The difference between starch and cellulose is a very important topic for identifying their important characteristics. Both of these compounds are important polysaccharides in nature that perform a variety of functions. Polysaccharides are larger-sized polymers made up of 10 to thousands of monosaccharides, linked by glycosidic linkages.
What is starch?
Starch is a complex polysaccharide found in nature made up of the chain of amylose and amylopectin. The repeating units of glucose monomers in this compound are connected by alpha bonds directed in one direction. This compound is less crystalline and is weaker than cellulose. This compound is not soluble in cold water but dissolved in warm water.
It is very much found in grains like potatoes, rice, cereals, bread, and many other food items. It maintains health benefits like it lowers our increased insulin level or glucose level and is used as a source of energy and a metabolism aid when reaching our bodies. This important compound is used as a thickening agent in baking cakes and pastries, a binding agent in soups and sauces, a bulking agent in dairy items, glue, for tightening up clothes and weaving linen, for thickening sauces and for paper treatment and a sweetening agent in beverages.
Types of starch
There are mainly two types of starch namely amylose and amylopectin. It is generally found 10%–30% amylase and 70%–90% amylopectin in the natural source.
What is cellulose?
Cellulose is a very common natural organic compound but a complex carbohydrate that is made up of 100 or 1000s of glucose units. This compound is generally found in plant walls and is considered as the fundamental component of plant cells. This complex polysaccharide cannot be digested by humans. This compound is not soluble in water. Animals can digest cellulose by having some enzymes that can break down cellulose into glucose.
Cellulose has various commercial uses and is the main constituent of the paper. The cellulosic fiber is used to make clothes such as linen and cotton. This compound is also used to make cellophane and rayon.
Structure of starch
The starch compound is constructed from monomers of the α-glucose chain. That chain contains the glycosidic bonds which are formed through the reaction of condensation. Glycosidic linkage is formed between the first carbon of one glucose monomer and the fourth carbon of the second glucose monomeric unit by the process of polymerization. Water molecule is released after this reaction. This organic polymeric molecule consists of two types of complex polysaccharides namely amylose and amylopectin. This necessary compound is made up of sugar glucose. We know that glucose molecule contains carbon (C), hydrogen (H), and oxygen (O). The formula of the glucose molecule is C6H12O6.
Structure of cellulose
This important compound has no taste, and no odor, and is a chiral compound that was discovered by French Chemist AnselmePayen in the year 1838. The glucose monomer in this compound is rotated 180 degrees around the polymer backbone chain’s axis and cellulose structure is obtained. It is made up of hundreds to thousands of d-glucose monosaccharide units, linked together with a β-(1,4) linkage to form a chain. This compound turns into a glucose molecule after treatment with concentrated mineral acids at high temperatures. The d-glucose units in this compound are attached to each other via beta 1-4 glycosidic bonds known as beta-acetal connection.
Types of cellulose
There are four types of cellulose namely cellulose I, II, III, and IV. Among these, cellulose I is the native structure of cellulose which is very much in nature and can be found primarily in the plant cell wall. This important compound decomposes at 300°C–400°C. It is an unbranched, strong, and linear type molecule made up of β-1,4-linked d-glucose polysaccharide units containing crystalline and amorphous regions.
Structural Difference between Starch and Cellulose
Amylose and amylopectin are the two main ingredients to construct starch. Whereas, amylose is a long linear chain of -D-(+)-glucose units connected by glycosidic linkage of C1 to C4 (along-link). Amylopectin is a complex branched-chain polymer formed by D-glucose units in which the chain is constructed by glycosidic connection C1 to C4 and glycosidic connection C1 to C6 branches.
Cellulose is a straight-chain complex polysaccharide made up of β – D-glucose units joined by glycosidic linkage C1 to C4 (β-link).
Starch vs Cellulose Basic
Starch is made up of 100-1000s of d-glucose monosaccharide units, linked together with a β-(1,4) linkage to form a chain. On the other hand, Cellulose is a straight-chain polysaccharide made up of β – D-glucose units bonded by glycosidic linkage C1 to C4 (β-link). Starch is found in most of plants and is the main type of carbohydrate storage in plants, whereas cellulose is found in the cell walls of plants and is the main type of structural component in plants.
Difference between Starch and Cellulose
There are various factors on which starch and cellulose can be differentiated easily. They are given below:
Definition
Background
Types of glucose
Glucose range
Forms
Bonding
Availability
Solubility
Strength
Crystallinity
Consumption
Uses
Forms
Found in
Molar mass
Now, let’s discuss about the difference between starch and cellulose on the basis of these factors individually.
On the basis of definition
Starch is a type of complex polysaccharide that is plants’ primary energy storage molecule that is composed of glucose units.
Cellulose is a complex polysaccharide that contains a linear chain of glucose molecules linked by beta-glycosidic linkage.
On the basis of background
Starch is generally found in green plants, whereas cellulose is found in in the cell walls of plants and bacteria.
On the basis of glucose range
About 200-1000 glucose molecules take part to make a starch molecule, whereas 500 glucose molecules take part to make one molecule of cellulose
On the basis of Component
Starch is considered the one kind of carbohydrate, whereas cellulose is one kind of fiber. The component of starch includes amylose and amylopectin while the component of cellulose is beta-glucan.
On the basis of function
Starch is considered the main carbohydrate storage in plants and acts as an energy reserve.
Cellulose is one kind of structural component that provides support and strength to plants.
On the basis of glucose unit linkages
Starch contains alpha glucose unit linkages, whereas cellulose consists of beta glucose unit linkages
On the basis of molar mass
Starch contains a lower mass and cellulose contains a higher molar mass.
On the basis of availability
Starch is found in our nature more than cellulose.
On the basis of bonding role
Starch stores energy in plants, whereas cellulose provides strength and rigidity to the cell walls of plants.
On the basis of the type of chain
Starch is considered as a long and branched molecule, whereas cellulose is a straight-chain polymer.
On the basis of solubility in water
Starch does not show solubility, whereas cellulose is soluble in water.
On the basis of forms
Starch exists in three forms – amylose, amylopectin, and cyclodextrin, whereas cellulose molecules can exist in two forms namely crystalline and amorphous.
Starch vs Cellulose
Definition
Starch is a complex polysaccharide consisting of a large number of glucose monomers joined together by glycosidic linkages.
Cellulose is a complex polysaccharide consisting of a large number of oxygen, carbon, and hydrogen-linked D-glucose units.
Connection
Starch contains alpha linkage.
Cellulose contains beta linkage.
Crystallinity
Starch contains less crystallinity.
Cellulose contains high crystallinity.
Strength
Starch has higher strength.
Cellulose has weaker strength.
Solubility
Starch dissolves in warm water.
Cellulose does not dissolve in water.
Forms
Starch shows grain form
Cellulose shows fiber form.
Found in
Starch is found in plants.
Cellulose is found in plant cell walls.
Molar mass
Starch has a higher molar mass.
Cellulose has a lower molar mass.
Starch and Cellulose in Class 11
The matter of cellulose-related information is well explained in Class 11 textbooks. There is a nice diagrammatic presentation of a portion of glycogen to explain the cellulose. The cellulose is described there as a polymeric polysaccharide molecule. Similarly, starch is also narrated with its molecular structure matter.
Starch and Cellulose in Class 12
The starch and cellulose are explained in more detail in class 12 books with their properties and structural differences. In class 12 textbooks, the structural difference between cellulose and starch is described clearly with the structure of glucose monomer units.
