Disaccharide formula c12n22o11 among the most widespread disaccharides are maltose, lactose and sucrose.
Sucrose, or cane sugar, is synthesized in plants. Maltose is formed from starch during its digestion in animals. Lactose, or milk sugar, is found only in milk.
Polysaccharides (simple) are formed as a result of the condensation reaction of a large number of monosaccharides. Simple polysaccharides include starch (synthesized in plants), glycogen (found in liver cells and muscles of animals and humans), cellulose (forms a cell wall in plants).
Complex polysaccharides are formed as a result of the interaction of carbohydrates with lipids. For example, glycolipids are part of membranes. Complex polysaccharides also include carbohydrate-protein compounds (glycoproteins). For example, the glycoproteins included in the composition of mucus secreted by glands jeludok - but-intestinal tract.
The functions of carbohydrates:
1. Energy: 60% of the energy the body gets the breakdown of carbohydrates. When splitting 1 g of carbohydrates, 17.6 kJ of energy is released.
Structural and support: carbohydrates are part of the plasma membrane, the shell of plant and bacterial cells.
Stocking: nutrients (glycogen, starch) are deposited in stock in cells.
Protective: secrets (mucus), secreted by various glands, protect the walls of hollow organs, bronchi, stomach, intestines from mechanical damage, harmful bacteria and viruses.
Participate in photosynthesis.
Fats and fat-like substances
Fats consist of carbon, hydrogen, oxygen. Monomers of fats are fatty acids and glycerol. The properties of fats are determined by the qualitative composition of fatty acids and their quantitative ratio. Vegetable fats are liquid (oils), animals are solid (e.g. fat). Fats are insoluble in water - it is hydrophobic compounds. Fats, combining with proteins to form lipoproteins, combining with the carbohydrates - glycolipids. Glycolipids and lipoproteins are fat - like substances.
Fat-like substances are part of the membranes of cells, membrane organelles, nervous tissue. Fats can connect with gluco - Zoi to form glycosides. For example, digitoxin glycoside - a substance used in the treatment of heart disease.
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