Difference Between Cellulose and Hemicellulose        

Key Difference – Cellulose vs Hemicellulose
 

Cellulose and hemicellulose are two types of natural polymers that are mainly found in the plant cell walls and are important components of natural lignocellulosic materials. But, these two components are different in the chemical composition and the structure. The key difference between cellulose and hemicellulose is that cellulose is an organic polysaccharide molecule whereas hemicellulose is a matrix of polysaccharides.

What is Cellulose

Cellulose is an organic polysaccharide molecule with the molecular formula (C₆H₁₀O₅)_n. It has a linear chain of several hundred to thousands of D-glucose units. Cellulose is a natural polymeric compound found in many natural materials; for instance, it is the structural component of the primary cell wall in green plants. It can be also found in many forms of algae species. Cellulose is the commonest organic polymer on Earth. Many natural compounds are rich in cellulose; for example, the cellulose content of wood, cotton fiber, and dried hemp are 40–50%, 90%, and 57% respectively.

What is Hemicellulose

Hemicellulose, also known as polyose, is a matrix of polysaccharides, such as arabinoxylans, that exist along with cellulose in almost all the plant cell walls. It is a polysaccharide that is present in the biomass of most plants; about 20%-30% dry weight of plants. Hemicellulose, combined with cellulose, provides physical and structural strength to the cell wall. In addition to glucose, the other structural components in hemicelluloses are xylose, galactose, mannose, rhamnose, and arabinose. Hemicellulose has shorter chains of 500 and 3000 sugar units with a branched structure.

What is the difference between Cellulose and Hemicellulose?

Structure:

Cellulose: Cellulose is an un-branched polymeric molecule and has 7,000–15,000 glucose molecules per polymer.

Hemicellulose: Hemicellulose contains shorter chains of 500–3,000 sugar units and it is a branched polymer.

Chemical Composition:

Properties:

Cellulose: Cellulose has a strong, crystalline structure and it is resistant to hydrolysis. In contrast to hemicellulose, this has a high molecular weight. Cellulose acts as the supporting material in the plant cell walls.

Hemicellulose: Hemicellulose has a random, amorphous structure with little strength. It can be easily hydrolyzed by dilute acid or base and as well as by myriad hemicellulose enzymes. Hemicellulose is bio-degradable and degraded through synergistic action of few enzymes of some bacteria and fungi. It has a lower molecular weight compared to cellulose.

Applications:

Cellulose: A large quantities of cellulose is mainly used to produce paperboard and paper. Smaller quantities are converted into a wide variety of derivative products such as cellophane and rayon. The conversion of cellulose into biofuels such as cellulosic ethanol is at the research stage to use as an alternative fuel source. Wood pulp and cotton are the main cellulose sources for industrial applications.

Hemicellulose: It is used as films and gels in packaging. Since, hemicellulose is non-toxic and bio-degradable it is used in edible films for coating food stuff to maintain the texture, taste and the mouth feel. And also, it is used as a dietary fiber.

Definitions:

Synergistic action: An effect arising between two or more agents, entities, factors, or substances that produces an effect greater than the sum of their individual effects.

 Image Courtesy:

“Cellulose Sessel” By NEUROtiker – Own work (Public Domain) via Commons Wikimedia

“Hemicellulose” By BerserkerBen – Own work (Public Domain) via Commons Wikimedia