GENBIO QUIZ2

• Movement of substances across a membranes without the use of energy.

  Passive Transport
• Examples of PASSIVE TRANSPORT.

  -Diffusion

  -Osmosis

  -Facilitated Diffusion
• Diffusion


  Net movement of solute substances from an area of HIGHER CONCENTRATION to an area of LOWER CONCENTRATION.
• Osmosis


  Movement of water
• Osmosis


  The diffusion of water molecules across a selectivley permeable membrane.
• The Tonicity of Solutions

  -Hypertonic Solution

  -Hypotonic Solution

  -Isotonic Solution
• Cell in a HYPOTONIC SOLUTION


  The solute concentration OUTSIDE THE CELL IS LOWER than inside the cell.
• Cell in a HYPERTONIC SOLUTION


  The solute concentration OUTSIDE THE CELL IS HIGHER than that inside the cell.
• Cell in a ISOTONIC SOLUTION


  The solute concentration is equal to that inside of the cell.
• What happens to a cell in a hypotonic solution?

  May bulge or even burst.
• What happens to a cell in a hypertonic solution?


  May shrivel and Die.
• What happens to a cell in a Isotonic solution?


  No water will flow from one membrane to another.
• Facilitated Diffusion


  -Movement of solute through protein channels.
• Facilitated Diffusion


  Water and Certain Hydrophilic solutes cross the membrane.
• Channel Proteins


  -naturally present in the cell membrane.

  -Open or close as they respond to stimuli.
• Carrier proteins


  Change in shape.
• Active Transport


  -Uses energy in moving solutes across a membrane by MOVING UP the concentration Gradient.

  -Requires the use of energy through CARRIER PROTEINS.

  -Movement of molecules: UNIDIRECTIONAL (1 DIRECTION)