Main subjects:
6.1. Carbohydrates of the diet
6.2. Carbohydrate digestion and transport of glucose into cells
6.3. Glucose metabolism in cells
6.4. Мetabolism of glycogen
6.5. Regulation of glycogen synthesis and mobilization
6.6. Glucose catabolism
6.7. Pentosephosphate pathway of glucose metabolism
6.8. Gluconeogenesis
6.9. Regulation of glycolysis and gluconeogenesis in the liver
The carbohydrates are the components of all cellular structures. They are divided into three main groups: monosaccharides (aldoses and ketoses), oligosaccharides (disaccharides, trisaccharides etc.), and polysaccharides (homopolysaccharides and heteropolysaccharides). In the humans body carbohydrates constitute about 2% of dry body mass, but they perform many important functions:
• Energetic - glucose oxidation provides half of daily energy requirements for the body.
• Structural - many proteins are glycoproteins playing prominent role in the body (receptors, hormones, immunoglobulins, blood clotting factors, structural proteins of mineralized tissues etc.). Ribose and deoxyribose are components of nucleotides, nucleic acids, and coenzymes. Glycosaminoglycans are the basic component of extracellular matrix. The products of glucose cat-abolism are substrates for the synthesis of triacylg-lycerols, cholesterol, and some amino acids.
• Protective - hyaluronic acid takes part in the detoxification of toxic and foreign compounds; heparin plays an important role in anticoagulation.
The most important body carbohydrate is glucose. Glucose enters the body as part of the carbohydrates of the food, but it can be synthesized from some amino acids, glycerol, and lactate.
6.1. CARBOHYDRATES OF THE DIET
Daily requirements of carbohydrates are 400-500 g. Starch is the main carbohydrate of the diet, which