Crossing the Membrane,
Facilitated Diffusion and Active Transport
Day 3
Facilitated Diffusion – Transport of substances from high concentration to low with aid of proteins
Remember, diffusion is ALWAYS high to low.
Molecules are ‘allowed’ to pass through membrane with help of Carrier Proteins
No energy needed
Facilitated Diffusion
http://www.youtube.com/watch?v=s0p1ztrbXPY
Active Transport – Movement of substances across a cell membrane from an area of low to high concentration WITH the use of energy.
Against the Concentration Gradient
Low -> High concentration
Endocytosis - Exocytosis
Active Transport
Endocytosis – when the cell membrane surrounds a particle, encloses it, and brings it into the cell.
Endo – take in
White blood cells use this process to exterminate threats in our body
Two Types:
Exocytosis – The cell releases a substance within it through its membrane.
Exo - release
Two Types:
Low to high concentration, in one of two ways:
Higher outside<-Exocytosis
Higher inside Endocytosis
http://www.youtube.com/watch?v=1w10R9lv7eQ
Endocytosis / Exocytosis Animation
Slug http://www.youtube.com/watch?v=PiQkebrC
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