One of the permanent structures of plant and animal cells are vacuoles. However, the difference in their structure and functions in these groups of living organisms is quite significant. What is a vacuole, the structure and functions of this structure will be discussed in detail in the article.
What is a vacuole?
The vacuole, the structural features and functions of which can vary considerably, always develops from the membrane vesicles of the endoplasmic reticulum and the Golgi complex. All vacuoles are single-membrane organelles. They are found only in the cells of eukaryotic organisms.
Vacuole: structure and functions (table)
Despite the common origin, these structures acquire a certain specialization in the process of ontogenesis. Where the vacuole can be located, the structure and functions of the organelle depending on the location - all these data are contained in the table.
| View of vacuole | Location features | Functions |
| Reserve | Located in plant cells, occupies most of the internal content | Storage of water with minerals dissolved in it |
| Digestive | Characteristic for cells of unicellular and multicellular animals | Implementation of the process of digestion, breakdown of organic substances |
| Contractile | Animal cells | Regulation of cell osmotic pressure |
Plant vacuoles
The vacuole, the structure and functions of which we are now considering, is characterized by very large sizes. Located in plant cells, it fills almost the entire space of the cytoplasm, from which it is separated by its own membrane - the tonoplast. This type of vacuole is a cavity filled with cell sap. It is a liquid based on water. Minerals, polysaccharides, protein monomers, some pigments are dissolved in it. This is a kind of reservoir in which all the necessary substances are stored. They help cells successfully survive all adverse periods. In some vacuoles, secondary metabolic products accumulate, for example, alkaloids, tannins, milky juice. They perform not only a storage, but also a protective function, scaring away many animals with an unpleasant astringent taste.
Contractile vacuoles
In the cells of unicellular animals there is a contractile vacuole. Its structure and functions are somewhat different. This is a pulsating vial that controls the levelintracellular pressure and concentration of substances. For example, amoeba and ciliates live in an aquatic environment, the concentration of s alts in which is usually higher than in their cytoplasm. According to the laws of physics, water will flow into the animal cell - from an area with a higher concentration to a lower one. As a result of such a process, the death of organisms would inevitably occur. Contractile vacuoles remove excess water with s alts dissolved in it, maintaining cell turgor at a constant level, being the "organ" of excretion.
Digestive vacuoles
These vacuoles are characteristic of animal organisms. In unicellular organisms, they look like vesicles into which nutrients enter and are digested. Excretion of metabolic products occurs anywhere in the cell membrane or through a specialized hole - powder. In multicellular organisms, lysosomes are a special form of vacuoles. These are single-membrane organelles containing hydrolytic enzymes. Lysosomes carry out the processes of pino- and phagocytosis, digesting not only nutrients, but also dead cell elements.
So, the vacuole, the structure and functions of which we have examined, is located in the cells of plant and animal organisms. Depending on its location, it can perform storage, digestive and regulatory functions.
