DP Chemistry (last assessment 2024)
Question 18N.3.hl.TZ0.11a
| Date | November 2018 | Marks available | [Maximum mark: 2] | Reference code | 18N.3.hl.TZ0.11a |
| Level | hl | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
18N.3.hl.TZ0.11a
The transport of oxygen around the body is essential for life.
(a)
A graph showing saturation of oxygen against partial pressure of oxygen is shown.
Explain the shape of the graph from 0 to 50 % saturation.
[2]
Markscheme
binding of oxygen/O2 «to one active site» affects shape of Hb/other active sites
OR
binding of one oxygen/O2 «molecule» affects binding of other oxygen/O2 «molecules» ✔
increasing affinity of Hb to oxygen/O2
OR
enhanced binding of «further» oxygen/O2 «molecules»
OR
cooperative binding ✔
