| Date | May 2012 | Marks available | 1 | Reference code | 12M.1.HL.TZ2.26 |
| Level | Higher level | Paper | Paper 1 | Time zone | Time zone 2 |
| Command term | Identify | Question number | 26 | Adapted from | N/A |
Question
The diagram shows the cross section of a plasma membrane.
What is found in area X?
A. Glycolipid
B. Glycoprotein
C. Polar amino acid
D. Non-polar amino acid
Markscheme
C
Examiners report
This was the third hardest on the paper and an excellent discriminator. Candidates were expected to identify the structure as a channel protein and deduce that polar amino acids would line the pore.
