Britannica Sources used in this answer

How are glycosidic bonds formed between monosaccharides?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A biochemical flowchart shows the metabolic pathways for carbohydrate utilization, including glycolysis, the pentose phosphate pathway, and the tricarboxylic acid (TCA) cycle. The diagram traces the conversion of glucose, fructose, and glycerol through various intermediates, leading to energy production, carbon dioxide release, and biosynthesis of amino acids and porphyrins. Key steps and branches are labeled, with colored boxes highlighting biosynthetic outputs. — Carbohydrate Pathways for the utilization of carbohydrates.

Glycosidic bonds are formed through biochemical processes that link monosaccharides together to create larger structures like disaccharides and polysaccharides.1

In biological systems, this synthesis typically involves the use of nucleoside diphosphate sugars (NDP-sugars) as activated donors. For example, in the formation of storage polysaccharides like glycogen or starch, a sugar donor such as UDP-glucose or ADP-glucose transfers a glucose unit to the terminal end of a growing polysaccharide chain. This process is catalyzed by specific enzymes, such as glycogen synthetase or amylose synthetase. Similarly, the synthesis of disaccharides like sucrose or lactose involves specific reaction sequences where sugar donors react with other monosaccharides or phosphorylated derivatives to establish the linkage.2

These bonds, which can be designated as $α$ -, $β$ -, or $α, β$ -linkages, serve as the structural connection between sugar units. Conversely, these bonds can be cleaved through hydrolysis, a process catalyzed by enzymes known as glycosidases.13