mass (m ULI ) Control Isolate Mass (m CLI ) Observations 0.611 g 0.401 g The control isolate mass is larger than our original control mass, meaning that there must have been some remaining cyclohexane present after being taken off the hot plate. The iodine test showed an orangish red droplet in the lipid. This means that there is no starch present in the lipid. This is because if there was starch present in the lipid, then the droplet/solution would have turned black after doing the iodine test. CHEM 151 LGP2 v5.7 6-3-23

Chemical Thinking Lipid Group Proposal 2 v5.7 | 1 3. Implementing Group Proposal 1: Assigned Snack Food Isolation Correction Factor and Percent Fat by Weight (3 pts) . Present in a highly organized manner the isolation correction factor and percent fat by weight calculations for your assigned snack food based only on Tables 4 and 5 . Clearly state symbolically the equation(s) being used, then substitute in actual values, and finally give the results. Be certain all the calculations are presented in complete detail with correct units . Fc = Mass oil control (original) / Control Lipid Isolate Mass Fc = 0.253 g / 0.401 g = 0.6309 Mass of lipid = Fc * Unknown lipid Isolate mass Mass of lipid = 0.6309 * 0.611 g = 0.3855 g Percentage fat by weight = Mass of lipid/ Mass of Snack food * 100% Percentage fat by weight = 0.3855 g / 0.751 g * 100% = 51.329% 4. Lipid Quantitation “Optimization” of the Assigned Snack Food (3.5 pts) . Considering the results in Tables 4 and 5 , propose another solvent volume in the 2 - 3.5 mL range likely to improve the isolation (maximize the fat yield while minimizing the presence of non-lipid food components in the lipid isolate). The finely ground snack food mass should remain at roughly 0.75 g, with the vegetable oil control mass about 0.25 g. Hence, you are just selecting an alternate volume (for cyclohexane and the aqueous solution) that must remain in the 2 - 3.5 mL range to give a 4 - 7 mL total volume. For example, if you employed 2.5 mL of cyclohexane and 2.5 mL of aqueous solution for your GroupProposal 1 , then based on the results ( Tables4 and 5 ), you might try 2 mL each for the two volumes, or perhaps 3.5 mL each, etc. You are conducting another trial to see if a different cyclohexane/aqueous solution volume improves the isolation – basically a simplified (because of time limits) optimization. Complete Table 6 , which gathers this “optimization” raw data. Then finish Table 7 . In the space below Table 7 , clearly report in complete well- written sentences: 1) the starch test observations/results for the positive and negative controls and the “optimization” isolated lipid, 2) what the test results indicate about your “optimization” lipid isolate, and 3) how the results were interpreted to arrive at the stated claim (the reasoning behind the conclusion of what the starch test says about your “optimization” assigned snack food lipid isolate). Table 6. Assigned Snack Food (QF6) Lipid Quantitation “Optimization” Raw Data Assigned 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 ) 0.752 g 2ml 2ml 106.315 g 107.067 g Vegetable Oil (Control) Mass Volume of Cyclohexane Volume of NaCl Beaker 2 Mass (m beaker 2 ) Control Isolate + Beaker 2 Mass (m 2 ) 0.25 g 2ml 2ml 96.881 g 97.131 g Table 7. Assigned Snack Food (QF6) Lipid Quantitation “Optimization” Results and Observations Unknown Isolate Mass (m ULI ) Control Isolate Mass (m CLI ) Observations 0.491 g 0. 213 g The masses are the smaller than the original masses which is better than the first run. The first run would most likely be better because there was no starch at all after doing the iodine test, although the results may be a little unclear because there was a very small amount of lipid remaining to test with iodine after the first run. The iodine test showed a little bit of black spots in the bottom of the beaker but mostly orangish – red color. This means that there was a little bit of starch remaining in the lipid after the isolation. If there was a lot of CHEM 151 LGP2 v5.7 6-3-23

Chemical Thinking Lipid Group Proposal 2 v5.7 | 1 starch present the droplet would be much blacker, but if starch wasn’t present at all, there wouldn’t be any black spots at all. 5. Lipid Quantitation “ Optimization”: Assigned Snack Food Isolation Correction Factor and Percent Fat by Weight (3 pts) . Present in a highly organized manner the isolation correction factor and percent fat by weight calculations for your assigned snack food based only on Tables 6 and 7 . Again, clearly state symbolically the equation(s) being used, then substitute in, and finally give the results. Remember, the calculations must be complete . Fc = Mass oil control (original) / Control Lipid Isolate Mass Fc = 0.25 g / 0.213 g = 1.174 Mass of lipid = Fc * Unknown lipid Isolate mass Mass of lipid = 1.174 * 0.491 = 0.5764 g Percentage fat by weight = Mass of lipid/ Mass of Snack food * 100% Percentage fat by weight = 0.5764 g / 0.752 g * 100% = 76.649% CHEM 151 LGP2 v5.7 6-3-23

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Chemical Thinking Lipid Group Proposal 2 v5.7 | 1 6. Group Proposal 2 (6 pts) . Given the results reported in Tables4- 7 above, identify the best volume for your “final procedure.” If necessary, incorporate any last- minute corrections (to address remaining problems) in your “final procedure.” Include two (2) replicate (repeat) runs of your “final procedure” in your plan to enable calculation of the average percent fat by weight for your assigned snack food. Since these are replicate runs with identical solvent volumes and roughly the same sample (unknown) masses, you can run a single vegetableoilcontrol and calculate a single isolationcorrectionfactor that will apply to both runs. Also, include a test to confirm the lipid isolates are free of starch. Thus, you are writing a “final plan” in outlineform to determine the assigned snack food percent fat by weight two (2) times by running two (2) finely ground samples and one (1) vegetable oil control with the solvent volumes fixed and the unknown masses roughly the same, and that includes a starch test. Keep in mind you will have only an hour in Session 3 to implement this – so your “final plan” must run the two replicate samples and oil control concurrently (NOT one after another). PleaseNUMBERyourproceduralsteps. Procedural Steps The optimized final volumes for the “final procedure” were concluded to be 2.5 ml of NaCl and Cyclohexane, because the first run had no presence of starch after the iodine test and the second run had presence of starch. For the final procedure we will try to minimize the error of the control isolate mass by being more careful with the steps to ensure we get a good isolation correction factor value. 1) Begin by collecting 0.150 g of your unknown snack, 0.50 g of vegetable oil, and 10-15 ml of NaCl and cyclohexane. 2) Crush the unknown snack using a mortar and pestle 3) Grab three beakers and measure both of their weights. Record the results. 4) Grab two centrifuge tubes and fill them each with 0.75g of the unknown snack, 2.5 ml of NaCl, and 2.5 ml of Cyclohexane. 5) Fill another centrifuge tube with 0.25g of vegetable oil, 2.5 ml of NaCl, and 2.5 ml of cyclohexane 6) Place all three 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 three 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 other two beakers. 13) After you have recorded the weights, use the iodine test (using the Iodine Test for Starch Technical Guide) to ensure both of your unknown lipid isolates are starch free, you do not have to test your control isolate. 14) To apply the isolation correction factor, you must divide the original mass of the control vegetable oil by the new mass of vegetable oil. 15) Multiply the number you got from step 14 by the mass of your unknown you recorded after the experiment. 16) Repeat step 15 for the second unknown isolate value. 17) 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. 18) Repeat step 17 for the second unknow n isolate value. 19) To calculate the average fat percentage weight of the two “final procedure” optimized runs, percentages from step 17 and 18, and divide them by 2 to get the average fat percentage weight of your unknow n snack. CHEM 151 LGP2 v5.7 6-3-23