ch13- diffusion and osmosis

a selectively permeable membrane

allows some but not all molecules to pass through

diffusion

the spreading out of molecules

from a region of high concentration to a region of low concentration

does diffusion require energy?

no- passive

osmosis

the movement of water molecules across a semi-permeable membrane

from a region of low solute concentration to a region of high solute concentration

solvent

a liquid that disolves other substances

eg, water

solute

a substance that has been disolved

eg, salt disolved in water

solution

the mixture of a solute and solvent

eg, salt water

what function does the kidneys have in osmosis?

they control the concentration of plasma

what will happen to an animal cell in a less concentrated solution?

it may burst and die

what adaptation have ameba that live in freshwater developed?

a contractile vacuole

What will happen to an animal cell in a more concentrated solution?

Shrivel and die

what is the force exerted by the cytoplasm and vacuole against the cell wall?

turgor (preesure)

plant cell in less cancentrated solution

turgid

plant cells in a more concentraded solution

plasmolysis, the vacuole and cytoplasm shrivel and the cell membrane moves away from the cell wall

Name an example of osmosis in food preservation

salting fidh or meat

What is used to demonstrate osmosis?

visking tubing, beaker, glass rod, sucrose solution, water