Types of Cellular Transport high low Weeee!!! Passive Transport cell doesn’t use energy Diffusion Facilitated Diffusion Osmosis Active Transport cell does use energy Protein Pumps Endocytosis Exocytosis high low This is gonna be hard work!!

Passive Transport (HighLow) cell uses no energy molecules move randomly Molecules spread out from an area of high concentration to an area of low concentration. (HighLow)

Concentration Gradient Concentration Gradient - change in the concentration of a substance from one area to another.

Passive Transport: 1. Diffusion Simple Diffusion Animation Passive Transport: 1. Diffusion Diffusion: random movement of particles from an area of high concentration to an area of low concentration. (High to Low) Diffusion continues until all molecules are evenly spaced (equilibrium is reached)-Note: molecules will still move around but stay spread out. http://bio.winona.edu/berg/Free.htm

Diffusion Molecules/ particles in solution tend to slowly spread apart over time. This is diffusion.

Diffusion Movement of molecules from an area of high concentration to an area of lower concentration. Factors that affect the rate of diffusion: size of molecules, size of pores in membrane, temperature, pressure, and concentration.

Diffusion [High] [Low] concentrated, high energy molecules diffuse, low energy molecules

Diffusion will continue until equilibrium is reached Diffusion will continue until equilibrium is reached. This means there will be an equal distribution of molecules throughout the space. This is why food coloring moves throughout a beaker of water; why odors smell strong at first and then disappear over time. Equilibrium, a result of diffusion, shows the uniform distribution of molecules of different substances over time as indicated in the above diagram.

Which molecules will diffuse in each of the figures below? 1 2 3 4 5 6

ANSWERS 1 2 3 4 No Movement 5 6 No Movement

Passive Transport: 2. Facilitated Diffusion Glucose molecules Cellular Transport From a- High High Concentration Cell Membrane Low Concentration Protein channel Low Transport Protein Through a  Go to Section:

Osmosis: the passive transport or diffusion of water through a selectively permeable membrane as a result of a concentration gradient   The direction of water movement across the cell membrane depends on the relative concentrations of free water molecules in the cytoplasm and in the fluid outside the cell.

There are three possibilities for the direction of water movement: Water moves out: When water diffuses out of the cell the cell shrinks. A hypertonic solution where there is a higher concentration of particles in solution outside the cell causes the particle-free water to move outside the cell. Water moves in: When water moves into the cell, the cell swells. A hypotonic solution where there is a greater concentration of particles in solutions inside the cell causes the particle free water to push into the cell. No net water movement: Occurs when the fluid outside and inside the cell have equal concentrations of particles in solution. This type of solution is called isotonic