Today we will talk about what a vacuole is. This is another component of the cell, that is, an organoid. An organoid, or organelle, is the particles that make up cells, the latter, in turn, are the basis of everything that surrounds us.
In fact, the world is not what it seems at first glance. It is worth picking up a microscope, and our worldview will change dramatically. The first acquaintance with this device occurs in high school. Teachers should definitely give a lecture on the rules for using a microscope in order to avoid unpleasant incidents in such an exciting lesson. After a short digression, we will tell you about what a vacuole is. This is our main question.
Vacuole
Let's start the section with a definition. A vacuole is an organoid (single-membrane). It can be found in eukaryotic cells. Let's immediately introduce a small explanation: eukaryotes are cells containing a nucleus. The latter is separated from the cytoplasm by a double membrane. The value of the nucleus is great, it is in it that the DNA of the molecule is contained.
So, a vacuole is an organoid capable of performing many different functions (we will say a little about themlater). How are these organelles formed? They originate from provacuoles, and they appear before us in the form of membrane vesicles.
It is also important to know that all vacuoles can be divided into two groups:
- digestive;
- pulsing.
Sometimes pulsating vacuoles are called contractile. They help to remove decay products. What other functions does such a vacuole have, we will consider a little later.
In plant cells, vacuoles occupy more than half of the volume, sometimes they merge into one large organelle, which greatly exceeds the size of ordinary ones.
All vacuoles are limited by a membrane, it is called the tonoplast. Inside we can find cell sap. The latter consists of the following components:
- water;
- monosaccharides;
- disaccharides;
- tannins;
- carbs;
- nitrates;
- phosphates;
- chlorides;
- organic acids and other substances.
Functions
Now we propose to highlight the main functions of the organelles we are considering. The vacuole, the functions of which we will now list, can occupy the space of the cell from 5 to 90 percent. Its purpose directly depends on where this organelle is located.
As for the types of cells, there are much more of them in plants, and animals have temporary organelles. We have already said that, depending on the location, the vacuole can perform various functions. But we will highlight two main ones:
- relationship of organelles;
- transport function.
Plant cell
Now let's move on to a more detailed study of organelles in a plant cell. The cell vacuole is its main component. Let's list why:
- vacuole absorbs water;
- removes harmful substances;
- in some cases, vacuoles produce milky juice;
- participate in the process of splitting old organelles;
- store nutrients.
As you can see, the role of these organelles is really great. We mentioned that they are able to break down old organelles, that is, they perform the function of lysosomes. This means that vacuoles may have the enzymes necessary for the hydrolysis of the following substances:
- proteins;
- fat;
- carbs;
- nucleic acids;
- phytohormones;
- phytoncides and so on.
They are also involved in the process of photosynthesis, which is extremely important not only for plants, but also for other organisms.
Animal cage
Vacuoles can be found at:
- freshwater protozoa;
- multicellular invertebrates.
In the first case, we will meet contractile vacuoles that serve as a regulator. That is, they are able to absorb or release excess water. To the second group, we can include many organisms, among which:
- sponges;
- coelenterates;
- eyeworms;
- shellfish.
In these organisms, digestive vacuoles are formed,capable of intracellular digestion. The latter can also be formed in higher animals, but only in certain cells (phagocytes).
