Question 23M.1.HL.TZ1.19
| Date | May 2023 | Marks available | [Maximum mark: 1] | Reference code | 23M.1.HL.TZ1.19 |
| Level | HL | Paper | 1 | Time zone | TZ1 |
| Command term | Question number | 19 | Adapted from | N/A |
What is secreted by the pancreas for digestion in the small intestine?
A. Lipase to break bond between phosphate and fatty acid
B. Insulin to digest glycogen to glucose
C. Amylopectin to digest starch to maltose
D. Endopeptidase to digest proteins to peptides
[1]
D
The percentage of candidates answering correctly was lower than the guesswork level of 25% and the lowest on this paper. The discrimination index was also low, showing that weaker candidates were not the only ones to have answered incorrectly. Answer D wasn't ideally worded — it would have been better to state that endopeptidase digest peptides to shorter peptide, rather than proteins to peptides. The other answers were definitely incorrect, but in each case it was necessary to read them carefully to notice the error. Another possible reason for poor performance on this question was weak subject knowledge. Understandings in 6.1 of the core specify secretion of digestive enzymes by the pancreas into the small intestine, with guidance that amylase, lipase and endopeptidase should be included. Students are expected to know what reaction each of these enzymes catalyses, but this question showed that many did not.