Which of the following functions is performed by the cell cytoplasm? What are the functions of ribosomes? Are there differences in the cytoplasm of plant and animal cells?

Along with the cytoplasm is one of the main parts of the cell, this building material any organic matter. Cytoplasm plays a very important role in the life of a cell. important role, she unites everything cellular structures, promotes their interaction with each other. Also in the cytoplasm is the cell nucleus and that’s it. If we talk in simple words, then the cytoplasm is the substance in which all other components of the cell are located.

The structure of the cytoplasm

The cytoplasm contains various chemical compounds, which are not homogeneous Chemical substance, but a complex physico-chemical system, it is also constantly changing and developing and has a high water content. An important component cytoplasm is a protein mixture in a colloidal state combined with nucleic acids, fats and carbohydrates.

The cytoplasm is also divided into two components:

• endoplasm
• exoplasm.

Endoplasm is located in the center of the cell and has a more fluid structure. It is in it that all the most important organelles of the cell are located. Exoplasm is located along the perimeter of the cell, where it borders on its membrane; it is more viscous and dense in consistency. It plays a connecting role between the cell and environment.

Drawing of the cytoplasm.

Functions of the cytoplasm

What function does the cytoplasm perform? Very important - all processes of cellular metabolism take place in the cytoplasm, with the exception of synthesis nucleic acids(it occurs in the cell nucleus). In addition to this most important function, the cytoplasm plays the following useful roles:

• fills the cell cavity
• is a connecting link for cellular components,
• determines the position of organelles,
• is a conductor for physical and chemical processes at the intracellular and intercellular levels,
• maintains the internal pressure of the cell, its volume, elasticity, etc.

Movement of the cytoplasm

The ability of the cytoplasm to move is an important property; this ensures the connection of cell organelles. In biology, the movement of the cytoplasm is called cyclosis, it is a constant process. The movement of cytoplasm in a cell can be streamlike, oscillatory or circular.

Cytoplasmic division

Another property of the cytoplasm is its division, without which cell division itself would be simply impossible. The division of the cytoplasm is carried out by

Cytoplasm is called the internal environment of the body because it is constantly moving and moves all cellular components. The cytoplasm constantly undergoes metabolic processes and contains all organic and non-organic substances.

Structure

Cytoplasm consists of a permanent liquid part - hyaloplasm and elements that change - organelles and inclusions.

Organelles of the cytoplasm are divided into membrane and non-membrane, the latter in turn can be double-membrane and single-membrane.

1. Non-membrane organelles: ribosomes, vacuoles, centrosome, flagella.
2. Double membrane organelles: mitochondria, plastids, nucleus.
3. Single-membrane organelles: Golgi apparatus, lysosomes, vacuoles, endoplasmic reticulum.

Also components of the cytoplasm include cellular inclusions, are presented in the form of lipid droplets or glycogen granules.

The main features of the cytoplasm:

• Colorless;
• elastic;
• mucous-viscous;
• structured;
• movable.

The liquid part of the cytoplasm in its own way chemical composition differs in cells of different specializations. The main substance is water from 70% to 90%; it also contains proteins, carbohydrates, phospholipids, trace elements, and salts.

The acid-base balance is maintained at 7.1–8.5pH (slightly alkaline).

Cytoplasm, when studied at high magnification of a microscope, is not a homogeneous medium. There are two parts - one is located on the periphery in the area of ​​the plasmalemma (ectoplasm), the other is near the core (endoplasm).

Ectoplasm serves as a link with the environment, intercellular fluid and neighboring cells. Endoplasm- This is the location of all organelles.

The structure of the cytoplasm contains special elements - microtubules and microfilaments.

Microtubules– non-membrane organelles necessary for the movement of organelles within the cell and the formation of the cytoskeleton. The globular protein tubulin is the main building block for microtubules. One tubulin molecule does not exceed 5 nm in diameter. In this case, the molecules are able to combine with each other, together forming a chain. 13 such chains form a microtubule with a diameter of 25 nm.

Tubulin molecules are in constant motion to form microtubules; if the cell is exposed to unfavorable factors, the process is disrupted. Microtubules are shortened or completely denatured. These elements of the cytoplasm are very important in the life of plant and bacterial cells, as they take part in the structure of their membranes.

Microfilaments- These are submicroscopic non-membrane organelles that form the cytoskeleton. They are also part of the contractile apparatus of the cell. Microfilaments consist of two types of proteins - actin and myosin. Actin fibers are thin up to 5 nm in diameter, and myosin fibers are thick – up to 25 nm. Microfilaments are mainly concentrated in the ectoplasm. There are also specific filaments that are characteristic of a particular cell type.

Microtubules and microfilaments together form the cell cytoskeleton, which ensures the interconnection of all organelles and intracellular metabolism.

High molecular weight biopolymers are also isolated in the cytoplasm. They are combined into membrane complexes that permeate the entire internal space of the cell, determine the location of organelles, and delimit the cytoplasm from the cell wall.

The structural features of the cytoplasm lie in the ability to change its internal environment. It can exist in two states: semi-liquid ( sol) and viscous ( gel). So, depending on the influence external factors(temperature, radiation, chemical solutions), the cytoplasm changes from one state to another.

Functions

• Fills the intracellular space;
• connects everything structural elements cells;
• transports synthesized substances between organelles and outside the cell;
• establishes the location of organelles;
• is a medium for physical and chemical reactions;
• responsible for cell turgor, the constancy of the internal environment of the cell.

The functions of the cytoplasm in a cell also depend on the type of cell itself: plant, animal, eukaryotic or prokaryotic. But in all living cells, an important physiological phenomenon occurs in the cytoplasm - glycolysis. The process of glucose oxidation, which occurs under aerobic conditions and ends with the release of energy.

Movement of the cytoplasm

The cytoplasm is in constant motion; this characteristic is of great importance in the life of the cell. Thanks to movement it is possible metabolic processes inside the cell and distribution of synthesized elements between organelles.

Biologists observed the movement of cytoplasm in large cells, while monitoring the movement of vacuoles. Microfilaments and microtubules, which are activated in the presence of ATP molecules, are responsible for the movement of the cytoplasm.

The movement of the cytoplasm shows how active the cells are and how capable they are of survival. This process depends on external influences, therefore the slightest changes in surrounding factors stop or accelerate it.

The role of the cytoplasm in protein biosynthesis. Protein biosynthesis is carried out with the participation of ribosomes, which are located directly in the cytoplasm or on the granular ER. Also via nuclear pores mRNA enters the cytoplasm, which carries information copied from DNA. The exoplasm contains the necessary amino acids for protein synthesis and enzymes that catalyze these reactions.

Summary table of the structure and functions of the cytoplasm

Structural elements	Structure	Functions
Ectoplasm	Dense layer of cytoplasm	Provides connection with the external environment
Endoplasm	More fluid layer of cytoplasm	Location of cell organelles
Microtubules	Constructed from a globular protein - tubulin with a diameter of 5 nm, which is capable of polymerization	Responsible for intracellular transport
Microfilaments	Composed of actin and myosin fibers	Form the cytoskeleton, maintain connections between all organelles

The gel-like contents of the cell, bounded by a membrane, are called the cytoplasm of a living cell. The concept was introduced in 1882 by the German botanist Eduard Strassburger.

Structure

Cytoplasm is the internal environment of any cell and is characteristic of cells of bacteria, plants, fungi, and animals.
Cytoplasm consists of the following components:

• hyaloplasm (cytosols) - liquid substance;
• cellular inclusions - optional components of the cell;
• organelles - permanent components of the cell;
• cytoskeleton - cell framework.

The chemical composition of the cytosol includes the following substances:

• water - 85%;
• proteins - 10%
• organic compounds - 5%.

TO organic compounds relate:

• mineral salts;
• carbohydrates;
• lipids;
• nitrogen-containing compounds;
• a small amount of DNA and RNA;
• glycogen (characteristic of animal cells).

Rice. 1. Composition of the cytoplasm.

The cytoplasm contains a supply of nutrients (drops of fat, grains of polysaccharides), as well as insoluble waste products of the cell.

The cytoplasm is colorless and constantly moves and flows. It contains all the organelles of the cell and mediates their interconnection. When partially removed, the cytoplasm is restored. When the cytoplasm is completely removed, the cell dies.

The structure of the cytoplasm is heterogeneous. Conditionally allocate two layers of cytoplasm:

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• ectoplasm (plasmagel) - an outer dense layer that does not contain organelles;
• endoplasm (plasmasol) - an internal, more liquid layer containing organelles.

The division into ectoplasm and endoplasm is clearly expressed in protozoa. Ectoplasm helps the cell move.

Outside, the cytoplasm is surrounded cytoplasmic membrane or plasmalemma. It protects the cell from damage, carries out selective transport of substances and provides cell irritability. The membrane consists of lipids and proteins.

Life activity

Cytoplasm is a vital substance involved in the main processes of the cell:

• metabolism;
• growth;
• division.

The movement of the cytoplasm is called cyclosis or cytoplasmic flow. It occurs in eukaryotic cells, including humans. During cyclosis, the cytoplasm delivers substances to all organelles of the cell, carrying out cellular metabolism. The cytoplasm moves through the cytoskeleton with the consumption of ATP.

As the volume of cytoplasm increases, the cell grows. The process of dividing the body of a eukaryotic cell after nuclear division (karyokinesis) is called cytokinesis. As a result of body division, the cytoplasm along with organelles is distributed between two daughter cells.

Rice. 2. Cytokinesis.

Functions

The main functions of the cytoplasm in a cell are described in the table.

The separation of the cytoplasm from the membrane by osmosis of water coming out is called plasmolysis. The reverse process - deplasmolysis - occurs when a sufficient amount of water enters the cell. The processes are characteristic of any cell except animal cells.

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The concept of cytoplasm was introduced back in 1882. It is known that the cytoplasm is the internal environment of the cell. In this article we will look at what cytoplasm is, what is included in its structure and what its contents are.

We will also answer the question of what functions the cytoplasm performs.

Concept of cytoplasm

Cytoplasm is usually understood as the internal environment of living or dead cell. In this case, the cytoplasm does not include the nucleus and vacuoles. Cytoplasm includes hyaloplasm, which is a transparent substance and organelles, and also includes so-called inclusions. Inclusions are various non-permanent structures, these include, for example, cell waste products, various secretions, and pigments.

Composition of the cytoplasm

The structure of the cytoplasm is a combination of organic and inorganic substances. The main substance that makes up the cytoplasm is water. The cytoplasm also contains true and colloidal solutions. The true solution is formed by mineral salts, glucose and amino acids. The colloidal solution contains proteins. Insoluble waste and nutrient reserves can also be found in the structure of the cytoplasm.

Functions of the cytoplasm

Most important functions The cytoplasm is the unification of cellular structures, as well as ensuring their interaction. In addition, the cytoplasm, thanks to constant movement and flow inside the cell provides movement various substances, which contributes to the nutrition of all organelles and organelles. It also provides turgor (stressed state) of the cell.

Cytoplasm is the contents of a cell outside the nucleus, enclosed in a plasma membrane. It has a transparent color and gel-like consistency. The cytoplasm is composed primarily of water and also contains enzymes, salts, and various organic molecules.

Function of the cytoplasm

The cytoplasm functions to support and suspend organelles and cellular molecules. Many cellular processes also occur in the cytoplasm.

Some of these processes include protein synthesis, the first stage known as glycolysis, and. In addition, the cytoplasm helps move substances such as hormones around the cell and also dissolves cellular waste.

Components of the cytoplasm

Organelles

Organelles are tiny cellular structures that perform specific functions within the cell. Examples of organelles include: , and .

Also located inside the cytoplasm is a network of fibers that help the cell maintain its shape and provide support for organelles.

Cytoplasmic inclusions

Cytoplasmic inclusions are particles temporarily suspended in the cytoplasm. Inclusions consist of macromolecules and granules.

The three types of inclusions found in the cytoplasm are secretory and nutrient inclusions, and pigment granules. Examples of secretory inclusions are proteins, enzymes and acids. Glycogen (the storage of glucose molecules) and lipids are examples of nutrient inclusions. Melanin, present in skin cells, is an example of the inclusion of pigment granules.

Cytoplasmic compartments

Cytoplasm can be divided into two main parts: endoplasm and ectoplasm. Endoplasm is the central region of the cytoplasm that contains organelles. Ectoplasm is the more gel-like peripheral portion of the cell's cytoplasm.

Cell membrane

The cell or plasma membrane is a structure that prevents cytoplasm from leaking out of the cell. This membrane is composed of phospholipids that form a lipid bilayer that separates the cell contents from the extracellular fluid. The lipid bilayer is semipermeable, meaning that only some molecules are able to diffuse across the membrane to enter or exit the cell. Extracellular fluid, proteins, lipids and other molecules can be added to the cell cytoplasm using. In this process, molecules and extracellular fluid are internalized as the membrane forms a vesicle.

The vesicle separates fluid, molecules, and buds from the cell membrane to form an endosome. The endosome moves within the cell to deliver its contents to the appropriate destinations. Substances are removed from the cytoplasm by. In this process, vesicles budding from Golgi bodies fuse with cell membrane, displacing their contents from the cell. Plasma membrane also provides structural support to the cell, acting as a stable platform for the attachment of the cytoskeleton and.