Trisaccharides are oligosaccharide

Oligosaccharide

An oligosaccharide is a saccharide polymer containing a small number of component sugars, also known as simple sugars...

s composed of three monosaccharide

Monosaccharide

Monosaccharides are the most basic units of biologically important carbohydrates. They are the simplest form of sugar and are usually colorless, water-soluble, crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose , fructose , galactose, xylose...

s with two glycosidic bonds connecting them. Similar to the disaccharide

Disaccharide

A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...

s, each glycosidic bond can be formed between any hydroxyl group on the component monosaccharides. Even if all three component sugars are the same (e.g., glucose

Glucose

Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

), different bond combinations (regiochemistry) and stereochemistry (alpha- or beta-) result in triaccharides that are diastereoisomers with different chemical and physical properties.

Examples

Trisaccharide

Unit 1

Bond

Unit 2

Bond

Unit 3 >- | Isomaltotriose

glucose

α(1→6)

glucose

α(1→6)

>- | Nigerotriose

glucose Glucose Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

α(1→3)

glucose

α(1→3)

>- | Maltotriose Maltotriose Maltotriose is a trisaccharide consisting of three glucose molecules linked with α-1,4 glycosidic bonds.It is most commonly produced by the digestive enzyme alpha-amylase on amylose in starch...

glucose

α(1→4)

glucose

α(1→4)

glucose

| α(1→3)

>- | Maltotriulose

glucose

α(1→4)

glucose

α(1→4)

>- | Raffinose Raffinose Raffinose is a trisaccharide composed of galactose, fructose, and glucose. It can be found in beans, cabbage, brussels sprouts, broccoli, asparagus, other vegetables, and whole grains. Raffinose can be hydrolyzed to D-galactose and sucrose by the enzyme α-galactosidase , an enzyme not found in the...

galactose Galactose Galactose , sometimes abbreviated Gal, is a type of sugar that is less sweet than glucose. It is a C-4 epimer of glucose....

α(1→6)

glucose

β(1→2)

>- (1→2)

fructose

β(1→2)

fructose