Cellular Transport: Active Transport, Endocytosis, and Exocytosis

Vocabulary terms and definitions covering passive transport, active transport, and vesicle-mediated bulk transport mechanisms like endocytosis, phagocytosis, pinocytosis, and exocytosis.

Active transport

A cellular transport process requiring cellular energy (ATP) that can move substances from high to low or low to high concentration without having to stop at equilibrium, typically used for large molecules, bulk molecules, or charged ions.

Passive transport

A form of transport where molecules always move from a higher concentrated side to a lower concentrated side until they reach equilibrium.

ATP

The cellular energy required by all types of active transport to move substances across the cell membrane.

Endocytosis

A type of active bulk transport in which the cell membrane creates a concave, cave-like semicircle around multiple molecules and pinches closed to bring them into the cell all at once.

Vesicle

A small membrane-bound structure formed from phospholipids that carries molecules into the cell during endocytosis, or ships proteins and lipids out from the Golgi.

Phospholipids

The specific component of the cell membrane used to form the inward cave and resulting vesicle during endocytosis.

Phagocytosis

A Greek-derived term meaning 'cell eating'; a form of endocytosis where the cell brings in a large solid molecule, such as a bacterium engulfing another smaller bacterium.

Food vacuoles

Cell parts or structures formed specifically as a result of phagocytosis when large solid materials are engulfed.

Pinocytosis

A category of endocytosis characterized by the cell bringing in a bulk volume of liquids all at once.

Exocytosis

A category of active transport that operates as the reverse of endocytosis to move substances out of the cell.

Sodium and potassium

Charged molecules (electrolytes) moved via active transport to establish large concentration differences across cell membranes, enabling electrical communication between the body and brain.