Water Potential and Osmosis

Flashcards covering key vocabulary and concepts related to water potential, solvation, and osmosis, including their effects on plant and animal cells.

Solvation

The interaction of a solvent (often water) with the dissolved solute/works well with polar solutes

Solvent Polarity

The most important factor in determining how well a solvent solvates a particular solute.

Polar Molecule

Water is a good solvent because it is a polar molecule, and it will therefore dissolve polar solutes easily.

Osmotically Active

Solutes such as sodium, potassium and chloride ions and glucose are said to be osmotically active because they dissolve in water and change the concentration of the solution.

Osmosis

The net movement of water from an area with a lower solute concentration to an area with a higher solute concentration across a semi-permeable membrane.

Isotonic Solution

There is no net movement of water between two isotonic solutions because there is no difference in concentration

Hypotonic Solution

A solution with a lower solute concentration compared to another solution.

Hypertonic Solution

A solution with a higher solute concentration compared to another solution.

Plasmolysis

When water leaves a plant cell in a hypertonic solution, the cell membrane pulls away from the cell wall, reduces the volume of the cytoplasm.

Turgor Pressure

The pressure exerted by the cell contents against the cell wall in a plant cell.

Crenation

Shrinkage of cells due to water loss in a hypertonic environment.

Lysed cell

A cell that has burst due to excessive water intake in a hypotonic solution, causing the cell membrane to rupture

solute

A substance dissolved in a solvent to form a solution, affecting osmotic balance

is water a good solvent and why?

Yes, because of its polarity, allowing it to dissolve many ionic and polar substances (eg. NaCl)

movement of water molecules due to osmosis depends on…

concentration of solute in the solution (form hypo to hyper)

what happens when an animal cell is put in a hypotonic solution?

water enters the cell by osmosis making it swell, and because it lacks the support of a cell wall the it eventually bursts

what happens when a plant cell is bathed in a hypertonic solution…

water exits the cell by osmosis, causing it to shrink and become plasmolyzed as the cell membrane pulls away from the cell wall (shriveled)

medical applications of isotonic solutions

intravenous drips, contact lens solutions, eye drops, rinsing wounds, frozen to slush for packing donor organs