A-LevelBiologyCell membranes and transport9700/12 · Feb/Mar 2025 · Q171 Mark
The graph shows how the rate of facilitated diffusion of substance X across a cell surface membrane changed as the concentration of substance X increased. All conditions, except for the concentration of substance X, were kept constant. Temperature was maintained at 15°C. [Figure 17.1] Which statement about the rate of facilitated diffusion is correct?
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
AThe rate of facilitated diffusion of substance X at Q will increase if the temperature is increased to 20 °C.
BThe rate of facilitated diffusion of substance X at P will increase if the concentration of ATP is increased.
CThe rate of facilitated diffusion of substance X at Q will increase if the concentration of substance X is increased.
DThe rate of facilitated diffusion of substance X at P will increase if the length of time over which the rate is measured is increased.
✓ Correct answer
A: The rate of facilitated diffusion of substance X at Q will increase if the temperature is increased to 20 °C.
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