Carbohydrates

Carbohydrates List

Introduction

Compounds containing carbon, hydrogen, and oxygen are known as carbohydrates, also referred to as saccharides. Carbohydrates are characterized by the presence of multiple hydrogen atoms or hydroxyl groups attached to a chain of carbon atoms. They are the most abundant organic molecules in nature. In carbohydrates, the ratio of oxygen to hydrogen is the same as in water, and the general formula is C_x(H₂O)_y, reflecting their composition. Carbohydrates serve as the primary source of energy for all organisms, sustaining vital life activities. At the most fundamental level, monosaccharides (Fig. 1) are the most basic units from which all carbohydrates are built.

Fig. 1 Chemical structures of monosaccharides

Classification of Carbohydrates

Saccharides are the basic unit structure or building block of carbohydrates. Carbohydrates can be classified into monosaccharides, disaccharides, oligosaccharides and polysaccharides according to the number of saccharide units they contain.

• Monosaccharides

Monosaccharides are carbohydrates containing one saccharide unit that cannot be further hydrolyzed. According to the type of carbonyl groups, monosaccharides can be divided into aldoses and ketoses. Besides, according to the number of carbon atoms in the molecule, they can also be classified into trioses, tetroses, pentoses, hexoses, and heptoses. The most common monosaccharides are glucose, fructose and galactose.

• Disaccharides

Disaccharides are carbohydrates formed by two molecules of saccharide units through glycosidic bonds such as the N-glycosidic bond and the O-glycosidic bond. A disaccharide can be hydrolyzed to produce two identical or different monosaccharide molecules. The most common disaccharides are maltose, sucrose and lactose. Hydrolysis of sucrose produces glucose and fructose. Maltose consists of two α-D-glucose, while lactose consists of two β-D-glucose linked by oxide bonds.

• Oligosaccharides

Oligosaccharides are carbohydrates containing 3-10 saccharide units. They are often covalently bound to proteins or lipids in the form of glycoproteins or glycolipids. The main characteristics of oligosaccharides are difficult to be digested and absorbed by the gastrointestinal tract, low sweetness, low calories, and basically do not increase blood sugar levels or blood cholesterol levels. Raffinose and stachyose are common oligosaccharides.

• Polysaccharides

Polysaccharides, also known as "glycans", are carbohydrates containing more than 10 saccharide units. Different polysaccharides differ in the recurring saccharide units, the length of the chains, the type of bonding units, and the branching degree. Depending on the type of saccharide units, they can be further classified into homopolysaccharides and heteropolysaccharides. Common polysaccharides are starch, glycogen and cellulose.

Fig. 2 Classification of carbohydrates.

Functions

Carbohydrates serve multiple essential functions in the human body, which are listed below.

• Support for Gut Health: Certain carbohydrates, such as dietary fiber or prebiotics, are not digestible by human enzymes but serve as food for beneficial gut bacteria. These bacteria ferment fiber in the colon, producing short-chain fatty acids that promote gut health.

Alfa Chemistry offers a wide range of carbohydrates, encompassing monosaccharides, disaccharides, oligosaccharides, and polysaccharides. For a comprehensive view of our product catalog, kindly access the link provided at the top of this page. If you do not find the product you need, please do not hesitate to contact us.