DP Biology (last assessment 2024)
Question 19M.3.SL.TZ2.b
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.SL.TZ2.b |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Compare and contrast | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
19M.3.SL.TZ2.b
The diagram shows metabolic pathways for lactate in humans.
[Source: © International Baccalaureate Organization 2019]
Compare and contrast the possible metabolic pathways for lactate in hepatocytes and in mitochondria-rich tissue.
[2]
Markscheme
a. both produce pyruvate «from lactate»
OR
both produce CO2 and H2O «via acetyl CoA» ✔
b. hepatocytes produce glucose from lactate but mitochondria-rich cells cannot ✔
OWTTE – eg: “only hepatocytes produce glucose” would be acceptable.
Examiners report
Part (b) and (c) were well answered, the main error was confusing the hepatocytes with the Kupffer cells.
