Lab 3 Degradation and Protein Analysis Questions 20 Points Your Name Sara Mlodik Lab Partners Lab Date Bench 7 04 23 2026 Ana Toscano Navya Sriram Shreya Menon Giulia Scimonelli You will turn in one report per team online You will receive a team grade You will need the results you found in Lab 2 to make some calculations You may need to consult the literature to answer some of these questions cite all sources used PART 1 1 Data record 1 pt a Day 35 Weight of all conditions Crosslinking Solution Degradation Solution Neutral water Stomach mimic 1 2 Non Crosslinked Sample Crosslinked GTA Sample ID Gel 1 Weight Gel 3 Gel 2 Ave StDev ID Gel 1 Weight Gel 2 Gel 3 Ave StDev 0 462 0 374 0 256 0 364 0 103 0 651 0 633 0 736 0 673 0 05 0 905 0 865 0 849 0 873 0 029 0 325 0 666 0 290 0 427 0 208 4 5 b This is considered your starting dry weight of the crosslinked and non crosslinked gels Weigh the gels you put in a weigh boat to dry in Lab 2 ID Gel 1 Weight Gel 3 Crosslinked GTA Sample Non Crosslinked Sample Samples left to dry in Lab 2 Degradation Solution Dry samples not degraded c Day 35 Dry weight of all conditions after degradation we provided these numbers for you After crosslinked and non crosslinked gels were placed into water or stomach mimic we dried them and weighed them for you Ave StDev 0 121 0 065 0 104 0 097 0 029 Ave StDev ID Gel 1 0 103 0 119 0 087 0 103 0 016 Weight Gel 2 Gel 2 Gel 3 3 6 Degradation Solution ID Non crosslinke ID Crosslinked GTA Neutral Water 1 Stomach 2 d 0 060 g 0 037 g 4 5 0 069 g 0 062 g d Day 35 Gel observations after being in water or stomach mimic in a few words describe the following 2 pts Surface characteristics Observed stiffness mechanical properties Visual characteristics Approximate size diameter Condition Non crosslinked Neutral Water pH 7 Stomach pH 4 Crosslinked GTA Larger sticky elastic and smoother looking similar but a little littler in shade than the day one About 1 5cm in diameter More stiff more still elastic color light orange ish color size looks similar About 2cm in diameter Same color larger more transparent not as sticky less stiff less brittle shinier About 2cm in diameter Turned pink more flexible larger less sticky transparent About 2 2cm in diameter 2 Calculate the rate of degradation for each gel condition by comparing the average wet weight from Day 35 to the starting wet weight at Day 0 from Lab 2 Be sure to show all of your work for at least one calculation Describe any sources of error that might be present in this method Remember ID 1 is your control 2 pts Degradation Solution ID Non crosslinked ID Crosslinked GTA Neutral Water 1 61 39 Stomach 2 92 29 4 5 1 39 1 15 Degradation Day 0 wet weight Day 35 wet weight Day 0 wet weight x 100 Neutral Water Non crosslinked 0 417 0 673 0 417 x 100 61 39 A potential source of error is that the gels may absorb more water over time resulting in a gain in weight This indicates that the degradation percent calculated does not accurately reflect the true degradation of the sample but they reflect changes in water absorption Another source of error is the inconsistency in the amount of blotting for each sample If water was removed less effectively from the sample it would result in a greater measured weight This would underestimate the degradation percent calculated compared to the actual value 3 Calculate the rate of degradation for each gel condition by comparing the average dry weights from Day 35 Compare the numbers provided for you for degraded samples that have been dried table 1c to the dry weight samples not degraded you weighed today table 1b Be sure to show all of your work for at least one calculation 1 pt Degradation Solution ID Non crosslinked ID Crosslinked GTA Neutral Water 1 Stomach 2 41 74 64 07 4 5 28 8 36 08 Degradation Dry weight not degraded Dry weight after degradation Dry weight not degraded x 100 Neutral Water Non crosslinked 0 103 0 06 0 103 x 100 41 74 4 Discuss your gelatin degradation based on your observations relate size and condition to degradation amount in 1d 1 pt Based on the visual observations the non crosslinked gels appeared to degrade more than the crosslinked gels In neutral water the non crosslinked gel became larger more transparent shinier less stiff and less brittle suggesting that it absorbed more water and lost some structural integrity In the stomach mimic condition the non crosslinked gel became even larger more flexible and transparent which supports greater degradation and swelling under acidic conditions The crosslinked gels generally maintained more structure Even though they became sticky or elastic they stayed smaller and stiffer compared to the non crosslinked gels This suggests that GTA crosslinking helped preserve the gelatin network and reduced degradation The stomach mimic crosslinked gel still changed color and became somewhat elastic but it appeared more intact than the non crosslinked stomach sample Overall larger size softer texture and increased transparency were associated with higher degradation especially in the non crosslinked stomach condition 5 Discuss the degradation results based on your calculations in 2 and 3 what conclusions can you draw Be specific how does each condition affect degradation Must consider pH and crosslinking How does the experimental error factor into your conclusions Cite any sources used 3 pts Calculations show that acidic pH increased degradation while GTA crosslinking reduced degradation The non crosslinked gels degraded more than the crosslinked gels in both conditions In wet weight calculations non crosslinked gels showed larger changes in neutral water and stomach mimic compared to crosslinked gels The dry weight results showed the same trend with the highest degradation in the non crosslinked stomach mimic sample The stomach mimic condition caused more degradation than neutral water likely because the lower pH weakened the gelatin structure Crosslinked gels degraded less because GTA helped stabilize the gelatin network Experimental error may have affected the wet weight results because gels absorbed different amounts of water and may not have been blotted equally Therefore the dry weight results are likely more reliable for measuring true degradation Overall low pH increased degradation and crosslinking protected the gels from breaking down 6 Calculate the initial swelling ratio for each gel condition how hydrated were they at Day 0 Compare the average dry weights you measured on Day 35 to
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