Amylose and Amylopectin, the stored carbohydrates in plants, are the most confusing terms in biology, particularly for those with slight acquaintances with starch formation. Starch, a colourless and odourless polysaccharide, is found in plants in the form of carbohydrates. The intertwined polymers of glucose monomers form polysaccharides which lead to the formation of starch in plants. The freshmen attending the first sessions of their biology lectures might not be aware of starch formation and how amylose and amylopectin are linked to the process.
Apart from defining the terms amylose and amylopectin in detail, we will also spell out the key differences and similarities between the two significant components of starch, i.e. amylose and amylopectin. All biology fellows, catch a glance at the post below to grow your understanding of two of the most confusing terms of biology.
What Is Amylopectin?
Amylopectin is a highly branched polymer made up of glucose units in plants. Multiple glucose units make the formation of the branched polymer, and it refers to be a polysaccharide. The principal physical character of amylopectin is that it is water-soluble. It can be hydrolysed into several glucose units with α-amylase and β-amylase enzymes. Amylopectin is vital for plant’s sustenance as they act as a significant source of energy for plants.
Short grain rice, Jasmine rice, and a few strains of potatoes are rich in amylopectin. When humans and other animals consume amylopectin-rich foods, the enzyme amylase helps amylopectin get digested. It is surprising to know that foods like rice and grains have 99 to 100 per cent amylopectin content.
Use of Amylopectin
Apart from being the principal energy source for humans and animals, amylopectin also holds the properties for industrial use. It is used for starch retrogradation and proper binding of gel-based items such as adhesives and lubricants.
Structure Of Amylopectin
The chemical formula of amylopectin, which is [C6H10O5]n, is derived from its properties where glycosidic bonds link a series of glucose units. Two linked monosaccharides make a glycosidic bond – this makes the fundamental formation of amylopectin as a polysaccharide. The length of the amylopectin chain has 20 to 30 glucose units, and it defines the whole structure of amylopectin. The structure of amylopectin can vary in size depending on the length of the plant branch and may go from 2,000 glucose units to as much as 200,000 units. The presence of six glucose units at every turn of the branch makes the structure of amylopectin; and, this is why the structure of amylopectin is said to be branched.
What Is Amylose?
Amylose is defined as the linear polymer of glucose units. Potentiometric titration is the process that determines the amount of amylose present in starch. Those, who have not heard about the term potentiometric titration before, need to know that it is nothing but the strength between Iodine and Amylose. Wheat starches and potatoes contain around 19.9% of iodine affinity, while starch present in maise holds approximately 19.0%. Amylose is the best choice for ligand, and the reason why Amylose is preferred for ligand is its feasibility of coupling with the native matrix.
Use Of Amylose
Since amylose consists of linear polymers of D-glucose units, they are preferred for various industrial purposes. Their property of making string hydrogen bonds make them less vulnerable to enzymatic degradation. The character of the strong bond between molecules in amylose makes them usable material for so many products. From permanent textile finishes to manufacturing paper pulp fibre and plastic bonding to filmmaking, amylose has great use in different industries. The crisp coating that you see in French fries makes use of the solid binding character of amylose. Several other foods have a significant share of application in the making process.
Structure of Amylose
If you are aware of the formation of glucose units, it will not be much hard for you to understand the formation process of amylose structure. All subunits of oxygen atoms, CH2OH molecules, and carbon atoms collectively form the glucose molecule. The glycosidic bonds help the glucose molecules link together. The structure formation of glucose leads to the formation of amylose, giving the real cue about the structure of amylose.
Key Differences Between Amylose & Amylopectin
You can add keywords here in one line.
| Amylose | Amylopectin |
| It is made up of linear polymer of D-glucose units; | Amylopectin is a chain polymer of D-glucose units; |
| Starch composition is only 20% in amylose; | Starch composition in amylose is approximately 80%; |
| While amylose can slightly dissolve in water | Amylopectin is completely soluble in water; |
| It has a straight-chain structure; | It has a branched-chain structure; |
| It turns blue when combined with Iodine; | It shows a reddish-brown when combined with iodine; |
| There is no swelling observed when dissolved in hot water; | It gets dissolved in hot water, showing swelling; |
| Gel formation is seen with the addition of hot water | No gel is formed. |
Similarities Between Amylose and Amylopectin
Despite the differences between amylose and amylopectin, there are some similarities as well. The common properties which both amylose and amylopectin share are:
- Both are polysaccharide molecules;
- Both are composed of D-glucose units;
- Both molecules have α 1-4 glycosidic linkages
- Both have starch granules.
Functional Perspectives Of Amylose And Amylopectin
The primary function of Amylose is that it acts as a food reserve and a source of energy. Since it can work as a thickening agent, it is used as an emulsion stabiliser gel-based food content. The tightly packed structure makes it an effective prebiotic substance and suitable for industrial use for water-based binding content. Amylose is easily digestible as compared to amylopectin.
Amylopectin structure is formed of 20–24 glucose subunits. Since it easily gets dissolved in water, it has a lower tendency of retrogradation (gelling). For this main reason, in different applications, mainly as a stabiliser.
Final Thought
Amylose and amylopectin are the two important types of polysaccharides of starch granules. However, they have structural differences and similarities. Hopefully, the above guide gives you a clear idea.
