Facilitated Diffusion and Active Transport

HideShow resource information
  • Created by: Jasmine
  • Created on: 19-02-16 16:16
View mindmap
  • Facilitated Diffusion and Active Transport
    • Facilitated Diffusion
      • Moves particles down a concentration gradient (higher to a lower concentration)
        • Does not use energy
      • Carrier Proteins
        • Move larger molecules (glucose and amino acids)
          • Can be polar molecules and ions
        • 1) large molecule attaches to a carrier protein binding site in the plasma membrane
        • 2) Then protein changes shape
        • 3) Releases the molecule on the opposite side of the membrane where there is a lower concentration of them molecules
      • Channel Proteins
        • Form pores in the membrane for smaller ions and polar molecules to diffuse through down a concentration gradient
        • 1) Move from a high concentration of charged particles
        • 2) Down the channel protein, across the plasma membrane
        • 3) Into the area where there is a lower concentration of charged particles
    • Active Transport
      • Uses energy to move molecules and ions across the plasma membrane- against a concentration gradient
      • Involves carrier proteins
        • Same as carrier protein but energy is used (ATP) to move the solute against the concentration gradient
    • Endocytosis
      • Largest molecules- eg proteins, lipids and some carbohydrates
      • Cell surrounds substance with a part of their plasma membrane
        • Pinches off and forms a vesicle
      • Processes uses energy (ATP)
    • Excocytosis
      • Substances eg hormones need to be released from the cell
      • Vesicles pinch off from Golgi Apparatus sacs and move to the plasma membrane
        • Release their contents outside the cell
          • Some are not released so they go straight to the plasma membrane
      • Process uses energy (ATP)


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Biological Membranes resources »