A monosaccharide in which the aldehyde group is reduced to an alcohol. Thus D-glucose yields the sugar alcohol *sorbitol
while the alcohol from mannose is *mannitol
. Other important sugar alcohols are *glycerol
, a central compound in lipid metabolism, and *inositol
, an important intermediate in cell wall polysaccharide synthesis. Sugar alcohols, other than glycerol, are limited in nature to the plant kingdom. sugar phosphate A phosphate derivative of a monosaccharide. Sugar phosphates are important intermediates in carbohydrate metabolism. The pentose phosphate ribulose 1,5-bisphosphate reacts with carbon dioxide in the first reaction of the Calvin cycle. All the subsequent steps of the Calvin cycle also involve sugar phosphates as do the reactions of glycolysis.