Chapter 3 / 5 short lessons
Membranes and transport
Use membrane structure to explain selective exchange, gradients and vesicle transport.
H1 Biology / 8876 / 2027 syllabus
What do you think?
A cell takes up a mineral ion although its concentration is already higher inside. Is simple diffusion enough?
Lessons
0 of 5 marked as readA fluid bilayer with many jobs
Explain the fluid mosaic model and the roles of its constituent biomolecules.
About 6 minBoundaries create useful conditions
Outline the functions of cell surface and internal membranes.
About 4 minDown a gradient: three passive routes
Explain simple diffusion, facilitated diffusion and osmosis across membranes.
About 6 minPay energy to build a gradient
Explain why active transport needs membrane proteins and an energy supply.
About 5 minMove bulk material in vesicles
Explain endocytosis and exocytosis as energy-requiring membrane processes.
About 5 minWhat you will be able to do
- Explain each component of the fluid mosaic model.
- Distinguish surface and internal membrane functions.
- Choose a transport mechanism using the substance and its gradient.