What does monosaccharide mean?
A monosaccharide is a simple sugar and the smallest basic unit of a carbohydrate. Unlike compounds such as sucrose or lactose, which consist of two linked monosaccharides, a monosaccharide cannot be broken down into smaller carbohydrates by hydrolysis. Familiar examples include glucose, fructose, galactose, and ribose. These molecules are important in metabolism: glucose supplies readily usable energy, while fructose and galactose participate in the transport and metabolism of carbohydrates. Monosaccharides also serve as building blocks for more complex substances, including polysaccharides, glycoproteins, glycolipids, and nucleic acids. In nutrition, the term is more technical than “simple sugar” and is used when describing the molecular structure of carbohydrates, such as the monosaccharide composition of a food or the monosaccharide units released by the digestion of starch. Its distinguishing feature is chemical rather than merely culinary: a monosaccharide is a single carbohydrate unit that cannot be divided into smaller sugar molecules without chemical reaction.
nounA simple sugar that cannot be hydrolysed into smaller carbohydrates. Monosaccharides are the basic units from which more complex sugars and other carbohydrates are built.
- Any of the simple sugars that form the basic units of carbohydrates, such as glucose, fructose, and ribose.
"Glucose is a six-carbon monosaccharide and a fundamental source of energy in living organisms."
"The enzyme breaks the polysaccharide into individual monosaccharides that the organism can absorb."
"Ribose is a five-carbon monosaccharide found in RNA and in the coenzyme adenosine triphosphate."
Used when referring to simple sugars collectively or to several individual monosaccharide units.
"Digestive enzymes release monosaccharides from carbohydrates in food."
The name means “single sugar”: monosaccharides are the building blocks from which many larger carbohydrates are assembled.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does monosaccharide come from?
The word was formed in the late 19th century from Greek mono-, meaning “single,” and saccharide, a term derived from Greek sakcharon, meaning “sugar.” The underlying Greek word also appears in related English forms such as saccharose and saccharin. Monosaccharide literally refers to a “single sugar” and distinguishes simple carbohydrates from compounds made from multiple linked sugar units.
Related word forms
How monosaccharide is actually used
The term is primarily used in biochemistry, nutrition, and food science. It is more technical than the general term “simple sugar.”
Easily confused with monosaccharide
Sucrose is a disaccharide composed of two monosaccharide units, glucose and fructose, whereas a monosaccharide is a single simple sugar unit.