PSCI

• THE PLASMA MEMBRANE

  • Primarily composed of a lipid bilayer embedded with proteins
  • Usually has a consistency of an olive oil
  • Exhibits asymmetry
  • Represented by the “Fluid Mosaic Model”

  A) PHOSPHOLIPID

  B) CHOLESTEROL

  C) INTEGRAL PROTEIN

  D) GLYCOLIPID

  E) PERIPHERAL PROTEIN

  F) GLYCOPROTEIN

  
• THE PLASMA MEMBRANE FUNCTIONS

  • Compartmentalization
  • Selective transport
  • Biochemical activities
  • Cell to cell communication
• MEMBRANE LIPIDS

  • Phospholipids
  • Sphingolipids
  • Sterols

  
• MEMBRANE LIPIDS FUNCTIONS

  • Membrane fluidity
  • Affect protein activity
  • Cell messengers
• MEMBRANE CARBOHYDRATES

  • Glycoprotein - carbohydrates attached to proteins
  • Proteoglycans
  • Glycolipids - carbohydrates attached to phospholipid

  FUNCTIONS

  • Environmental interaction
  • Protein sorting
• MEMBRANE PROTEINS

  • Integral Protein
  • Peripheral Protein
  • Lipid Anchored Protein

  FUNCTION

  • Structural support
  • receptors
  • channels/transporters
  • enzymes
• Integral Protein

  • These proteins embedded within the cell membrane. Some may pass all the way through the membrane.
  • They help transport substances (like ions or molecules) across the membrane and play a role in cell communication.

  Think of them like:

  • A pencil stuck through a balloon. It goes through the membrane and sticks out on both sides.
• Peripheral Protein

  • These proteins sit on the surface of the membrane, either on the outside or the inside, but they don't go all the way through.
  • They assist with cell signaling and help maintain the cell's structure.

  Think of them like:

  • A sticker on the surface of a balloon. It doesn’t penetrate the balloon but is attached to it.