Cellular Movement Passive and Active Transport
Passive Transport • Does NOT require ENERGY to move particles into or out of a cell • Movement of particles from HIGHER concentration to LOWER concentration • DIFFUSION – movement of particles • OSMOSIS – movement of water
DIFFUSION • Movement of particles from a HIGHER concentration to a LOWER concentration • Example: Smell of baking cookies from the oven moving through the house.
OSMOSIS • Movement of WATER from a HIGHER concentration to a LOWER concentration • Example: Plant taking in water during a rainy day.
Active Transport • Requires ATP ENERGY to move particles into or out of cell • Movement of particles from LOWER concentration to HIGHER concentration • Endocytosis • Exocytosis
ENDOCYTOSIS • Cell membrane encloses a vesicle filled with particles and absorbs it, BRINGING IT INTO the cell
EXOCYTOSIS • Cell membrane encloses a vesicle filled with particles and PUSHES IT OUT of the cell
Active Transport Example: • A person trying to squeeze into an already crowded elevator! • It takes ENERGY to do so!
Equilibrium • In all cases, cells want EQUILIBRIUM! Too much (or too little) of a good thing is BAD for the cell!
What happens to cells when put in salt water? • This is why you do not want to drink salt water when you are lost at sea!
Water moves out of the cell to try to reach equilibrium. The cell dries out!