Varieties of lysosome, structure and function of organelles

In the work proposed to you, we will consider in detail the organelles of a cell called lysosomes. Structure and functions are our main questions. We will also pay attention to the general structure of the cell. From this article you can find out what diseases are possible if the functioning of this organelle is disturbed.

As it became clear, lysosomes are an integral part of cells. But apart from them, other organoids are also distinguished. Imagine how small their size, because even the cage can not be seen with the naked eye. To study its structure use a special device called a microscope. You will learn about this right now.

Cell and its organelles

Although we consider in this article which lysosome structure and functions, it is very important to know other elements of the cell. To begin with, this is an elementary structural unit. From the location of the cell, its functions and composition depend.

All organelles can be divided into three groups:

• Two-membrane;
• Single-membrane;
• Non-membrane.

The first group includes plastids, nucleus and mitochondria. To the second - EPS, lysosomes, apparatus Golgi, vacuoles. To the third - ribosomes and cell center.

All cell organelles are needed for the proper functioning of the entire system. The structure of the organelle depends on its function.

Lysosomes

The structure and functions of this organelle will be considered a little later, and now we will talk a little about varieties and purposes.

These are quite strong elements of the cell. Above, they are covered with a single membrane, inside which there are various enzymes (there are about 60 of them all). We propose to read a short list:

• Proteases;
• Nucleases;
• Lipases;
• Phosphatase and so on.

All lysosomes can be roughly divided into two classes:

• Primary;
• Secondary.

In this case, the primary can move into the next stage. We will look at this process a little later. We now give one more classification of lysosomes:

• Fagolysosome;
• Autophagosome;
• Multivesicular corpuscles;
• Residual bodies.

Structure

The lysosomes whose structure and functions we consider in this review have very small dimensions (0.2 μm). Thanks to this in the cell, they can be quite a lot. In the last paragraph we gave a classification, now we will analyze how they are formed.

It is important to know that primary lysosomes are just formed organelles that are not capable of performing their direct function (digestion of substances by hydrolysis). Only by capturing cells that are unnecessary for the cell, they go to the secondary group and begin to digest the substances that have entered into them. The heterophagic vacuole is formed by the fusion of a phagosome and a primary vacuole. The autophagosome is an organelle formed by the fusion of the primary and vacuole-formed lysosome.

Functions

We briefly examined the features of the structure of the lysosome, now we can proceed to the functions performed by this organelle. So, we can distinguish the following:

• Intracellular digestion;
• Autolysis;
• Autophagy.

Now we suggest that you consider each of them separately. We pass to the next question.

Digestion

Some features of the structure of the lysosome allow the organelle to produce intracellular digestion. Since a cell can exist not only as a complex organism, it must fulfill all vital functions. In this process, primary lysosomes are involved together with digestive vacuoles.

We have already mentioned that there is a very large number of enzymes in the lysosome. If any compounds enter it, the latter decompose to the smallest particles that penetrate the membrane. Further, these compounds participate in other equally important processes.

Autolysis

We have already said that digestive processes occur in lysosomes. It is also important to know that lysosomes can kill the whole cell.

The thin membrane of these organelles can collapse, and the enzymes will be released. If this happens to all the lysosomes of the cell, it will die. The process is autolysis. We can cite the most common example of a tadpole. The disappearance of the tail of the future frog is a clear example of autolysis. Where do the useful substances go after the destruction of the cell? They do not disappear without a trace, but are absorbed by "neighbors".

Autophagy

Also, lysosomes perform a function called "autophagy." Everything sooner or later becomes old, ceases to fulfill its functions. If you look at the cell, some obsolete organoids can be replaced. How does this happen? The spent organoids are captured by lysosomes and cleaved to low molecular weight compounds under the action of enzymes. And in their place come new. All the particles that remained after the process of autophagy are needed for the cell to reproduce new cellular structures.

Here we also say that there are two types of autophagy: micro- and macroautophagy. Often, this process is observed in a state of stress (for example, severe fasting or excessive physical exertion).

Diseases

We examined the formation of lysosomes, their functions and structure, but sometimes it happens that failures occur in their work. Then a person falls ill. We suggest considering such a disease as Gaucher syndrome. In addition to this disease, there are about 50 other diseases associated with disrupting the work of lysosomes.

So, Gaucher's disease was first described in 1882 by Philip Gaucher, after whom this syndrome was named. This is the most common disease with impaired function of these organelles. It is the lack of an enzyme glucocerebrosidase. All this can have a bad effect on some organs, such as:

• spleen;
• liver;
• Kidney;
• lungs;
• brain.

Despite the seriousness of the problem, Gaucher syndrome can be cured. Now prescribe a lot of different drugs that support a person's life.