Active and Passive Transport

• Diffusion is the random movement of particles from an area of high concentration to an area of low concentration down a concenration gradient until the particles are evenly distributed.
• Diffusion is a passive process
• The rate of diffusion depends on temperature, surface area, distance, pressure and solubility
• What are ways to improve diffusion rate

  • maintaining a steep concentration gradient
  • having a large surface area
  • minimizing the distance molecules have to travel
• Osmosis is the movement of water particles from an area of higher concentration to an area of lower concentration across a partially permiable membrane
• plasmolysis is the term used to describe the appearance of the plant cell when the plasma membrane pulls away from the cell wall.
• Crenation occurs when red blood cells shrink and develop a scalloped in a hypertonic solution.
• Active transport is the movement of particles from low to high concentration with the use of energy.
• Active transport works against a concentration gradient
• hypertonic animal cells become flacid
• hypotonic animal cells become turgid