Do you know what structure a cell of protozoa has? If not, then this article is for you.
What science studies the cell?
This science is called cytology. It is a branch of biology. She can answer the question of what structure the cell of the simplest has. Also, this science studies not only the structure, but also the processes that occur in the cell. These are cellular respiration, metabolism, reproduction and photosynthesis. The method of reproduction of protozoa is simple cell division. Some protozoan cells are capable of photosynthesis - the production of organic substances from inorganic ones. Cellular respiration occurs when glucose is broken down. This is the main function of simple carbohydrates in the cell. When they are oxidized, the cell receives energy.
Who are the protozoa?
Before considering the question of what structure a cell of protozoa has, let's figure out what these "creatures" are.
These are organisms that consist of one cell. They are also called eukaryotes because they have a nucleus in their cells. The protozoan cell is in many ways similar tocell of a multicellular organism.
Classification
There are six types of protozoa:
- ciliates;
- radiolarians;
- sunflowers;
- sporozoans;
- sarcoflagellates;
- flagellate.
Representatives of the first type inhabit s alt water bodies. Some species can also live in soil.
Sporozoans are mainly parasites of vertebrates.
Radiolarians, like ciliates, live in the oceans. They have hard shells of silicon dioxide, from which some rocks are formed.
The peculiarity of sunflowers is that they move with the help of pseudopodia.
The sarcoflagellates also use this method of locomotion. This type includes amoeba and many other protozoa.
Flagellates are represented by a wide variety of organisms that use flagella for movement. Some species of such protozoa can live in water bodies, and some are parasites. In addition, many representatives of this type have chloroplasts in their cells. Such protozoa themselves produce the nutrients necessary for life through photosynthesis.
What is the structure of a protozoan cell?
The structure of a cell can be divided into three main parts: the plasma membrane, the cytoplasm and the nucleus. The number of nuclei in the cells of the simplest is one. In this they differ from bacterial cells, which do not have nuclei at all. So, let's take a closer look at each of the three components.cells.
Plasma membrane
The structure of the protozoan cell necessarily provides for the presence of this component. It is responsible for maintaining cell homeostasis, protecting it from environmental influences. The plasma membrane is made up of three classes of lipids: phospholipids, glycolipids, and cholesterol. Phospholipids predominate in the structure of the membrane.
Cytoplasm: how is it arranged?
This is the entire part of the cell, with the exception of the nucleus, which is located inside the plasma membrane. It consists of hyaloplasm and organelles, as well as inclusions. Hyaloplasm is the internal environment of the cell. Organelles are permanent structures that perform certain functions, while inclusions are non-permanent structures that perform mainly a storage function.
Structure of the cell of protozoa: organelles
In the cell of the simplest there are many organelles that are characteristic of animal cells. In addition, unlike the cells of multicellular organisms, most protozoan cells have organelles of movement - all kinds of flagella, cilia and other structures. Very few cells of multicellular animals can boast of the presence of such formations - only spermatozoa.
The organelles that are present in protozoan cells include mitochondria, ribosomes, lysosomes, the endoplasmic reticulum, and the Golgi complex. In the cells of some protozoathere are also chloroplasts, which are characteristic of plant cells. Consider the structure and functions of each of them in the table.
| Organoid | Building | Functions |
| Mitochondria | They have two membranes: outer and inner, between which there is an intermembrane space. The inner membrane has outgrowths - cristae or ridges. All major chemical reactions take place on them. What is inside both membranes is called the matrix. In it, these organelles have their own ribosomes, inclusions, mitochondrial RNA and mitochondrial DNA. | Power generation. In these organelles, the process of cellular respiration takes place. |
| Ribosome | Consist of two subunits. They do not have membranes. One of the subunits is larger than the other. Ribosomes unite only in the process of functioning. When the organoid is not functioning, the two subunits are separated. | Protein synthesis (translation process). |
| Lysosomes | They have a rounded shape. They have one membrane. Inside the membrane are enzymes that are necessary for the breakdown of complex organic substances. | Cellular digestion. |
| Endoplasmic reticulum | Tubular shape. | Participates in metabolism, is responsible for lipid synthesis. |
| Golgi complex | Stack of disc-shaped tanks. | Serves for the synthesis of glycosaminoglycans, glycolipids. Modifies andclassifies proteins. |
| Chloroplasts | Possess two membranes with an intermembrane space between them. The matrix contains thylakoids united in stacks (grana by lamellae. In addition, the matrix contains ribosomes, inclusions, RNA and DNA. | Photosynthesis (occurs in thylakoids). |
| Vacuoles | Many freshwater protozoa have contractile vacuoles (spherical organelles with a single membrane) | Pumping out excess fluid from the body. |
In addition, protozoan cells are equipped with organelles of movement. It can be flagella and cilia. Depending on the species, an organism may have one or more flagella.
