Question 17N.2.SL.TZ0.01e
| Date | November 2017 | Marks available | [Maximum mark: 2] | Reference code | 17N.2.SL.TZ0.01e |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Evaluate | Question number | e | Adapted from | N/A |
The elasticity and resilience of the lungs are mainly provided by the protein elastin. Degradation of elastin produces peptides called desmosines.
Desmosines in urine or blood plasma have been proposed as biomarkers of lung degradation. The relationship between urine desmosines, plasma desmosines and COPD severity in patients was assessed.
[Source: Reproduced with permission of the © ERS 2012. European Respiratory Journal Apr 2012, 39 (4) 839–845; DOI: 10.1183/09031936.00064611]
Elastin is also an important component of other tissues such as arteries and ligaments. Evaluate how these other sources of elastin could affect the interpretation of the biomarker as an indicator of COPD.
[2]
a. degradation of elastin from other tissues may have contributed to the results
b. there is no guarantee that the concentrations of desmosines measured came from the lungs
OR
difficult to assess how much lung elastin constitutes the total
c. overlapping ranges makes interpretation difficult
[Max 2 Marks]
