1, monosaccharide: sugar that cannot be hydrolyzed into smaller molecules. Common monosaccharides are glucose (ch2oh-choh-choh-choh-choh-choh-choh), fructose (ch2oh-choh-choh-co-ch2oh), ribose (ch2oh-choh-choh-choh-choh-choh) and deoxyribose (ch2oh-choh-choh-choh-choh-choh).

2. Polysaccharide: It is condensed from hundreds or even tens of thousands of monosaccharide molecules, and the general formula is (C6H 10O5)n, and the most important ones are starch and cellulose. Homogeneous polysaccharide: starch, glycogen, cellulose, hemicellulose and chitin; Heteropolysaccharide: glycosaminoglycan (hyaluronic acid, chondroitin sulfate, dermatan sulfate, etc. ).

3. Binding sugar: also known as complex carbohydrate, sugar conjugates, including glycolipids, glycoproteins (proteoglycans), sugar-nucleotides, etc.

4. Aldose: The C atom with the highest oxidation number (named C- 1) in this monosaccharide is an aldehyde group, which has the properties of alcohol and aldehyde.

5. Ketose: A monosaccharide in which the C atom with the highest oxidation value (called C-2) is a keto group.

Extended data:

Sugar can also be divided into triose, special sugar, pentose and hexose according to the number of carbon atoms. The simplest sugar is triose (glyceraldehyde and dihydroxyacetone). Because most carbohydrates can be represented by the general formula Cn (H2O)n, people used to think that sugar is a compound of carbon and water, which is called carbohydrate.

It is found that some sugars, such as rhamnose (C6H 12O5) and deoxyribose (C5H 10O4), do not conform to the general formula of carbohydrates. In addition, the ratio of the number of hydrogen atoms to oxygen atoms in some organic compounds is exactly 2: 1, such as formaldehyde (CH2O) and acetic acid (C2H4O2), which conforms to the definition of carbohydrate, but not sugar. Therefore, it is inappropriate to call sugar carbohydrate, but it has been used for a long time and is still used by people today.

References:

Baidu encyclopedia-sugar