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Medical Term:


Pronunciation: hem′ē-kē′tăl

Definition: RC(R′)(OH)OR″, a product of the addition of an alcohol to a ketone. In the ketose sugars, the hemiketal formation is from an attack by an internal OH on the ketone carbonyl leading to intramolecular cyclization (furanose or pyranose); the hemiketal forms of the sugars are involved in polysaccharide formation, as glycosyls or glycosides.

See Also: hemiacetal, ketal