Plastic exchange, its essence and role for the organism

Plastic metabolism is also called anabolism or assimilation and is a combination of all enzymatic biochemical reactions, as a result of which bioorganic compounds are synthesized.

Plastic metabolism involves the biosynthesis of proteins, lipids, carbohydrates, nucleic acids. In anabolism, the process of photosynthesis and chemosynthesis also passes.

If we talk about plastic metabolism in the human body, then immediately it must be said that all the nutrients that enter the body with food have a high molecular weight, so they can not be digested. In the process of digestion these compounds break down into individual monomers, which are already used for the synthesis of specific high molecular substances inherent in the human body.

One of the most important classes of compounds are proteins. The protein nature of all the enzymes of the body, as well as some hormones. The proteins are hemoglobin (provides the respiratory function), antibodies (provide the immune response of the body), actin and myosin (predetermine muscle contraction), collagen and keratin (perform a structural function in the body).

Given the important role of proteins for the functioning of the body, it is worth considering the process of their synthesis as an important part of plastic metabolism.

It must be said that all living organisms differ among themselves by the presence of specific proteins, which consist of amino acids. It is the interposition of amino acids that determines the specific properties of protein compounds.

Proteins are synthesized in the cell cytoplasm by special organelles - ribosomes. These structures consist of a large and small subunits. They take part in the processes of protein synthesis. An important role in protein biosynthesis is played by nucleic acids, which include DNA and RNA. So, the structural units of DNA (genes) contain encoded information about the primary structure of proteins (amino acid sequence), and RNA is responsible for its reading and transport of amino acids to the site where the protein is synthesized.

Synthesis of proteins occurs in two stages: transcription and translation. Transcription is based on the process of transferring information about the structure of the protein from DNA to RNA.

Translation is the direct synthesis of a polypeptide chain with a corresponding sequence of amino acids according to the genetic code with the participation of the matrix (information) RNA. The whole process of translation passes through three stages: initiation, elongation, and termination. As a result of translation, a protein with a primary structure is formed.

It is worth remembering that plastic exchange is not only the synthesis of proteins or other organic compounds, but also photosynthesis, which is a complex and multistage process, it passes in 2 phases.

The light phase is carried out in chloroplasts (on thylakoids), ATP is formed and molecular oxygen is released, and the dark phase passes in the main substance of chloroplasts and causes absorption of carbon dioxide and formation of carbohydrates.

I think we should not dwell on the role of photosynthesis, it is enough to say that this process generates about 150 billion tons of organic matter annually, as well as about 200 billion tons of oxygen.

I must say that the plastic exchange is closely related to the energy processes that occur in the body. Thus, energy metabolism (catabolism) is the opposite process of anabolism and includes all splitting reactions, when complex compounds break down into simple ones, and high-molecular substances become a number of low-molecular compounds. In this case, energy is released, which is used in the processes of plastic metabolism.

Thus, plastic and energy metabolism in the cell forms the basis of the general metabolism, which includes all the processes of synthesis and decomposition of substances.