Cell Membrane Structure

• Function of cell membrane

  1. Separate intracellular and extracellular fluid, also controlling entry and exit of substances
  2. Maintain high concentration of materials within cell
  3. Enables cell-to-cell communication
  4. Allows cells to sense their environment
• Cell Membrane structure (Fluid Mosaic Phospholipid Bilayer Model)

  1. Two layers of phospholipid molecules, while other molecules like carbohydrates, cholesterol, and proteins are scattered throughout membrane
  2. Hydrophilic phosphate head on the exterior, hydrophobic fatty acid tail in the interior, this makes the membrane semi-permeable
  3. Carbohydrates attached to glycoproteins and glycolipids on the outer surface help with adhesion and recognition of hormones, viruses, and antibodies
• Cell membrane molecules are "fluid", meaning they can move between layers
• Protein channels help impermeable substances cross the membrane by forming open pores
• Types of membrane proteins

  1. Transmembrane or integral proteins
  2. Peripheral or surface proteins
• Transmembrane or integral proteins allow the transport of materials
• Peripheral or Surface proteins allow for cell-cell communication
• Functions of transmembrane or integral proteins

  1. transport channels
  2. act as enzymes
  3. cell-cell communication
  4. signal transduction
  5. connecting cells
  6. act as attachments to cytoskeleton and extracellular matrix