Movement across membranes

Subdecks (5)

Cards (27)

  • We say that membranes are selectively permeable as they act as a barrier to most substances: allows materials to be concentratein cells, excluded, or separated from outside environment (eukaryotic also compartmentalise inside organelles)
  • Molecules need to be able to enter and exit cells, there are 5 main ways substances can move across a cell membrane:
    1. Simple Diffusion
    2. Facilitated Diffusion
    3. Active Transport
    4. Osmosis
    5. Endocytosis/Exocytosis
  • ATP in bulk transport: Provide energy for the vesicle movement along cytoskeleton microtubules (via motor proteins) and help fuse vesicle and plasma membrane together