Vacuoles are large cavities or sacs found in plant cells, protozoans, and various other organisms. In plant cells, vacuoles are particularly prominent and often occupy a large portion of the cell volume. They are membrane-bound compartments that are involved in a range of cellular functions, including storage, waste disposal, and maintaining the cell's shape and turgor. For example, plant cells store various substances such as water, mineral salts, pigments, and sugars within their vacuoles. Protozoans and some other microorganisms also have vacuoles that play a role in nutrient storage, digestion, and osmoregulation.