disaccharide
Definition
- Noun:
- A disaccharide is a type of sugar (carbohydrate) composed of two monosaccharide molecules linked together. It is broken down into these two simpler sugar units during digestion or chemical hydrolysis.
Usage
- Disaccharide is a scientific term used primarily in chemistry, biochemistry, nutrition, and biology.
- It functions as a countable noun (e.g., , ).
Examples
- Noun:
- Sucrose, or table sugar, is a common disaccharide composed of glucose and fructose.
- Lactose, the sugar found in milk, is a disaccharide that some people have difficulty digesting.
- The enzyme lactase breaks down the disaccharide lactose in the small intestine.
Advanced Usage
- Disaccharides are classified as simple carbohydrates and serve as an important source of energy in the human diet.
- The chemical bond linking the two monosaccharides in a disaccharide is called a glycosidic bond.
Variants and Related Words
- Monosaccharide (n): A simple sugar that cannot be hydrolyzed to give a simpler sugar; the building block of a disaccharide (e.g., glucose, fructose).
- Polysaccharide (n): A carbohydrate whose molecules consist of a large number of monosaccharide units bonded together (e.g., starch, cellulose).
- Carbohydrate (n): A broader category of organic compounds that includes sugars, starches, and cellulose, to which disaccharides belong.
- Oligosaccharide (n): A carbohydrate whose molecules are composed of a relatively small number (typically three to ten) of monosaccharide units.
Synonyms
- Double sugar: A less technical synonym for disaccharide.
- Simple sugar: A broader category that includes both monosaccharides and disaccharides.
Related Phrases / Terms
- Hydrolysis of a disaccharide: The chemical process of breaking a disaccharide into its two constituent monosaccharides by reaction with water.
- The hydrolysis of the disaccharide sucrose yields glucose and fructose.
Noun
- any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis
