proteins

• extrinsic proteins -

  • on 1 side of bilayer
  • hydrophobic R-groups on surface
  • interact with phospholipid head
• intrinsic protein -

  • carrier protein ( changes shape allowing passive and active transport)
  • channel protein (allow movement of polar molecules and ions down conc gradient)
  • embedded in cell surface membrane
  • both layers
• creates pores which water can dissolve through and water soluble chemicals
• form channels in membranes which cmall charged molecules can fit
• receptor site for hormones
• structural support
• cell recognition
• carrier proteins transport molecules and ions across membrane by active transport and facilitated diffusion