1 / 9

Plasma Membrane

Plasma Membrane . Outer boundary of a cell Gatekeeper - controls what enters and leaves the cell. Selective Permeability. Only certain molecules pass through the membrane Factors affecting permeability: size solubility charge (ions or uncharged molecules). Phospholipid Molecule.

wade-fulton
Download Presentation

Plasma Membrane

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Plasma Membrane Outer boundary of a cell Gatekeeper - controls what enters and leaves the cell

  2. Selective Permeability • Only certain molecules pass through the membrane • Factors affecting permeability: • size • solubility • charge (ions or uncharged molecules)

  3. Phospholipid Molecule Cell membrane is made of phospholipids Glycerol Fatty acid PO43- Fatty acid

  4. Phospholipid Molecule

  5. Model of Plasma Membrane • Lipid Bilayer • Two layers of phospholipids Nonpolar Fatty acids Polar Phosphate group

  6. Lipid Bilayer • Polar phosphate group dissolves in water • Point toward the outside and inside of the cell (toward water) • Nonpolar fatty acids DO NOT dissolve in water • Point toward the middle of membrane

  7. Dynamic structure • Fatty acid tails wave back and forth • Phospholipids glide through bilayer • Cholesterol • Embedded in membrane • Rigid • Restrict phospholipid movement

  8. Membrane Proteins • Embedded throughout bilayer • Lie on inner or outer surface • Polar and nonpolar portions • Migrate

  9. Fluid Mosaic Model • Fluid-Components of membrane are constantly moving • Mosaic- random pattern of proteins Cell organelles have membranes with the “fluid mosaic” structure.

More Related