In the work proposed to you, we propose to consider the functions of lysosomes, their purpose. Among some of the destinations, we will highlight the more significant ones and write about them in more detail.
To begin with, everything is made up of cells. These structural units are so small that we can only see them in the laboratory with special equipment. Now we are talking about a microscope, for the first time they get acquainted with its device in high school. Teachers offer several laboratory works with the participation of this tool to study the structure of onion scales or tree leaves.
The lysosome is an integral part of cells. We will talk about it further. Before considering the functions of lysosomes, we will briefly talk about the structure and significance of this organoid.
Lysosomes
We have already indicated in the preface that these are the constituent parts of the cell, and in translation from Latin they have a fairly clear meaning - the dissolution of the body. Lysosomes, whose functions we will consider a little later, look like small organelles, they are surrounded by a membrane. The cavity of the lysosome is filled with hydrolytic enzymes.constantly maintained acidic environment. What else is characteristic of the organelle we are considering? It does not have a permanent form, they are always very diverse. Their sizes are very small, since one cell can contain several hundred lysosomes. Their diameter is approximately equal to 0.2 microns.
Destination
Before we consider the functions of lysosomes in the form of a list, we will slightly indicate the significance of this organelle in the cell. These points overlap a lot. It is important to mention that this organelle is absent in plant cells, but it is present in humans and fungi. They are formed in the Golgi complex. We have already said that their cavities contain a very large number of various enzymes, due to which digestion occurs in the cells. Since these organelles are absent in plants, vacuoles can perform some of their functions.
The enzymes contained in these vesicles can break down:
- proteins;
- fats;
- carbs;
- nucleic acids.
Another task of lysosomes is the splitting of both individual parts and the entire cell. A good example here is the transformation of a tadpole into a frog. The tail disappears precisely under the influence of the enzymes of this organelle.
Functions
In this section, we propose to list the functions of lysosomes. The following can be distinguished:
- implementation of digestion in cells;
- autophagy;
- autolysis;
- dissolve.
To make it clearer,Let us explain the meaning of the words "autophagy" and "autolysis". In the first case, the destruction of unnecessary cell structures is implied, and in the second, self-digestion of the cell (we already mentioned this earlier in the example with a tadpole and a frog). In the last paragraph, we meant the dissolution of external structures.
Cell Digestion
When we considered the functions of the lysosome in the cell, we mentioned the ability of this organelle to carry out the process of digestion in the cell. Before we begin to explain this function, we need to clarify that there are several types of lysosomes. Namely:
- primary;
- secondary.
Primary lysosomes are also called storage or storage granules. We are more interested in secondary organelles in this matter. Since they include here:
- digestive vacuole;
- autophagous vacuole;
- residual body.
In the digestive vacuole, digestion of incoming substances occurs through hydrolysis. Digestion occurs, as a rule, to low molecular weight substances that can pass through the lysosome membrane. These substances are needed for important purposes - the synthesis of other organelles or intracellular structures.
Autophagy
The considered functions of the lysosome in the cell contain an item called "autophagy". Let's take a brief look at what this means. We have already said that this term refers to the destruction of unnecessary parts of the cell. This function is performed by secondary lysosomes, which are called autophagic vacuoles. They havea definite and permanent oval shape, the body is rather large. It contains:
- fragments of mitochondria;
- cytoplasmic reticulum;
- ribosomes and so on.
That is, it contains the remains of a cell. They are degradable by enzymes. The resulting residues do not disappear without a trace, but are involved in other important processes.
These vacuoles can be found in very large numbers in a number of cases, including:
- starvation;
- intoxication;
- hypoxia;
- aging and so on.
Autolysis
So, we figured out what functions lysosomes perform. Now we propose to consider in more detail one more of them, namely, autolysis. Lysosome membranes can be destroyed, then the enzymes are released and cease to carry out their normal activities, since the cytoplasm has a neutral environment, and the enzymes in it are simply inactivated.
There are cases when there is such a destruction of all lysosomes, which leads to the death of the entire cell. Two groups of autolysis can be distinguished:
- pathological (the most striking and common example is tissue destruction after death);
- regular.
