Doudoroff, Michael Formerly, Department of Bacteriology, University of California, Berkeley, California.
Show previous versions
- Dietary carbohydrates
- Intestinal absorption and transport
- Dissimilation of simple sugars
- Oxidative mechanisms
- Simple sugars other than glucose
- Disaccharides and polysaccharides
- Links to Primary Literature
- Additional Readings
The sum of the biochemical and physiological processes involved in the breakdown and synthesis of simple sugars, oligosaccharides, and polysaccharides, and in the transport of sugars across cell membranes and tissues. The basic chemistry of carbohydrates is metabolically important. The breakdown or dissimilation of simple sugars (particularly glucose) that occurs during carbohydrate metabolism is one of the principal sources of energy for living organisms (Fig. 1). The dissimilation may be anaerobic, as in fermentations, or aerobic, that is, respiratory. In both types of metabolism, the breakdown is accompanied by the formation of energy-rich bonds, chiefly the pyrophosphate bond of the coenzyme adenosine triphosphate (ATP), which serves as a coupling agent between different metabolic processes. In higher animals, glucose is the carbohydrate constituent of blood, which carries it to the tissues of the body. In higher plants, the disaccharide sucrose is often stored and transported by the tissues. Certain polysaccharides, especially starch and glycogen, are stored as endogenous food reserves in the cells of plants, animals, and microorganisms. Others, such as cellulose, chitin, and bacterial polysaccharides, serve as structural components of cell walls. As constituents of plant and animal tissues, various carbohydrates become available to those organisms that depend on other living or dead organisms for their source of nutrients. All naturally occurring carbohydrates can be dissimilated by some animals or microorganisms. See also: Adenosine triphosphate (ATP); Biochemistry; Blood; Carbohydrate; Cellulose; Energy metabolism; Glucose; Glycogen; Metabolism; Nutrition; Oligosaccharide; Polysaccharide; Starch; Sugars (sweeteners)
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Its dedicated editorial team is led by Sagan Award winner John Rennie. Contributors include more than 9000 highly qualified scientists and 39 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 17,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information