Question 23M.2.HL.TZ1.a
| Date | May 2023 | Marks available | [Maximum mark: 2] | Reference code | 23M.2.HL.TZ1.a |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Draw | Question number | a | Adapted from | N/A |
Draw one phospholipid molecule on the diagram to show a possible position in the membrane.
[2]
phospholipid shown with circular head and 2 tails;
e.g.
[Source: Material from: Stauch, B., Johansson, L.C., McCorvy, J.D.,
et al., Structural basis of ligand recognition at the human MT1
melatonin receptor, published 2019, Nature, reproduced with
permission of SNCSC.]
phospholipid shown in either the upper or lower half of the membrane only with its head at the margin of the membrane and tails towards centre;
Accept answers with two or more phospholipids shown, as long as all are correct.
There were complaints from some teachers about the diagram. Apart from the label showing how the membrane was represented, the diagram was unlabelled to avoid burdening candidates with extra unnecessary detail. All the information needed to answer the question was included in the text at the start.
A mark was awarded for representing a phospholipid in the standard way with a circle and two lines and another mark for showing it in the correct position in the bilayer. Approximately equal numbers of candidates scored 0, 1 and 2 marks.
