Ketoses classification

Monosaccharides are classified as aldoses or ketoses, respectively, depending on whether the carbonyl group is an aldehyde or a ketone. Classification into trioses, tetroses, pentoses, and hexoses, respectively, is used to indicate there are three, four, five, and six carbon atoms in the monosaccharide. Both types of prefixes are also used together, e.g., aldohexose for a six-carbon monosaccharide with an aldehyde group. 

We ve included A/-acetylneuraminic acid in the section on annino sugars and described it as a ketose. We could also call it a deoxy sugar. Locate reasons for these classifications in the structural formula. Number the carbon atoms in the nine-carbon chain. What is the configuration (d or l) at the highest numbered chirality center ... 

The colors produced from ketoses, pentoses, and uronic acids in the presence of phenols and acids as well as other reagents often are enough different from those formed from aldohexoses so that they may be used for the classification of unknown materials. The ketoses, pentoses, and uronic acids usually form colored products under conditions milder than those required for the aldohexoses. Tauber s benzidine test for pentoses and... 

The suffix -ose is used to signify a carbohydrate. Hundreds of diflFerent monosaccharides are known, each of which can generally be classified as either an aldose or a ketose. Aldoses contain an aldehyde moiety, while ketoses contain a ketone moiety. According to this classification scheme, glucose is an aldose and fiructose is a ketose. 

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