Structure and main functions of cells

Cells, like the bricks of a house, are the building material of almost all living organisms. What parts do they consist of? What function do various specialized structures perform in a cell? You will find answers to these and many other questions in our article.

What is a cell

A cell is the smallest structural and functional unit of living organisms. Despite its relatively small size, it forms its own level of development. Examples of single-celled organisms are the green algae Chlamydomonas and Chlorella, the protozoa Euglena, amoeba and ciliates. Their sizes are truly microscopic. However, the function of the body cell of a given systematic unit is quite complex. These are nutrition, breathing, metabolism, movement in space and reproduction.

General plan of cell structure

Not all living organisms have a cellular structure. For example, viruses are formed by nucleic acids and a protein shell. Plants, animals, fungi and bacteria are made up of cells. They all differ in structural features. However, their general structure is the same. It is represented by the surface apparatus, internal contents - cytoplasm, organelles and inclusions. The functions of cells are determined by the structural features of these components. For example, in plants, photosynthesis occurs on the inner surface of special organelles called chloroplasts. Animals do not have these structures. The structure of the cell (the table “Structure and Functions of Organelles” examines all the features in detail) determines its role in nature. But all multicellular organisms have in common the provision of metabolism and interconnection between all organs.

Cell structure: table "Structure and functions of organelles"

This table will help you familiarize yourself in detail with the structure of cellular structures.

As you can see, each cellular organelle has its own complex structure. Moreover, the structure of each of them determines the functions performed. Only the coordinated work of all organelles allows life to exist at the cellular, tissue and organismal levels.

Basic functions of the cell

A cell is a unique structure. On the one hand, each of its components plays its role. On the other hand, the functions of the cell are subordinated to a single coordinated operating mechanism. It is at this level of life organization that the most important processes take place. One of them is reproduction. It is based on a process. There are two main ways of doing it. So, gametes are divided by meiosis, all others (somatic) are divided by mitosis.

Due to the fact that the membrane is semi-permeable, various substances can enter the cell in the opposite direction. The basis for all metabolic processes is water. Upon entering the body, biopolymers are broken down into simple compounds. But minerals are found in solutions in the form of ions.

Cellular inclusions

Cell functions would not be fully realized without the presence of inclusions. These substances are a reserve of organisms for unfavorable periods. This could be drought, low temperature, or insufficient oxygen. The storage functions of substances in plant cells are performed by starch. It is found in the cytoplasm in the form of granules. In animal cells, glycogen serves as a storage carbohydrate.

What are fabrics

Cells that are similar in structure and function are united into tissues. This structure is specialized. For example, all cells of epithelial tissue are small and tightly adjacent to each other. Their shape is very diverse. This fabric is practically absent. This structure resembles a shield. Thanks to this, epithelial tissue performs a protective function. But any organism needs not only a “shield”, but also a relationship with the environment. To carry out this function, the epithelial layer has special formations - pores. And in plants, a similar structure is the stomata of the skin or lentils of the cork. These structures carry out gas exchange, transpiration, photosynthesis, and thermoregulation. And above all, these processes are carried out at the molecular and cellular level.

Relationship between cell structure and function

The functions of cells are determined by their structure. All fabrics are a clear example of this. Thus, myofibrils are capable of contraction. These are muscle tissue cells that carry out the movement of individual parts and the entire body in space. But the connecting one has a different structural principle. This type of tissue consists of large cells. They are the basis of the entire organism. Connective tissue also contains a large amount of intercellular substance. This structure ensures its sufficient volume. This type of tissue is represented by such varieties as blood, cartilage, and bone tissue.

They say that they are not restored... There are many different views on this fact. However, no one doubts that neurons connect the entire body into a single whole. This is achieved by another structural feature. Neurons consist of a body and processes - axons and dendrites. Through them, information flows sequentially from the nerve endings to the brain, and from there back to the working organs. As a result of the work of neurons, the entire body is connected by a single network.

So, most living organisms have a cellular structure. These structures are the building blocks of plants, animals, fungi and bacteria. The general functions of cells are the ability to divide, perceive environmental factors and metabolism.