Plants and animals contain membrane-bound organelles called vacuoles. The lysosomes are specialised lysosomes in a way. It’s common to see vacuoles in plants and animals, and we have a few of them as well. A lysosome-like membrane-bound organelle is referred to as a vacuole in a more generic sense. Vacuoles are organelles found in many types of cells. A single membrane separates the fluid-filled, enclosed structures of the vacuoles from the cytoplasm. Fungi and plants have them most frequently. Nevertheless, some protists, animal cells, and bacteria may also contain vacuoles. In a cell, vacuoles play a number of important roles, including storage of nutrients, detoxification, and waste removal. 

Functions of Vacuole in Plant Cells

One membrane surrounds the vacuole of each plant cell. This membrane is called the tonoplast. In the body, vacuoles are formed when vesicles from the Golgi complex merge with vesicles from the endoplasmic reticulum. Newly emerging plant cells typically contain many smaller vacuoles. In the process of development, the fusion of smaller vacuoles forms a large central vacuole. Approximately 90% of the volume of each cell is taken up by the central vacuole.

• Vacuoles are used by plants differently from those by animals and other organisms. Many of the unique functions performed by vacuoles in plant cells allow plants to achieve important goals, such as growing upwards on strong stalks, assimilating sunlight for energy, and protecting themselves from predators and droughts.
• The vacuole in plant cells usually occupies a large portion of the cell compared to other organelles. Tonoplasts form a sac around a liquid called cell sap inside a plant cell vacuole. It contains water as well as other chemicals. 
• In addition, the sap from the cell can contain toxins that have been removed from the cell by the vacuole. Some plants use these toxins to defend themselves against herbivores.
• Water is moved in and out of the vacuole by osmosis when the ions in the cell sap are concentrated. Water moves into the vacuole if the concentration of ions within the tonoplast is higher. The cytoplasm outside of the vacuole has a higher ion concentration, so water flows out. With the movement of water into and out of the vacuole, the vacuole enlarges or contracts.
• When osmosis is used to manage the size of a vacuole, the internal pressure on the wall of the cell remains within a desirable range. It boosts the plant’s structure by stabilising and increasing turgor pressure. When a cell is growing, the turgor pressure of its vacuole can further play a role in stabilising it. Besides maintaining cell structure, the large vacuole also crowds other organelles into their ideal positions within the cell.

Function of Vacuole in Animal Cells

Animal cells don’t require a large central vacuole because they take up so much space inside the cell, unlike plant cells. This is especially true of animal cells, which lack cell walls to counter the turgor pressure within a large vacuole, which would cause animal cells to rupture. Based on the cell’s function and needs, an animal cell may have no vacuoles or numerous vacuoles.

• Rather than providing structural function, animal vacuoles are small and serve primarily as transport pathways for organic matter into and out of cells. The vacuoles participate in two types of transport: exocytosis and endocytosis.
• Exocytosis refers to the process of moving materials from a cell out through its vacuoles. A vacuole releases signals while it is exocytosis molecules so that other cells can retrieve them.
• Unlike exocytosis, endocytosis involves the entry of organic matter into animal cells through vacuoles. The vacuole of another cell can accept signalling molecules packaged and released by the vacuoles of other cells.
• Bacteria and other microbes can enter cells through vacuoles while maintaining cell integrity. Enzymes break down pathogens inside the vacuole.
• Similar to a vacuole, a tonoplast serves as a barrier to ensure that toxins and other toxins do not spread throughout the cell, thus protecting the animal from illness and danger.

Varieties of Vacuole

• Contractile Vacuole 

• A majority of them are found in freshwater algae and protist cells.
• An extensible and collapsible membrane encloses a contractile vacuole. The feeding canals draw water from the cytoplasm, which includes waste products. That water enters the contractile vacuoles.
• The process is called diastole, in which the vacuole swells up. Contractile vacuoles contact plasma membranes and collapse. They are thrown outside the vacuole.
• In addition to osmoregulation, contractile vacuoles also excrete waste.

• Food Vacuole

• Protozoan parasites of several lower animals and higher animals’ phagocytes contain them.
• Combining a phagosome and a lysosome produces a food vacuole. Food is digested by digestive enzymes that are present in the food vacuole.

• Sap Vacuole

• For the passage of different substances, it is equipped with a number of transport systems. Young plant cells and animal cells contain numerous sap vacuoles. 
• The cytoplasm is distributed in a thin layer around the large central vacuole.
• The purpose of this device is to permit rapid exchange of cytoplasm with the surrounding environment. 

• Air Vacuole

• Prokaryotes are the only organisms reported to contain them.
• Vacuoles do not form a single entity, nor does a common membrane surround them.
• Furthermore, air vacuoles are buoyant, mechanically strong, and provide protection against radiation.

Conclusion

Variable cell types and stages of plant development produce different types of vacuoles with complex morphology. Conditions such as hydration and nutrition influence the morphology of intestinal vacuoles. In the body, vacuoles are large and play a key role not only in structural support, but also in many other functions such as storage, waste disposal, protection, and growth. Vacuoles allow cells to perform their usual functions, so without vacuoles, they would eventually die.