Monosaccharides

Monosaccharides refer to molecules that cannot be simply hydrolyzed into smaller sugars. According to the position of the carbonyl group, they are divided into two categories: aldose and ketose. According to the number of carbon atoms in the monosaccharide, it can also be divided into triose, tetrose, pentose, hexose, and heptose. The most abundant monosaccharides in nature are pentoses and hexoses. Such as glyceraldehyde, a three-carbon sugar; erythrose and thulose, four-carbon sugars; arabinose, ribose, xylose, and lyxose, five-carbon sugars; glucose, mannose, fructose, and galactose, six-carbon sugars. Monosaccharides in food are mainly hexoses (six-carbon sugars).