structure of plasma membrane

• Plasma membrane


  A gateway that allows certain substances to move into and out of the cell
• Main components of the plasma membrane

  • Phospholipid molecules
  • Protein molecules (e.g. channel protein, carrier protein)
  • Glycoproteins
  • Glycolipids
  • Cholesterol
• Fluid mosaic model


  A model used to explain the structure of the plasma membrane
• Fluid mosaic model

  • The components (phospholipids, proteins, etc.) are not static but always moving to form a dynamic, flexible structure
  • The components are scattered and embedded in the phospholipid bilayer, forming a mosaic pattern
• Phospholipid molecule


  Consists of a lipid part and a phosphate group
• Phospholipid molecule


  • Has a polar (hydrophilic) head and non-polar (hydrophobic) tails
  • The polar head is attracted to water, while the non-polar tails are repelled by water
• Arrangement of phospholipid molecules in the bilayer

  1. Polar heads face the extracellular fluid and intracellular fluid

  2. Non-polar tails face each other in the center of the bilayer
• The plasma membrane is composed of a phospholipid bilayer
• The phospholipid bilayer has two layers of phospholipid molecules
• The plasma membrane also contains other components like proteins, glycoproteins, glycolipids, and cholesterol