Vacuol: structure and functions of organelles in plant and animal cells

One of the permanent structures of cells of plants and animals are vacuoles. However, the difference in their structure and functions in these groups of living organisms is quite significant. What is the vacuole, the structure and functions of this structure will be discussed in detail in the article.

What is the vacuole?

Vacuol, the features of the structure and functions of which can vary in significant limits, always develops from the membrane vesicles of the endoplasmic reticulum and the Golgi complex. All vacuoles are single-membrane organelles. They are located only in cells of eukaryotic organisms.

Vacuol: structure and functions (table)

Despite the common origin, these structures in the process of ontogenesis acquire a certain specialization. Where the vacuole, structure and functions of the organelle can be located, depending on the location - all these data are contained in the table.

Plant Vacuoles

Vacuol, whose structure and functions we are now considering, is characterized by very large dimensions. Located in plant cells, it fills almost the whole cytoplasm space, from which it is separated by its own shell - tonoplast. This type of vacuole is a cavity filled with cell sap. It is a liquid based on water. In it, minerals, polysaccharides, protein monomers, and some pigments are dissolved. It is a kind of reservoir in which all the necessary substances are stored. They help the cells successfully survive all the unfavorable periods. In some vacuoles secondary products of metabolism, for example, alkaloids, tannins, milky juice accumulate. They perform not only a reserve, 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. It is a pulsating vesicle that controls the level of intracellular pressure and concentration of substances. For example, amoeba and infusoria live in an aquatic environment, the concentration of salts in which is usually higher than in their cytoplasm. According to the laws of physics, water will enter the animal cage - from an area with a higher concentration to a smaller one. As a result of such a process, the death of organisms would inevitably occur. The contractile vacuoles deduce an excess of water with salts dissolved in it, maintaining the turgor of the cell at a constant level, being the "organ" of excretion.

Digestive vacuoles

These vacuoles are characteristic of animal organisms. In unicellular cells, they look like bubbles into which nutrients enter and are digested. Derivation of metabolic products occurs anywhere in the cell membrane or through a specialized hole - powder. In multicellular organisms, the special form of vacuoles is lysosomes. These are single-membrane organelles containing hydrolytic enzymes. Lysosomes carry out the processes of pinot and phagocytosis, digesting not only nutrients, but also dead cells.

So, the vacuole, the structure and functions of which we have considered, is found in the cells of plant and animal organisms. Depending on the location, it can perform storage, digestive and regulatory functions.