Question 20N.3.HL.TZ0.23d
| Date | November 2020 | Marks available | [Maximum mark: 3] | Reference code | 20N.3.HL.TZ0.23d |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Describe | Question number | d | Adapted from | N/A |
The graph shows the Bohr shift.
[Source: From The New England Journal of Medicine, Connie C.W. Hsia, Respiratory Function of
Hemoglobin, Volume 338(4):239–47. Copyright © 1998, Massachusetts Medical Society. Reprinted with permission
from Massachusetts Medical Society.]
Describe what happens to the hemoglobin from old or damaged red blood cells that are broken down.
[3]
a. hemoglobin (from broken red blood cells) taken up by Kupffer cells (in the liver);
b. hemoglobin broken down into heme and globin;
c. globin hydrolyzed/broken down to amino acids;
d. iron removed from heme group
OR
heme broken down to form bilirubin/bile pigment;
Do not accept red blood cells broken down into heme and globin.
The majority of candidates described the process correctly; some stated incorrectly that red blood cells, instead of hemoglobin, are broken down into heme and globin.
