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IB Biology HL B2.1.8 Selectivity in Permeability Questions

Practise matching molecule properties to membrane routes, from oestradiol crossing the phospholipid bilayer to fructose moving by facilitated diffusion.

Syllabus
First assessment 2025
Course
Biology HL
Level
HL

Exam points

  • Choose simple diffusion for small, non-polar solutes or facilitated diffusion for larger or polar solutes.
  • Compare both routes as passive, down-gradient transport, but only facilitated diffusion uses selective proteins.
  • Match oestradiol with the bilayer and fructose with facilitated diffusion in molecule-route tables.
  • Relate facilitated-diffusion rate to transport-protein abundance when comparing it with simple diffusion.

IB Biology HL B2.1.8 Selectivity in Permeability Questions question 1

[Maximum number: 1]

Cells use a variety of methods to move particles across membranes. What is a similarity between facilitated diffusion and active transport?

A

Both are carried out by proteins in the membrane.

B

Both move particles against the concentration gradient.

C

Both use ATP.

D

Both move non-polar ions across the membrane.

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