Cell Membranes

• Phospholipid Structure

  • Negative, hydrophilic phosphate head
  • Two hydrocarbon chains / fatty acids
  • Glycerol molecule
• Intrinsic Proteins - Proteins span the whole width of the membrane e.g. carrier proteins and channel proteins
• Extrinsic Proteins - Proteins are confined to the inner / outer membrane, they are required for cell recognition and signaling
• Glycoproteins - Made up of a carbohydrate and protein. Are extrinsic proteins that act as recognition sites, and allow cells to attach and form tissues
• Glycolipids - made up of a carbohydrate bonded with a lipid. Glycolipids act as recognition sites, and help to maintain the stability of the cell membrane
• Cholesterol - Lipid that maintains the cells fluidity and prevents the cells from bursting.
• The cell membrane is fluid as the phospholipids are able to move in the membrane. the fluidity is maintained by cholesterol
• The cell membrane can be described as a mosaic as there is no fixed position for the proteins within the membrane