CELL TRANSPORT Cell membrane is semipermeable allows certain

CELL TRANSPORT • Cell membrane is semipermeable- allows certain things in, keeps certain things out • Some molecules can pass right through small spaces in membrane= DIFFUSIONhigh concentration to low concentration • Achieves equilibrium

OSMOSIS • Diffusion of water across membrane= osmosis • Cells must maintain certain concentration of water- water in cell creates osmotic pressure • Concentration of molecules (salts, sugars, ions) outside of cell usually = to inside • Thus- water moves in at the same rate it moves out

Osmotic Environments • Isotonic • Hypertonic

OSMOSIS • Isotonic- ISO- same • Concentration of solutes is = in and out of cell • Cell maintains regular shape

OSMOSIS • If concentration of solutes in the cell is greater than outside, then the outside is HYPOTONIC to the cell • Cell will swell as water rushes in • Think 1. ) Hypo- under, or low (solution has lower amount of particles) • 2. ) Hyp Otonic • Good for plant cells- creates turgor pressure

OSMOSIS • If concentration of solutes in the cell is less than outside, then the outside solution is HYPERTONIC to the cell • Cell will shrink because water rushes out • Think- HYPER= greater (solution has greater amount of particles) • Bad for plant cells- cells become PLASMOLYZED

OSMOSIS • Water always travels from the hypotonic area to the hypertonic area • Hypo------- Hyper H 2 O