Chemistry > Biomolecules > 1.0 Carbohydrates
Biomolecules
1.0 Carbohydrates
2.0 Monosaccharides
3.0 Disaccharides
4.0 Polysaccharides
5.0 Amino Acids
6.0 Proteins
7.0 Classification of Vitamins
8.0 Nucleic acids
1.1 Classification
On the basis of their behavior on hydrolysis:
- Monosaccharide: A carbohydrate that cannot be hydrolyzed to simpler compounds is called monosaccharide. Ex- Glucose, Fructose, Ribose.
- Oligosaccharide: Carbohydrates, on hydrolysis, gives two to ten units of monosaccharide are called oligosaccharide. Depending on the number of monosaccharides, they provide on hydrolysis, they are further classified as:
(a) Disaccharides: On hydrolysis if two monosaccharides unit obtained, are called disaccharides. For Example:
Sucrose: On hydrolysis gives one molecule of glucose and one molecule of fructose.
Maltose: On hydrolysis gives two molecules of glucose.
(b) Trisaccharides: It yield three monosaccharide molecules on hydrolysis. For Example:
Raffinose (${C_{18}}{H_{32}}{O_{16}}$): On hydrolysis yields glucose, fructose and galactose.
(c) Tetrasaccharides
- Polysaccharide: Carbohydrates which yield a large number of monosaccharide units on hydrolysis are called polysaccharides (also called non-sugars). For Example: Starch, Cellulose, etc.
Carbohydrates are also classified as
- Reducing sugars: All those carbohydrates which reduce Fehling’s solution and tollen’s reagent are referred to as reducing sugars. For Example: All monosaccharides (whether aldose or ketose), In disaccharides, if reducing group of monosaccharides i.e., aldehydic or ketonic groups are free (as in maltose and lactose).
- Non-reducing sugars: All those carbohydrates which cannot reduce Fehling’s solution and tollen’s reagent are referred to as non-reducing sugars. For Example: In disaccharide, sucrose.
