Topic 8

Osmosis

the net diffusion of water molecules across a selectively permeable membrane from an area of higher water concentration to an area of lower water concentration

Tonicity

the ability of a solution to cause a cell to gain or lose water

Hypertonic

a hypertonic solution has a higher concentration of solutes outside the cell than inside it

Isotonic

one with the same solute concentration as the inside of a cell, meaning there is no net movement of water across the cell membrane

Hypotonic 

a solution with a lower concentration of solutes compared to the inside of a cell

osmoregulation

the active process by which organisms regulate their internal water and solute concentrations to maintain homeostasis

Plasmolysis

the process where a plant cell loses water in a hypertonic solution, causing the plasma membrane to shrink and detach from the cell wall

Turgid 

a plant cell that is swollen and rigid, with the plasma membrane pressed firmly against the cell wall