BIOS 170

Lab 5


Diffusion Across Cell Membranes
Osmosis and Dialysis








MOVEMENT OF MOLECULES THROUGH CELL  MEMBRANES
Allows cells to maintain homeostasis
Provides cells with materials for metabolism
Transports products of metabolism and waste
 
 

DIFFUSION
Movement of molecules from an area of high to low concentration achieve equilibrium.
 
 










Diffusion Animation (Java-enabled browers only)
 

ACTIVE TRANSPORT
Movement of molecules against a concentration gradient, requiring energy.
 

OSMOSIS
Diffusion of water molecules through a selectively permeable membrane.
 

SELECTIVELY PERMEABLE MEMBRANE
Allowing some materials to pass through more easily than others.
 

SOLVENT
Liquid substance, such as water, in which other materials may be dissolved.
 

SOLUTE
The dissolved substance in a solution.
 

SOLUTION
Solute plus solvent.

RED BLOOD CELLS IN:
Isotonic Solution
Hypertonic Solution
Hypotonic Solution



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