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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