module 4

• Cell Membrane

  gatekeeper of the cell
• Functions of Cell Membrane

  • seperates the content
  • semipermeable membrane
• Components of Cell Membrane

  • Phospolipids - made up of a phospholipid bilayer which consists of a hydrophilic (head) and hydrophobic (tail)
  • Cholesterol - keeps the cell membrane from becoming too stiff
  • Integral Proteins
  • Peripheral Proteins
  • Carbohydrates
• Glycolipids

  help the cell to become familiarized with other

  cells around them
• • Structural Protein - gives cell support and shape
  • Receptor Protein - helps the cell in communicating with the outside environment
  • Transport Protein - transport molecules across cell membrane
  • Glycoproteins - helps in cell to cell communication and transport of molecules
• Transport Proteins

  • Channel - allow water molecules to pass through
  • Carrier - binds with specific ions
• • Passive Transport - does not require energy/higher to lower
  • Active - requires energy/lower to higher
• Passive Transport

  • Diffusion - higher to lower concentration

  Examples

  • food coloring in water
  • tea bag in a hot water
  • spraying of perfume
• Passive Transport

  • Osmosis - diffusion of water

  Examples

  • raisins soaked in water
  • wrinkled fingers
  • watering plants
• Passive Transport

  • Tonicity - describes how the volume of the cell changes as a result of osmosis
  • Osmolarity - describes the total solute concentration of the solution
• • Hypertonic - shrink
  • Hypotonic - burst
  • Isotonic - balance
• Facilitated Diffusion

  happens when diffusion is aided by transport proteins
• Active Transport

  • Primary - dependent on ATP/(Na+ - K+ ATPase) is one the important activities within the animal cells
  • Secondary - does not require ATP/(typically Na+ or H+)
• Secondary Transport

  A) uniport

  B) antiport

  C) symport