biology-osmosis

what is diffusion

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

no energy is needed(passive)

what is active transport

opposite of diffusion( movement of particles from areas of low concentration to high concentration)

energy is needed

what is osmosis

• movement of water across semi-permeable cell membrane from areas of high water concentration to low concentration

• special type of diffusion

• passive

what is like a magnet to water

salt and sugar

what is isotonic

water and salt are equal

osmosis occurs but it is balanced

what happens to an animal cell in a concentrated salt solution

the cell loses water

shrivels up

some may die

what happens to an animal cell in distilled water

water moves in

swells

eventually bursts

what happens to a plant cell in a concentrated salt solution

cytoplasm shrivels

the cell becomes plasmolysed( cell membrane pulls away from the cell wall)

the empty space is filled with the salt soln

what happens to a plant cell in distilled water

water fills the cytoplasm and vacuole

membrane is pushed against the cell wall (turgor pressure)

cell becomes turgid

in an osmosis experiment what is used to resemble a semi permeable membrane

visking tubing

what are the common organisms that cause food spoilage

bacteria and fungi

describe how food is preserved in relation to osmosis

when food is placed in a sugar/salt soln. the bacteria and fungi present lose water through osmosis and shrivel up and die. food is then preserved

what are some examples of foods preserved by osmosis

bacon

tinned fruit