Question 19M.3.HL.TZ1.c
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.3.HL.TZ1.c |
| Level | HL | Paper | 3 | Time zone | TZ1 |
| Command term | Suggest | Question number | c | Adapted from | N/A |
Lipase was extracted from the fungus Aspergillus niger and used to hydrolyse one of its substrates. This was repeated for an immobilized form of lipase. The graph shows how the enzyme activity varied at different pH and temperature levels.
[Source: adapted from Zdarta, J.; Klapiszewski, Ł.; Wysokowski, M.; Norman, M.; Kołodziejczak-Radzimska, A.; Moszyński, D.;
Ehrlich, H.; Maciejewski, H.; Stelling, A.L.; Jesionowski, T. Chitin-Lignin Material as a Novel Matrix for Enzyme Immobilization.
Mar. Drugs 2015, 13, 2424–2446.]
Based on these experimental results, suggest one advantage of immobilizing lipase.
[1]
a. it increases the range of temperature/pH that give high activity ✔
b. allows for commercial use in detergents ✔
Most candidates saw that the enzymes could work at a higher temperature and a broader range of temperature and pH values and were therefore able to achieve 1 mark. Few students could connect this to the industrial uses for enzymes. This was one of many instances in the paper where students’ inability to use precise language affected their scores. Specifically, students should be reminded that terms like “affect” and “change” do not communicate differences in data as well as words like “increase” and “decrease.”
