Date | May 2019 | Marks available | 1 | Reference code | 19M.1.HL.TZ2.9 |
Level | Higher level | Paper | Paper 1 | Time zone | Time zone 2 |
Command term | Determine | Question number | 9 | Adapted from | N/A |
Question
The graph shows the activity of an enzyme at different temperatures.
[Source: © International Baccalaureate Organization 2019]
What does the dashed line in the graph represent?
A. Increasing temperature increases substrate concentration.
B. Increasing temperature affects the active site.
C. Increasing temperature increases the rate of reaction.
D. Increasing temperature decreases the movement of particles.
Markscheme
B
Examiners report
This question discriminated very well and was easy. The graph does not have values for temperature, therefore it is not showing that temperature starts at 0 ºC. An increase in temperature with modify the tertiary structure of the protein, affecting the active site. At the same time the increase in temperature increases Brownian movement, increasing the chances of collision between enzyme and substrate.