6.1. Digestion, Absorption and Transport of Dietary Carbohydrates. Disorders of Digestion and Absorption of Carbohydrates
There are dozens of different monosaccharides and lots of different oligoand polysaccharides in a human body. Carbohydrates are a part of live organisms and together with proteins, lipids and nucleic acids determine the specificity of their structure and functioning. Carbohydrates are the major fuel source since about half of all energy requirements of human are satisfied from the oxidation of carbohydrates. The leading role in fuel metabolism belongs to glucose and glycogen. Carbohydrates are a part of structural and functional components of cells. They include pentoses of nucleotides and nucleic acids, carbohydrates of glycolipids and glycoproteins, heteropolysaccharides of the extracellular matrix. A large number of proteins, such as enzymes, transport proteins, receptors and hormones are glycoproteins in which carbohydrate components increase protein specificity. Lipids and some amino acids can be synthesized from carbohydrates. Thus, carbohydrates perform diverse functions, and each of them is vital for an organism. The use of carbohydrates as an energy source has great significance for an organism.