de Duve named lysosomes based on their biochemical properties (from the Greek lysis – digestive and soma – body).

In protists,[a] vacuoles have the additional function of storing food which has been absorbed by the organism and assisting in the digestive and waste management process for the cell.

[14] In animal cells, vacuoles perform mostly subordinate roles, assisting in larger processes of exocytosis and endocytosis.

These materials are absorbed into secretory granules within the Golgi apparatus before being transported to the cell membrane and secreted into the extracellular environment.

In this capacity, vacuoles are simply storage vesicles which allow for the containment, transport and disposal of selected proteins and lipids to the extracellular environment of the cell.

The invagination is pinched off, leaving the engulfed material in the membrane-enclosed vacuole and the cell membrane intact.

Pinocytosis ("cell drinking") is essentially the same process, the difference being that the substances ingested are in solution and not visible under the microscope.

A vacuole is surrounded by a membrane called the tonoplast (word origin: Gk tón(os) + -o-, meaning “stretching”, “tension”, “tone” + comb.

Aside from storage, the main role of the central vacuole is to maintain turgor pressure against the cell wall.

Proteins found in the tonoplast (aquaporins) control the flow of water into and out of the vacuole through active transport, pumping potassium (K+) ions into and out of the vacuolar interior.

Another function of a central vacuole is that it pushes all contents of the cell's cytoplasm against the cellular membrane, and thus keeps the chloroplasts closer to light.

In Paramecium, the food vacuoles can show variation in size and shape based on their contents, solute balance and timing of ingestion in the cellular pharynx.

[28] The vacuoles of Ophrydium versatile undergo discoidal vesicle membrane recycling to the cytostome, condensing in the process, then associate with rough endoplasmic reticulum, receive protein coating on their cytosolic or exterior face from fusion with cup-shaped coated vesicles and condense again while producing cup-shaped coated vesicles, possibly for the purpose of enzyme recycling, prior to cytoproct egestion of residues mediated by vacuole fusion.