2.1

• Plasma membrane


  The structure that allows movement of substances into and out of cells to maintain living processes
• Plasma membrane


  • Regulates the movement of substances across it
  • Semi-permeable, allowing only certain molecules or ions to pass through by simple diffusion
• Types of molecules in plasma membrane

  • Cholesterol
  • Carrier protein
  • Pore protein
  • Glycolipid
  • Glycoprotein
• Cholesterol


  Strengthens the plasma membrane and makes it more flexible but less permeable to water-soluble molecules
• Carrier protein


  Transports large molecules such as glucose, amino acids, and vitamin C across the plasma membrane
• Pore protein


  Allows small and water-soluble molecules such as ions to pass across the plasma membrane through passive transport
• Glycolipid


  A combination of lipids and polysaccharides that helps cell-cell recognition
• Glycoprotein


  A combination of proteins and polysaccharides that helps cell-cell recognition