Cell Boundaries Chapter 7-3
Cell Membrane Regulates what enters and leaves the cell
Diffusion Movement of molecules from high to low concentrations
Osmosis Movement of H 2 O from area of HIGH concentration to LOW across a selectively permeable membrane
Hypotonic (“below strength”) Water will move INTO the cell causing it to swell Cells could rupture if cell takes too much water in Increases turgor pressure “Hypo Hippo”
Hypertonic Solution “above strength” Dissolved substances are HIGHER OUTSIDE & LOWER INSIDE the cell H 2 O rushes out of the cell causing it to shrivel
Isotonic Solution “same strength” Dissolved substances are the SAME OUTSIDE and are the SAME INSIDE Movement inside the cell = movement outside
PRACTICE TIME
Facilitated Diffusion Molecules like glucose can’t just “diffuse”, they need help by a protein channel. DOES NOT REQUIRE ENERGY HIGH to LOW
Facilitated Diffusion High to Low
Active Transport Requires ENERGY!!! (ATP) adenosine tri- phosphate and protein pumps Low concentration to High concentration
Active Transport
“Going Against the Gradient”
Phagocytosis “Cell Eating”
Pinocytosis “cell drinking”
Exocytosis
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