Although Vacuoles are present in both animal and plant cells, they are particularly large and abundant in plant cells, often occupying a major portion of the cell volume and forcing the remaining intracellular structures into a thin peripheral layer.
Structure of Vacuoles:
These are bound by a single membrane and are formed by the coalescence of smaller vacuole during the plant’s growth and development. The membrane of vacuole is composed of phospholipids. In the membrane-embedded proteins are present which allow the transportation of molecules.
- Vacuoles of plant cells are larger than those found in animal cells. The central vacuole present in plant cells is one of the important cell organelles.
- The central vacuole, surrounded by tonoplast, offers support to cells which constitute leaves and other soft parts of plants.
- The solutes present in vacuoles are known to absorb water.
- When water enters the vacuoles, cells become inflated; it allows the soft parts of plants (for example, leaves) to retain their shape and turgidity.
- In short, vacuole help in maintaining the cell in a proper shape.
- In animal’s cells, vacuoles play a subordinate role in the processes of endocytosis and exocytosis.
- In exocytosis, proteins and lipids are expelled from cells which is the major function of the vacuole.
- They don’t play a direct role in the extrusion of lipids and proteins.
- However, they act as containers of lipids and proteins.
- They also perform exocytosis. It is the reverse of exocytosis.
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