movement of water across membrnes by osmosis and the effects that solutions of different water potential can have on plant and animall cells

osmosis

the net movement of water molecules from a more dilute solution to a more concentrates one

water potential

the pressure exerted by water molecules as they collide with a membrane or container

measure in KPa

all solutions have negative water potentials

water diffuses from high water potential to low water potential

pure water - water potential

0 KPa

the highest value

all solutions have negative water potentials

relations between inside and outside the membrane

isotonic

hypotonic

hypertonic

isotonic

hypotonic

hypertonic

isotonic - same conc. solution as cell cytoplasm

hypotonic- lower conc. solution than cell cytoplasm

hypertonic- higher conc. solution than cell cytoplasm

animal cell - diff solutions

hypertonic solution - water potential is lower outside the cell = water moves out of the cell = cell shrivels

→crenation

isotonic - water potential inside and outside of cell is equivalent = no net movement of water

→ equilibrium

hypotonic solution - water potential higher outside the cell = water moves into the cell

→ cell bursts

plant cell - diff solutions

hypertonic solution - water moves out of the cell = cell becomes plasmolysed - cell pulls away from cell wall

→flaccid

isotonic - no net movement of water

→ equilibrium

→ flaccid

hypotonic solution - water moves into the cell

→ turgid

how do you find the water potential inside the cell

where the line crosses the x-axis