carbohydrate metabolism

carbohydrate metabolism,

the sum of the anabolic and catabolic processes of the body involved in the synthesis and breakdown of carbohydrates, principally glucose, fructose, and galactose. Some of the processes are glycogenesis and glycolysis. Energy-rich phosphate bonds are produced in many metabolic reactions requiring carbohydrates.

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carbohydrate

a compound of carbon, hydrogen and oxygen, the latter two usually in the proportions of water (CH₂O)_n. They are classified into mono-, di-, tri-, poly- and heterosaccharides. Carbohydrates in food are an important and immediate source of energy for the body; 1 gram of carbohydrate yields 3.75 calories (16 kilojoules). They are present, at least in small quantities, in most foods, but the chief sources are the sugars and starches of plants. Herbivores are able to utilize the insoluble polysaccharides (crude fiber) because of bacterial conversion to volatile fatty acids by fermentation in the rumen and cecum.

Carbohydrates may be stored in the body as glycogen for future use. If they are eaten in excessive amounts they are converted to and stored as fat. Rapid ingestion of very large amounts in ruminants and horses causes carbohydrate engorgement.

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complex carbohydrate

polysaccharides containing either α- and β-type glycosidic bonds. Usually occurring in mixtures in food.

dietary carbohydrate

the carbohydrate components of food.

carbohydrate loading

depletion/repletion means of maximally loading glycogen into type II muscle for increased power of muscle contraction.

carbohydrate loss

glucose loss in urine due to diabetes mellitus or chronic renal disease.

carbohydrate metabolism

series of related enzymic reactions involved in the synthesis and catabolism of carbohydrates.

carbohydrate tolerance test

see glucose tolerance test.