Cell Transport

• Cell transport


  The process of how things move in or out of the cell through the cell membrane
• Cell transport categories

  • Passive transport
  • Active transport
• Passive transport

  An automatic process that doesn't require any input of energy
• Diffusion


  A passive process in which particles move either into or out of the cell from an area of higher concentration to an area of lower concentration
• No energy is required for diffusion to happen
• Active transport

  Particles move from an area of lower concentration to an area of higher concentration
• Active transport

  Particles move against the concentration gradient
• Energy is required for active transport to occur
• An important example of active transport is seen in heart muscle cells
• For heart muscle cells to work

  Certain molecules have to move from an area of low concentration to an area of high concentration
• Active transport

  • Requires energy
  • Particles move against the concentration gradient
• Passive transport

  • Automatic process
  • Doesn't require energy
• Passive transport


  Particles move through the cell membrane from an area of higher concentration to lower concentration without the use of energy
• Passive transport

  Movement along the concentration gradient without the use of energy
• Types of passive transport

  • Diffusion
  • Osmosis
  • Facilitated diffusion
• Diffusion

  Particles move from an area of high concentration to low concentration
• Solution


  A liquid with something dissolved in it
• Solute


  The dissolved substance in a solution
• Semi-permeable membrane


  A barrier through which only certain sized particles can pass freely
• Diffusion often occurs across the cell membrane

  Diffusion can happen with or without a semi-permeable membrane
• Diffusion

  Particles move from an area of high concentration to low concentration until equilibrium is reached
• Equilibrium is achieved when both sides of the container have about equal numbers of solute particles
• Diffusion is a natural process that doesn't use any energy
• Example of diffusion

  • Spraying air freshener in a room and people farther away eventually smelling it as the scent spreads
• Osmosis

  Diffusion of water through the cell membrane
• Osmosis is passive and doesn't require energy
• Equilibrium in osmosis means the proportion of water to solute particles is about the same on both sides of the membrane
• Facilitated diffusion

  Molecules diffuse through specialized protein channels in the cell membrane
• Facilitated diffusion works naturally without added energy
• Facilitated diffusion generally happens with particles a bit larger than those that can seep through the cell membrane's phospholipid layers
• Facilitated diffusion is when particles move from high concentration to low concentration
• Passive transport types are diffusion, osmosis, and facilitated diffusion
• 3 Types of solution

  • Isotonic solution
  • Hypotonic solution
  • Hypertonic solution
• Isotonic Solution

  number of solutes in fluid = number of solute in cell
• Hypertonic solution

  solution contains a higher number of solutes than the cell, solutes move in to the cell and water moves out.
• Hypotonic solution

  solution contains a lower number of solutes than the cell. results in cell swelling or expanding.
• Active transport

  Particles move from an area of low concentration to high concentration, also known as moving against the concentration gradient. Requires energy
• Passive transport

  Like a ball naturally rolling down a hill
• Active transport

  Opposite of passive transport, requires energy to move particles against the concentration gradient
• Cells requiring active transport

  • Heart muscle cells responsible for making the heart beat