Membrane Structure and Function

A set of vocabulary flashcards covering key concepts related to membrane structure and function.

Diffusion

The movement of matter from an area of higher concentration to an area of lower concentration that occurs spontaneously without energy input.

Concentration Gradient

A gradient established when there is an area of higher concentration compared to an area of lower concentration.

Osmosis

The diffusion of water or solvent molecules across a selectively permeable membrane.

Tonicity

The relative solute concentration across a membrane; determines the direction of water movement.

Hypertonic

A solution that has a higher solute concentration compared to another solution.

Hypotonic

A solution that has a lower solute concentration compared to another solution.

Isotonic

A solution that has the same solute concentration as another solution.

Passive Transport

The movement of substances across a cell membrane without the need for energy input; includes diffusion and osmosis.

Facilitated Diffusion

The process of passive transport of molecules across a membrane via a channel or carrier protein.

Active Transport

The movement of substances across a membrane against their concentration gradient, requiring energy (ATP).

Endocytosis

The process by which a cell takes in large particles or molecules by engulfing them.

Exocytosis

The process of transporting large materials out of the cell using vesicles.

Pinocytosis

A type of endocytosis where the cell takes in extracellular fluid and dissolved solutes.

Phagocytosis

A type of endocytosis in which a cell engulfs large particles or other cells.

Receptor-Mediated Endocytosis

A process where cells absorb metabolites, hormones, other proteins - and in some cases viruses - by the inward budding of the plasma membrane.

Glycoproteins

Proteins that have carbohydrate molecules attached, involved in cell recognition and signaling.

Cholesterol

A lipid that helps to stabilize cell membranes and modulate their fluidity.