| Date | May 2018 | Marks available | 1 | Reference code | 18M.3.hl.TZ2.11 |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Sketch | Question number | 11 | Adapted from | N/A |
Question
Hemoglobin contains an iron ion that can bind to oxygen as part of the process of respiration.
Hemoglobin’s oxygen dissociation curve is shown at a given temperature. Sketch the curve on the graph at a higher temperature.
Outline two differences between normal hemoglobin and foetal hemoglobin.
Markscheme
curve below original curve «showing lower affinity for oxygen» beginning at 0
Award mark if end of student curve does not finish at same location as original curve.
[1 mark]
Any two of:
foetal hemoglobin has higher affinity for oxygen «than normal hemoglobin»
foetal hemoglobin is less sensitive to inhibitors/2,3-bisphosphoglycerate/2,3-BPG/DPG «than normal hemoglobin»
foetal hemoglobin contains two gamma units instead of the two beta units found in adult hemoglobin
[2 marks]
