Biochemistry

Mucopolysaccharides are gelatinous, sticky substances. They perform various functions, including structural, protective, regulatory. Mucopolysaccharides make up the bulk of the intercellular substance of tissues , are part of the skin, cartilage, synovial fluid. In the body, mucopolysaccharides are found zn combination with proteins (glycoproteins) and fats (glycolipids). In plants, they are represented by gums. The most common heteropolysaccharides are hyaluronic acid , chondroitin sulfuric acid, heparin, sialic acids . Hyaluronic acid is a part of connective tissue as the main “ cementing ” component of cells and intercellular substance. In this regard, she plays an important role in the formation of the barrier functions of the body, which helps to protect it from infections, ionizing radiation, it also participates in the exchange of water in the body. Hyaluronic acid breaks down under the action of a specific enzyme hyaluronidase , which is found in tissues. This leads to a disruption in the structure of the intercellular substance, “ cracks ” are found in its composition and permeability to water and other substances increases. This enzyme is found in bee and snake venoms, sperm. Some bacteria also contain hyaluronidase, which facilitates their penetration into the cell. In a number of diseases, especially in radiation sickness, the breakdown of hyaluronic acid is enhanced, which weakens the function of connective tissue and increases the permeability of cell membranes. This increases the likelihood of microflora entering the body. Chondroitinsulfuric acid is a high molecular weight compound. It is part of the cartilage and bone tissue in the form of complexes with collagen protein and performs supporting functions. In addition, chondroitinsulfuric acid is involved in the regulation of permeability of cell membranes, contributes to the deposition of calcium in the bones. Heparin is found in the liver, lungs, and walls of large vessels. In the blood, it binds to proteins and prevents blood coagulation, performing the function of an anticoagulant . In addition, heparin has an anti-inflammatory effect , affects the metabolism ofpotassium and sodium, performs an antitoxic function . Sialic acids. They are the structural elements of glycoproteins and glycolipids of the cell membranes of animal tissues. Sialic acids are found in saliva and other digestive juices, mucous secrets of the nasal cavity, uterus. In inflammatory diseases, the level of sialic acids increases. Hemicelluloses are heteropolysaccharides, as they are built from various monosugars. Hemicelluloses in plants accompany cellulose. During their hydrolysis, a mixture of various monosaccharides is formed ( D- galactose, D- xylose, D- arabinose, uronic acids, D- mannose, D- glucose). 153