Membrane Transport

• Simple Diffusion:

  • particles flow right through the barrier without any complications
  • happens with f.e. CO2
• Protein Channel (Facilitated Diffusion):

  • An open protein channel that allows particles that are small enough to flow through it.
  • This type of membrane transport is only meant for water
• Carrier Protein (Facilitated Diffusion):

  • The carrier protein is open towards the exterior and allows the particles to flow in
  • once the particles are in the carrier protein, it closes off towards the outside and allows the parts to flow inside the cell.
• Active Transport (Not Diffusion!):

  • similar to a carrier protein, but needs energy to be activated, which it gets through the ATP
  • the ATP transforms to ADP once attached to the "channel" and releases energy in the process. that energy opens the channel