Carbohydrates- Definition, Structure, Types, Examples, Functions


Carbohydrates are organic molecules of carbon, hydrogen, and oxygen atoms in a fixed ratio. The general formula for carbohydrates is (CH2O)n, where n is the number of carbon atoms. Carbohydrates are one of the four major classes of biomolecules, along with proteins, lipids, and nucleic acids.

Carbohydrates are also known as saccharides, which means "sugars" in Greek. The name reflects their sweet taste and role as the primary energy source for living organisms. Carbohydrates can be classified into three main types based on their size and complexity: monosaccharides, oligosaccharides, and polysaccharides.

Monosaccharides are the simplest and smallest carbohydrates with only one sugar unit. They have the general formula CnH2nOn, where n can range from 3 to 7. Examples of monosaccharides include glucose, fructose, and ribose.

Oligosaccharides are carbohydrates that consist of two to ten monosaccharide units linked by glycosidic bonds. They have the general formula Cn(H2O)n-1, where n is the number of monosaccharide units. Examples of oligosaccharides include sucrose, lactose, and raffinose.

Polysaccharides are carbohydrates with more than ten monosaccharide units linked by glycosidic bonds. They have no general formula, as they can vary in their structure and composition. Examples of polysaccharides include starch, glycogen, cellulose, and chitin.

Carbohydrates have diverse functions in living organisms. They serve as energy sources, energy storage molecules, structural components, signaling molecules, and precursors for other biomolecules. Carbohydrates also play important roles in metabolism, cell recognition, immunity, and gene expression.