7.4 Cellular Transport

7.4 Cellular Transport Passive Transport· movement of molecules across a cell membrane without energy from the cell· requires NO energy· 3 types: diffusion, facilitated diffusion, osmosis

Diffusion· passive transport (NO energy needed)· molecules or ions move down their concentration gradient

high concentration to low concentrationlike sliding down a slide

· molecules continue to move until they reach equilibrium

concentration is equal and molecules move in both directions equally· example

exchange of CO2 and O2 in the lungs

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THINK: food coloring in water, OR the smell of a fart in class

Diffusion

Facilitated Diffusion· passive transport (NO energy needed)

high concentration until low concentration· diffusion with a helper· diffusion of molecules across a membrane through carrier proteins

facilitate - "to help"carrier proteins "help" molecules cross the mem.

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1 MATA: Passive transport

A does not require energy

Bmoves molecules from high to low concentration

C occurs until equilibrium is reached

D includes diffusion and osmosis

7.4 Cellular Transport

2 Facilitated diffusion

A requires energy from the cell

Bmoves molecules from low to high concentration

Cuses a protein to move molecules across the membrane

D is a type of active transport

Solute/Solvent Review

dissolved in solvent

does the dissolving

solute+

solvent

?? ?

Osmosis· passive transport (NO energy needed)· diffusion of H2O· H2O moves from high concentration to low concentration through a semipermeable membrane· water diffuses from more water to less water

Osmotic Solutions

· hypertonic - solute high, water low (outside cell) water moves out of cellcell shrivels up (crenates)

· hypotonic - solute low, water high (outside cell)water moves into cellcell can explode (cytolysis)

· isotonic - "equal strength" water moves into and out of cell equally

Water must flow from the hypo...

low solutehigh water

high solutelow water

? ? ?Water must flow from the hypo...

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Water must flow from the hypo...

7.4 Cellular Transport

Osmosis ExampleWith your BioBuddy…What will happen to a

houseplant if you water it with salt water (a hypertonic solution)?

A B CHint: Draw a Picture

3 What type of solution is this?

A isotonic

B hypotonic

C hypertonic

90% water10% salt

70% water30% salt

4 What direction will the water flow?

A out of the cell

B into the cell

Cinto and out of the cell

50% water50% sugar

50% water50% sugar

5 Osmosis is the movement of ____ through a semipermeable membrane.

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Active Transport· requires chemical energy· molecules move up their concentration gradient

low concentration to high concentrationlike climbing up a slide or a salmon swimming up stream

· requires a transport protein· example

proton (hydrogen) pump

7.4 Cellular Transport

Endocytosis· active process (requires energy)· "endo" - inside; "cyto" - cell· bringing material into the cell

phagocytosis (cell eating) - cell mem. engulfs large particles

Exocytosis· active transport (requires energy)· "exo" - outside; "cyto" - cell· vesicles fuse with membrane to expel substances from cell· opposite of endocytosis

6 What type of transport is this?

A diffusion

Bfacilitated diffusion

C osmosis

Dactive transport

7 Active transport requires energy, moves molecules against their concentration gradient (low to high), and includes osmosis and pinocytosis.

True False