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The main difference between Monosaccharide and Polysaccharide is that Monosaccharide is a simple carbohydrate with a single sugar unit whereas Polysaccharides are carbohydrates made up of a large number of monosaccharides.
Monosaccharide vs. Polysaccharide
Carbohydrates are the basic components of everyone’s diet. It provides structure and energy to living things. They are composed of carbon (C), hydrogen (H) and oxygen (O). Based on several sugar units in carbohydrate, they are divided into monosaccharides, oligosaccharides, and polysaccharides, etc. Monosaccharides are the simplest carbohydrates that are made up of single polyhydroxy aldehyde or ketone unit while polysaccharides consist of 20 or more than twenty such units. Monosaccharides are sweet and cannot be hydrolyzed whereas polysaccharides are not sweet and can be hydrolyzed. For example, sugar is a monosaccharide, but cellulose is a polysaccharide.
What is Monosaccharide?
Mono means ‘single,’ and saccharin stands for‘sugars,’ hence monosaccharides are the simplest form of carbohydrates. They are made up of a single sugar unit which cannot be further hydrolyzed into simpler ones. They are insoluble in nonpolar solvents but soluble in water. They are crystalline, colorless and sweet in taste. They are made up of unbranched carbon chain in which carbon atoms are linked by a single bond. A monosaccharide may consist of aldoses or ketoses. An aldose is a sugar in which the carbonyl group (a carbon atom linked by a double bond to an oxygen atom) is present at the end of the carbon chain but, if the carbonyl group is present at any other position of the carbon chain except at the end that it is called as a ketose. Other carbons of the chain contain a hydroxyl group. Trioses, tetroses, pentoses, hexoses, and heptoses, etc. are the monosaccharides that consist of three, four, five, six or seven carbon atoms respectively. They appear in D and L form, where D is “Dextro” form while L is “Levo” form that are the mirror images of each other. Naturally occurring monosaccharides are found in D-form while L form is found in synthetically produced monosaccharides. These both types have different properties. Some examples of monosaccharides are Glucose, fructose, mannose, and galactose, etc. The molecular formula of Monosaccharide is Cn(H2O)n; Here n is the small number range from 2-10.
What is Polysaccharide?
Poly means ‘many’ and saccharin stands for ‘sugar.’ They are the type of carbohydrate that is made up of ten to thousands of monosaccharides. They are also called glycans. These are the long chains of monosaccharides units attached by glycosidic bonds and can be hydrolyzed to give simple units, i.e., oligosaccharides or monosaccharides. They have high molecular weight and differ from each other in the length of the chains, recurring of monosaccharide units, in the type of bonding and degree of branching, etc. They may have a linear or highly branched structure. Some polysaccharides are said as storage polysaccharides, e.g., starch and glycogen while others are structural polysaccharides like cellulose and chitin, etc. The Molecular formula of Polysaccharide is Cx(H2O)y; Here x is usually a big number range between 200-2500.
- Homopolysaccharides: These are the polysaccharides that are consist of the same type of monosaccharide units.
- Heteropolysaccharides: They consist of two or more different type of monosaccharides units.
- Monosaccharides are the simplest carbohydrates that are made up of single polyhydroxy aldehyde or ketone unit while polysaccharides consist of 20 or more than twenty such units attached by a glycosidic bond.
- Monosaccharides are soluble in water, but they are not soluble in nonpolar solvents whereas polysaccharides are insoluble in water.
- Monosaccharides are sweet in taste; on the other hand, polysaccharides are tasteless.
- Cn(H2O)n, is the molecular formula of monosaccharide where n is the small number range from 2-10 conversely, Cx(H2O)y is the molecular formula of polysaccharide where x is usually a big number range between 200-2500.
- Monosaccharide cannot be hydrolysed on the flip side; polysaccharide can be further hydrolysed into monosaccharides.
- Monosaccharides are reducing sugars whereas polysaccharides are non reducing sugars.
- Monosaccharides are composed of a single monomer while polysaccharides are made up of a large number of monomers.
- Monosaccharides have simple, linear and unbranched structure but polysaccharides have a complex and branched structure.
- Monosaccharides have a single ring structure. Conversely, polysaccharides have several ring structures.
- Monosaccharides are made up of bonding between carbon, oxygen, and hydrogen whereas polysaccharides are made up of a large number of monosaccharide units.
- Monosaccharides are the main source of energy and provide about four calories of energy per gram while polysaccharides act as an energy reservoir and a structural component of the cell wall.
- Glucose is an example of a monosaccharide whereas cellulose is an example of polysaccharides.
From the above discussion, it is summarized that both monosaccharides and polysaccharides are carbohydrates. Monosaccharides are the simple sugar made up of single Aldo or keto units and are sweet while polysaccharides are large sugars made up of a large number of monosaccharide units combine by glycosidic bond and are tasteless.