Diffusion and Osmosis

Vocabulary practice flashcards covering membrane permeability, diffusion, osmosis, turgor pressure, plasmolysis, and active transport.

Impermeable membrane

A membrane that will not allow any substances to pass through it.

Permeable membrane

A membrane that allows substances to pass freely through it.

Selectively permeable membrane

A membrane (also called semi-permeable) that allows some substances to pass through it while blocking others.

Diffusion

The passive movement of molecules from an area of high concentration to an area of low concentration without requiring additional energy.

Passive process

A transport process across or within cells that does not require any additional energy.

Osmosis

The movement of water from an area of high water concentration to an area of low water concentration across a semi-permeable membrane.

Isotonic solution

A solution whose solute concentration is equal to the solute concentration of the cell cytoplasm, resulting in no net movement of water.

Hypotonic solution

A solution whose solute concentration is lower than the solute concentration inside the cytoplasm of the cell, causing water to enter the cell.

Hypertonic solution

A solution whose solute concentration is greater than the solute concentration inside the cytoplasm of the cell, causing water to leave the cell.

Kidneys

Organs that preserve cellular integrity by maintaining a blood plasma concentration identical to that of blood cells.

Turgor pressure

The outward force exerted by cell contents against the cell wall in plant cells, giving structural strength to non-woody plants.

Turgid cell

A plant cell whose contents push firmly against the cell wall due to turgor pressure after water enters by osmosis in a hypotonic solution.

Plasmolysis

The loss of turgor pressure in a plant cell due to water leaving the cytoplasm, causing the cell membrane to shrink away from the cell wall.

Flaccid plant cell

The state of a plant cell placed in an isotonic solution, where water moves into and out of the cell at equal rates.

Food preservation by osmosis

A preservation method using concentrated sugar or salt solutions to draw water out of bacterial or fungal cells, stopping decay and toxin production.

Active transport

The movement of substances into a cell against their concentration gradient using membrane proteins and cellular energy.

Cellophane bag osmosis experiment

An experimental demonstration showing water uptake or loss in cellophane bags containing $2\%$ sugar solution when placed in hypotonic (distilled water), isotonic ($2\%$ sugar), or hypertonic ($10\%$ sugar) external solutions.

Red blood cell behavior in varied solutions

An illustration showing red blood cells shriveling in a hypertonic solution, maintaining volume in an isotonic solution, and swelling or bursting in a hypotonic solution.

Plant cell states in varied solutions

An illustration showing plant cells becoming plasmolyzed in a hypertonic solution, flaccid in an isotonic solution, and turgid in a hypotonic solution.