Cell structure of various organisms. Cell structure and function

Objects of living nature have a cellular structure similar to all species. However, each kingdom has its own characteristics. This article will help you find out in more detail what the structure of an animal cell is, in which we will tell you not only about the features, but also introduce you to the functions of organelles.

A complex animal organism consists of a large number of tissues. The shape and purpose of the cell depends on the type of tissue it is part of. Despite their diversity, it is possible to identify common properties in the cellular structure:

• membrane consists of two layers that separate the contents from the external environment. Its structure is elastic, so cells can have a variety of shapes;
• cytoplasm located inside the cell membrane. It is a viscous liquid that is constantly moving;

Due to the movement of the cytoplasm, various chemical processes and metabolism occur inside the cell.

• core - has a large size compared to plants. Located in the center, inside it there is nuclear juice, a nucleolus and chromosomes;
• mitochondria consist of many folds - cristae;
• endoplasmic reticulum has many channels through which nutrients enter the Golgi apparatus;
• a complex of tubules called Golgi apparatus , accumulates nutrients;
• lysosomes regulate the amount of carbons and other nutrients;
• ribosomes located around the endoplasmic reticulum. Their presence makes the network rough; the smooth surface of the ER indicates the absence of ribosomes;
• centrioles - special microtubules that are absent in plants.

Rice. 1. The structure of an animal cell.

Scientists recently discovered the presence of centrioles. Because they can only be seen and studied using an electron microscope.

Functions of cell organelles

Each organelle performs certain functions, and their joint work constitutes a single, cohesive organism. For example:

• cell membrane ensures the transport of substances into and out of the cell;
• Inside the nucleus there is a genetic code that is passed on from generation to generation. Exactly core regulates the functioning of other cell organelles;
• The energy stations of the body are mitochondria . It is here that the substance ATP is formed, the breakdown of which releases a large amount of energy.

Rice. 2. The structure of mitochondria

• on the walls Golgi apparatus fats and carbohydrates are synthesized, which are necessary for building the membranes of other organelles;
• lysosomes break down unnecessary fats and carbohydrates, as well as harmful substances;
• ribosomes synthesize protein;
• cell center (centrioles) play an important role in the formation of the spindle during cell mitosis.

Rice. 3. Centrioles.

Unlike a plant cell, an animal cell does not have vacuoles. However, temporary small vacuoles may form that contain substances to be removed from the body.

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What have we learned?

The structure of an animal cell, which is studied in biology lessons in grades 7-9, is no different from the structure of other living cells. A feature of an animal cell is the presence of a cell center, the so-called centrioles, which participate in the formation of the division spindle during mitosis. Unlike a plant organism, there are no vacuoles, plastids, or cellulose cell walls. The cell membrane is quite elastic, which makes it possible for cells to acquire various shapes and sizes.

You have figured out for yourself what body type you are and how human muscles are structured. It's time to “Look into the muscle”...

First, remember (who forgot) or understand (who didn’t know) that there are three types of muscle tissue in our body: cardiac, smooth (muscles of internal organs) and skeletal.

It is the skeletal muscles that we will consider within the framework of the material on this site, because skeletal muscles form the image of an athlete.

Muscle tissue is a cellular structure and it is the cell, as a unit of muscle fiber, that we now have to consider.

First you need to understand the structure of any human cell:

As can be seen from the figure, any human cell has a very complex structure. Below I will give general definitions that will appear on the pages of this site. For a superficial examination of muscle tissue at the cellular level, they will be sufficient:

Core- the “heart” of the cell, which contains all hereditary information in the form of DNA molecules. The DNA molecule is a polymer shaped like a double helix. In turn, the helices are a set of four types of nucleotides (monomers). All proteins in our body are encoded by the sequence of these nucleotides.

Cytoplasm (sarcoplasm- in a muscle cell) - one might say, the environment in which the nucleus is located. Cytoplasm is the cellular fluid (cytosol) containing lysosomes, mitochondria, ribosomes and other organelles.

Mitochondria– organelles that provide cell energy processes, such as the oxidation of fatty acids and carbohydrates. During oxidation, energy is released. This energy is aimed at unification Adenesine diphosphate (ADP) And third phosphate group, as a result of which, is formed Adenesine triphosphate (ATP)– an intracellular source of energy that supports all processes occurring in the cell (more details). During the reverse reaction, ADP is formed again and energy is released.

Enzymes- specific substances of a protein nature that serve as catalysts (accelerators) of chemical reactions, thereby significantly increasing the speed of chemical processes in our bodies.

Lysosomes- a kind of round shell containing enzymes (about 50). The function of lysosomes is the breakdown, with the help of enzymes, of intracellular structures and everything that the cell absorbs from the outside.

Ribosomes- the most important cellular components that serve to form a protein molecule from amino acids. The formation of a protein is determined by the genetic information of the cell.

Cell membrane (membrane)– ensures cell integrity and is able to regulate intracellular balance. The membrane is able to control exchange with the environment, i.e. one of its functions is to block some substances and transport others. Thus, the state of the intracellular environment remains constant.

A muscle cell, like any cell in our body, also has all the components described above, however, it is extremely important that you understand the general structure of muscle fiber specifically, which is described in the article.

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All living beings and organisms do not consist of cells: plants, fungi, bacteria, animals, people. Despite its minimal size, all the functions of the whole organism are performed by the cell. Complex processes take place inside it, on which the vitality of the body and the functioning of its organs depend.

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Structural features

Scientists are studying structural features of the cell and the principles of its work. A detailed examination of the structural features of a cell is possible only with the help of a powerful microscope.

All our tissues - skin, bones, internal organs consist of cells that are construction material, come in different shapes and sizes, each variety performs a specific function, but the main features of their structure are similar.

First let's find out what's behind it structural organization of cells. In the course of their research, scientists have found that the cellular foundation is membrane principle. It turns out that all cells are formed from membranes, which consist of a double layer of phospholipids, where protein molecules are immersed on the outside and inside.

What property is characteristic of all types of cells: the same structure, as well as functionality - regulation of the metabolic process, use of their own genetic material (presence and RNA), receipt and consumption of energy.

The structural organization of the cell is based on the following elements that perform a specific function:

• membrane- cell membrane, consists of fats and proteins. Its main task is to separate substances inside from the external environment. The structure is semi-permeable: it can also transmit carbon monoxide;
• core– the central region and main component, separated from other elements by a membrane. It is inside the nucleus that there is information about growth and development, genetic material, presented in the form of DNA molecules that make up the composition;
• cytoplasm- this is a liquid substance that forms the internal environment where various vital processes take place and contains many important components.

What does the cellular content consist of, what are the functions of the cytoplasm and its main components:

1. Ribosome- the most important organelle that is necessary for the processes of biosynthesis of proteins from amino acids; proteins perform a huge number of vital tasks.
2. Mitochondria- another component located inside the cytoplasm. It can be described in one phrase - an energy source. Their function is to provide components with power for further energy production.
3. Golgi apparatus consists of 5 - 8 bags that are connected to each other. The main task of this apparatus is to transfer proteins to other parts of the cell to provide energy potential.
4. Damaged elements are cleaned lysosomes.
5. Handles transportation endoplasmic reticulum, through which proteins move molecules of useful substances.
6. Centrioles are responsible for reproduction.

Core

Since it is a cellular center, special attention should be paid to its structure and functions. This component is the most important element for all cells: it contains hereditary characteristics. Without the nucleus, the processes of reproduction and transmission of genetic information would become impossible. Look at the picture depicting the structure of the nucleus.

• The nuclear membrane, which is highlighted in lilac, lets the necessary substances in and releases them back through the pores - small holes.
• Plasma is a viscous substance and contains all other nuclear components.
• the core is located in the very center and has the shape of a sphere. Its main function is the formation of new ribosomes.
• If you examine the central part of the cell in cross-section, you can see subtle blue weaves - chromatin, the main substance, which consists of a complex of proteins and long strands of DNA that carry the necessary information.

Cell membrane

Let's take a closer look at the work, structure and functions of this component. Below is a table that clearly shows the importance of the outer shell.

Chloroplasts

This is another most important component. But why weren’t chloroplasts mentioned earlier, you ask? Yes, because this component is found only in plant cells. The main difference between animals and plants is the method of nutrition: in animals it is heterotrophic, and in plants it is autotrophic. This means that animals are not able to create, that is, synthesize organic substances from inorganic ones - they feed on ready-made organic substances. Plants, on the contrary, are capable of carrying out the process of photosynthesis and contain special components - chloroplasts. These are green plastids containing the substance chlorophyll. With its participation, light energy is converted into the energy of chemical bonds of organic substances.

Interesting! Chloroplasts are concentrated in large quantities mainly in the above-ground parts of plants - green fruits and leaves.

If you are asked the question: name an important feature of the structure of the organic compounds of a cell, then the answer can be given as follows.

• many of them contain carbon atoms, which have different chemical and physical properties, and are also capable of combining with each other;
• are carriers, active participants in various processes occurring in organisms, or are their products. This refers to hormones, various enzymes, vitamins;
• can form chains and rings, which provides a variety of connections;
• are destroyed when heated and interacting with oxygen;
• atoms within molecules are combined with each other using covalent bonds, do not decompose into ions and therefore interact slowly, reactions between substances take a very long time - several hours and even days.

Structure of chloroplast

Fabrics

Cells can exist one at a time, as in unicellular organisms, but most often they combine into groups of their own kind and form various tissue structures that make up the organism. There are several types of tissues in the human body:

• epithelial– concentrated on the surface of the skin, organs, elements of the digestive tract and respiratory system;
• muscular— we move thanks to the contraction of the muscles of our body, we carry out a variety of movements: from the simplest movement of the little finger to high-speed running. By the way, the heartbeat also occurs due to the contraction of muscle tissue;
• connective tissue makes up up to 80 percent of the mass of all organs and plays a protective and supporting role;
• nervous- forms nerve fibers. Thanks to it, various impulses pass through the body.

Reproduction process

Throughout the life of an organism, mitosis occurs - this is the name given to the process of division. consisting of four stages:

1. Prophase. The cell's two centrioles divide and move in opposite directions. At the same time, the chromosomes form pairs, and the nuclear shell begins to collapse.
2. The second stage is called metaphases. The chromosomes are located between the centrioles, and gradually the outer shell of the nucleus completely disappears.
3. Anaphase is the third stage, during which the centrioles continue to move in the opposite direction from each other, and individual chromosomes also follow the centrioles and move away from each other. The cytoplasm and the entire cell begin to shrink.
4. Telophase– final stage. The cytoplasm contracts until two identical new cells appear. A new membrane is formed around the chromosomes and one pair of centrioles appears in each new cell.

Interesting! Cells in epithelium divide faster than in bone tissue. It all depends on the density of the fabrics and other characteristics. The average lifespan of the main structural units is 10 days.

Cell structure. Cell structure and functions. Cell life.

Conclusion

You learned what the structure of a cell is - the most important component of the body. Billions of cells make up an amazingly wisely organized system that ensures the performance and vital activity of all representatives of the animal and plant world.

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The cells of animals and plants, both multicellular and unicellular, are in principle similar in structure. Differences in the details of cell structure are associated with their functional specialization.

The main elements of all cells are the nucleus and cytoplasm. The nucleus has a complex structure that changes at different phases of cell division, or cycle. The nucleus of a nondividing cell occupies approximately 10–20% of its total volume. It consists of karyoplasm (nucleoplasm), one or more nucleoli (nucleoli) and a nuclear membrane. Karyoplasm is a nuclear sap, or karyolymph, in which there are strands of chromatin that form chromosomes.

Basic properties of the cell:

• metabolism
• sensitivity
• reproductive capacity

The cell lives in the internal environment of the body - blood, lymph and tissue fluid. The main processes in the cell are oxidation and glycolysis - the breakdown of carbohydrates without oxygen. Cell permeability is selective. It is determined by the reaction to high or low salt concentrations, phago- and pinocytosis. Secretion is the formation and release by cells of mucus-like substances (mucin and mucoids), which protect against damage and participate in the formation of intercellular substance.

Types of cell movements:

1. amoeboid (pseudopods) – leukocytes and macrophages.
2. sliding – fibroblasts
3. flagellar type – spermatozoa (cilia and flagella)

Cell division:

1. indirect (mitosis, karyokinesis, meiosis)
2. direct (amitosis)

During mitosis, the nuclear substance is distributed evenly between daughter cells, because Nuclear chromatin is concentrated in chromosomes, which split into two chromatids that separate into daughter cells.

Structures of a living cell

Chromosomes

Mandatory elements of the nucleus are chromosomes, which have a specific chemical and morphological structure. They take an active part in the metabolism in the cell and are directly related to the hereditary transmission of properties from one generation to another. It should, however, be borne in mind that although heredity is ensured by the entire cell as a single system, nuclear structures, namely chromosomes, occupy a special place in this. Chromosomes, unlike cell organelles, are unique structures characterized by constant qualitative and quantitative composition. They cannot replace each other. An imbalance in the chromosomal complement of a cell ultimately leads to its death.

Cytoplasm

The cytoplasm of the cell exhibits a very complex structure. The introduction of thin sectioning techniques and electron microscopy made it possible to see the fine structure of the underlying cytoplasm. It has been established that the latter consists of parallel complex structures in the form of plates and tubules, on the surface of which there are tiny granules with a diameter of 100–120 Å. These formations are called the endoplasmic complex. This complex includes various differentiated organelles: mitochondria, ribosomes, Golgi apparatus, in the cells of lower animals and plants - centrosome, in animals - lysosomes, in plants - plastids. In addition, a number of inclusions that take part in the cell’s metabolism are found in the cytoplasm: starch, fat droplets, urea crystals, etc.

Membrane

The cell is surrounded by a plasma membrane (from the Latin “membrane” - skin, film). Its functions are very diverse, but the main one is protective: it protects the internal contents of the cell from the influences of the external environment. Thanks to various outgrowths and folds on the surface of the membrane, the cells are firmly connected to each other. The membrane is permeated with special proteins through which certain substances needed by the cell or to be removed from it can move. Thus, metabolism occurs through the membrane. Moreover, what is very important, substances are passed through the membrane selectively, due to which the required set of substances is maintained in the cell.

In plants, the plasma membrane is covered on the outside with a dense membrane consisting of cellulose (fiber). The shell performs protective and supporting functions. It serves as the outer frame of the cell, giving it a certain shape and size, preventing excessive swelling.

Core

Located in the center of the cell and separated by a two-layer membrane. It has a spherical or elongated shape. The shell - karyolemma - has pores necessary for the exchange of substances between the nucleus and the cytoplasm. The contents of the nucleus are liquid - karyoplasm, which contains dense bodies - nucleoli. They secrete granules - ribosomes. The bulk of the nucleus is nuclear proteins - nucleoproteins, in the nucleoli - ribonucleoproteins, and in the karyoplasm - deoxyribonucleoproteins. The cell is covered with a cell membrane, which consists of protein and lipid molecules that have a mosaic structure. The membrane ensures the exchange of substances between the cell and the intercellular fluid.

EPS

This is a system of tubules and cavities, on the walls of which there are ribosomes that provide protein synthesis. Ribosomes can be freely located in the cytoplasm. There are two types of EPS - rough and smooth: on the rough EPS (or granular) there are many ribosomes that carry out protein synthesis. Ribosomes give membranes their rough appearance. Smooth ER membranes do not carry ribosomes on their surface; they contain enzymes for the synthesis and breakdown of carbohydrates and lipids. Smooth EPS looks like a system of thin tubes and tanks.

Ribosomes

Small bodies with a diameter of 15–20 mm. They synthesize protein molecules and assemble them from amino acids.

Mitochondria

These are double-membrane organelles, the inner membrane of which has projections - cristae. The contents of the cavities are matrix. Mitochondria contain a large number of lipoproteins and enzymes. These are the energy stations of the cell.

Plastids (characteristic only of plant cells!)

Their content in the cell is the main feature of the plant organism. There are three main types of plastids: leucoplasts, chromoplasts and chloroplasts. They have different colors. Colorless leucoplasts are found in the cytoplasm of cells of uncolored parts of plants: stems, roots, tubers. For example, there are many of them in potato tubers, in which starch grains accumulate. Chromoplasts are found in the cytoplasm of flowers, fruits, stems, and leaves. Chromoplasts provide yellow, red, and orange colors to plants. Green chloroplasts are found in the cells of leaves, stems and other parts of the plant, as well as in a variety of algae. Chloroplasts are 4-6 microns in size and often have an oval shape. In higher plants, one cell contains several dozen chloroplasts.

Green chloroplasts are able to transform into chromoplasts - that’s why the leaves turn yellow in the fall, and green tomatoes turn red when ripe. Leucoplasts can transform into chloroplasts (greening of potato tubers in the light). Thus, chloroplasts, chromoplasts and leucoplasts are capable of mutual transition.

The main function of chloroplasts is photosynthesis, i.e. In chloroplasts, in the light, organic substances are synthesized from inorganic ones due to the conversion of solar energy into the energy of ATP molecules. The chloroplasts of higher plants are 5-10 microns in size and resemble a biconvex lens in shape. Each chloroplast is surrounded by a double membrane that is selectively permeable. The outside is a smooth membrane, and the inside has a folded structure. The main structural unit of the chloroplast is the thylakoid, a flat double-membrane sac that plays a leading role in the process of photosynthesis. The thylakoid membrane contains proteins similar to mitochondrial proteins that participate in the electron transport chain. The thylakoids are arranged in stacks resembling stacks of coins (10 to 150) called grana. Grana has a complex structure: chlorophyll is located in the center, surrounded by a layer of protein; then there is a layer of lipoids, again protein and chlorophyll.

Golgi complex

This is a system of cavities delimited from the cytoplasm by a membrane and can have different shapes. The accumulation of proteins, fats and carbohydrates in them. Carrying out the synthesis of fats and carbohydrates on membranes. Forms lysosomes.

The main structural element of the Golgi apparatus is the membrane, which forms packets of flattened cisterns, large and small vesicles. The cisterns of the Golgi apparatus are connected to the channels of the endoplasmic reticulum. Proteins, polysaccharides, and fats produced on the membranes of the endoplasmic reticulum are transferred to the Golgi apparatus, accumulate inside its structures and are “packaged” in the form of a substance, ready either for release or for use in the cell itself during its life. Lysosomes are formed in the Golgi apparatus. In addition, it is involved in the growth of the cytoplasmic membrane, for example during cell division.

Lysosomes

Bodies delimited from the cytoplasm by a single membrane. The enzymes they contain accelerate the breakdown of complex molecules into simple ones: proteins into amino acids, complex carbohydrates into simple ones, lipids into glycerol and fatty acids, and also destroy dead parts of the cell and entire cells. Lysosomes contain more than 30 types of enzymes (protein substances that increase the rate of chemical reactions tens and hundreds of thousands of times) capable of breaking down proteins, nucleic acids, polysaccharides, fats and other substances. The breakdown of substances with the help of enzymes is called lysis, hence the name of the organelle. Lysosomes are formed either from the structures of the Golgi complex or from the endoplasmic reticulum. One of the main functions of lysosomes is participation in the intracellular digestion of nutrients. In addition, lysosomes can destroy the structures of the cell itself when it dies, during embryonic development, and in a number of other cases.

Vacuoles

They are cavities in the cytoplasm filled with cell sap, a place of accumulation of reserve nutrients and harmful substances; they regulate the water content in the cell.

Cell center

It consists of two small bodies - centrioles and centrosphere - a compacted section of the cytoplasm. Plays an important role in cell division

Cell movement organelles

1. Flagella and cilia, which are cell outgrowths and have the same structure in animals and plants
2. Myofibrils are thin filaments more than 1 cm long with a diameter of 1 micron, located in bundles along the muscle fiber
3. Pseudopodia (perform the function of movement; due to them, muscle contraction occurs)

Similarities between plant and animal cells

The characteristics that are similar between plant and animal cells include the following:

1. Similar structure of the structure system, i.e. presence of nucleus and cytoplasm.
2. The metabolic process of substances and energy is similar in principle.
3. Both animal and plant cells have a membrane structure.
4. The chemical composition of the cells is very similar.
5. Plant and animal cells undergo a similar process of cell division.
6. Plant cells and animal cells have the same principle of transmitting the code of heredity.

Significant differences between plant and animal cells

In addition to the general features of the structure and vital activity of plant and animal cells, there are also special distinctive features of each of them.

Thus, we can say that plant and animal cells are similar to each other in the content of some important elements and some vital processes, and also have significant differences in structure and metabolic processes.

The most valuable thing a person has is his own life and the life of his loved ones. The most valuable thing on Earth is life in general. And at the basis of life, at the basis of all living organisms, are cells. We can say that life on Earth has a cellular structure. That's why it's so important to know how cells are structured. The structure of cells is studied by cytology - the science of cells. But the idea of ​​cells is necessary for all biological disciplines.

What is a cell?

Definition of the concept

Cell is a structural, functional and genetic unit of all living things, containing hereditary information, consisting of a membrane membrane, cytoplasm and organelles, capable of maintenance, exchange, reproduction and development. © Sazonov V.F., 2015. © kineziolog.bodhy.ru, 2015..

This definition of a cell, although brief, is quite complete. It reflects 3 sides of the cell’s universality: 1) structural, i.e. as a structural unit, 2) functional, i.e. as a unit of activity, 3) genetic, i.e. as a unit of heredity and generational change. An important characteristic of a cell is the presence of hereditary information in it in the form of nucleic acid - DNA. The definition also reflects the most important feature of the cell structure: the presence of an outer membrane (plasmolemma), separating the cell and its environment. AND, finally, 4 most important signs of life: 1) maintaining homeostasis, i.e. constancy of the internal environment in conditions of its constant renewal, 2) exchange with the external environment of matter, energy and information, 3) the ability to reproduce, i.e. to self-reproduction, reproduction, 4) ability to develop, i.e. to growth, differentiation and morphogenesis.

A shorter but incomplete definition: Cell is the elementary (smallest and simplest) unit of life.

A more complete definition of a cell:

Cell is an ordered, structured system of biopolymers bounded by an active membrane, forming the cytoplasm, nucleus and organelles. This biopolymer system participates in a single set of metabolic, energy and information processes that maintain and reproduce the entire system as a whole.

Textile is a collection of cells similar in structure, function and origin, jointly performing common functions. In humans, in the four main groups of tissues (epithelial, connective, muscle and nervous), there are about 200 different types of specialized cells [Faler D.M., Shields D. Molecular biology of the cell: A guide for doctors. / Per. from English - M.: BINOM-Press, 2004. - 272 p.].

Tissues, in turn, form organs, and organs form organ systems.

A living organism begins from a cell. There is no life outside the cell; outside the cell only the temporary existence of life molecules is possible, for example, in the form of viruses. But for active existence and reproduction, even viruses need cells, even if they are foreign.

Cell structure

The figure below shows the structure diagrams of 6 biological objects. Analyze which of them can be considered cells and which cannot, according to two options for defining the concept “cell”. Present your answer in the form of a table:

Cell structure under an electron microscope

Membrane

The most important universal structure of the cell is cell membrane (synonym: plasmalemma), covering the cell in the form of a thin film. The membrane regulates the relationship between the cell and its environment, namely: 1) it partially separates the contents of the cell from the external environment, 2) connects the contents of the cell with the external environment.

Core

The second most important and universal cellular structure is the nucleus. It is not present in all cells, unlike the cell membrane, which is why we put it in second place. The nucleus contains chromosomes containing double strands of DNA (deoxyribonucleic acid). Sections of DNA are templates for the construction of messenger RNA, which in turn serve as templates for the construction of all cell proteins in the cytoplasm. Thus, the nucleus contains, as it were, “blueprints” for the structure of all the proteins of the cell.

Cytoplasm

This is the semi-liquid internal environment of the cell, divided into compartments by intracellular membranes. It usually has a cytoskeleton to maintain a certain shape and is in constant motion. The cytoplasm contains organelles and inclusions.

In third place we can put all other cellular structures that can have their own membrane and are called organelles.

Organelles are permanent, necessarily present cell structures that perform specific functions and have a specific structure. Based on their structure, organelles can be divided into two groups: membrane organelles, which necessarily include membranes, and non-membrane organelles. In turn, membrane organelles can be single-membrane - if they are formed by one membrane and double-membrane - if the shell of the organelles is double and consists of two membranes.

Inclusions

Inclusions are non-permanent structures of the cell that appear in it and disappear during the process of metabolism. There are 4 types of inclusions: trophic (with a supply of nutrients), secretory (containing secretions), excretory (containing substances “to be released”) and pigmentary (containing pigments - coloring substances).

Cellular structures, including organelles ( )

Inclusions . They are not classified as organelles. Inclusions are non-permanent structures of the cell that appear in it and disappear during the process of metabolism. There are 4 types of inclusions: trophic (with a supply of nutrients), secretory (containing secretions), excretory (containing substances “to be released”) and pigmentary (containing pigments - coloring substances).

1. (plasmolemma).
2. Nucleus with nucleolus .
3. Endoplasmic reticulum : rough (granular) and smooth (agranular).
4. Golgi complex (apparatus) .
5. Mitochondria .
6. Ribosomes .
7. Lysosomes . Lysosomes (from the gr. lysis - “decomposition, dissolution, disintegration” and soma - “body”) are vesicles with a diameter of 200-400 microns.
8. Peroxisomes . Peroxisomes are microbodies (vesicles) 0.1-1.5 µm in diameter, surrounded by a membrane.
9. Proteasomes . Proteasomes are special organelles for breaking down proteins.
10. Phagosomes .
11. Microfilaments . Each microfilament is a double helix of globular actin protein molecules. Therefore, the actin content even in non-muscle cells reaches 10% of all proteins.
12. Intermediate filaments . They are a component of the cytoskeleton. They are thicker than microfilaments and have a tissue-specific nature:
13. Microtubules . Microtubules form a dense network in the cell. The microtubule wall consists of a single layer of globular subunits of the protein tubulin. A cross section shows 13 of these subunits forming a ring.
14. Cell center .
15. Plastids .
16. Vacuoles . Vacuoles are single-membrane organelles. They are membrane “containers”, bubbles filled with aqueous solutions of organic and inorganic substances.
17. Cilia and flagella (special organelles) . They consist of 2 parts: a basal body located in the cytoplasm and an axoneme - a growth above the surface of the cell, which is covered on the outside with a membrane. Provide cell movement or movement of the environment above the cell.