Lipid Group Proposal 2 v5

.docx

School

University Of Arizona *

*We aren’t endorsed by this school

Course

151L

Subject

Chemistry

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by JusticeBoulder8678

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

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version