Disaccharides are a type of complex carbohydrate consisting of two monosaccharide molecules bonded together via a glycosidic bond. Monosaccharides are the basic units of carbohydrates that cannot be hydrolyzed into simpler monosaccharides.
What’s that
Disaccharides (disahkaran) are chemical compounds which are complexes of two monosaccharide molecules (chemical compounds that have a functional group -OH at the end) connected by a functional group -CO- between the molecules. Disaccharides are generally referred to as sugars, and are used by organisms as an energy source and raw material provider to form other compounds.
Monosaccharides generally are glucose, galactoza, and mannose. Disaccharides formed from glucose are called sugars, and consist of two glucose molecules joined by a functional group -CO-. Examples of disaccharides formed from glucose are maltose (wheat sugar), sucrose (ant sugar), and lactose (galactose sugar).
The disaccharide formed from galactoza is called galactoside, and consists of one galactoza molecule and one other monosaccharide molecule. Examples of galactoside are lactose (galactose sugar) and gentianin (galactose sugar which is used as a raw material to produce color on roof tiles).
The disaccharide formed from mannose is called a mannoside, and consists of one mannose molecule and one other monosaccharide molecule. An example of a mannoside is fructomannan (a disaccharide polymer formed from fructose and mannose) which is used as a raw material to produce color in fruit.
Biological Functions
Disaccharides also have other biological functions, including:
- Forming structures: Disaccharides are used by organisms to form structures such as cellulose (a disaccharide polymer formed from glucose) in celluloid (cells).
- Forming other compounds: Disaccharides are used by organisms to form other compounds such as starch (a disaccharide polymer formed from glucose) in the bodies of animals and plants.
- Helps biological processes: Disaccharides are used by enzymes in biological processes such as digestion (food processing process).
Summary
Some things you need to know about disaccharides are:
- Structure: Disaccharides are formed when two monosaccharide molecules, such as glucose, fructose, or galactose, combine through a dehydration reaction. For example, sucrose is formed from one glucose molecule and one fructose molecule bonded together.
- Function: Disaccharides are an important source of energy in food. When consumed, enzymes in our body will hydrolyze disaccharides into simpler monosaccharides, such as glucose, to be used as an energy source by body cells.
- Examples of Disaccharides: Some examples of disaccharides that are commonly found are sucrose (cane sugar or granulated sugar), lactose (milk sugar), and maltooligosaccharides (starch degradation products).
- Role in Digestion: In humans, digestion of disaccharides begins in the mouth with the help of the enzyme amylase from saliva. Then, in the small intestine, enzymes such as sucrase, lactase, and maltase break down disaccharides into simpler monosaccharides so they can be absorbed by the body.
- Food Sources: Disaccharides can be found in foods such as fruits, vegetables, and dairy products. Sucrose is generally found in granulated sugar, while lactose can be found in milk and milk products.
In summary, disaccharides are a type of complex carbohydrate consisting of two monosaccharide molecules bonded together. Disaccharides have an important role as an energy source in food and can be found in various food sources.