Dhristi JEE 2022-24

What are Amylose and Amylopectin?

Amylose is used in numerous industries as a biomaterial. It is a polysaccharide in nature. Amylose is a linear component and it is made up of between 100-10,000 glucose monomers and these are all linked by 1, alpha bindings. An amylose is a form of sugar, however, it has very different properties from native maize starch. The structure of this is a spread polymer that has around 6000 glucose deposits separated into branches of 1 in each 24 glucose rings. 


What are the Chemical Properties of Amylose?

  • The IUPAC name of this compound is (1→4)-α-D-Glucopyranan.

  • Amylase has a density of 1.25 g/mL

  • It is insoluble in water 

  • The boiling point of Amylose is 627.7 ± 55.0 °C at 760 mmHg.

  • It has a variable molecular mass

  • The chemical formula for this compound is (C6H10O5)n

  • It also has a surface tension of 74.4 ± 5.0 dyne/cm

  • It forms α glycosidic bonds

  • When exposed to hydrogen amylase molecules tend to form very tight bonds which make these molecules less prone to enzymatic degradation. 

  • When it reacts with iodine, it forms a very distinct blue-colored compound. 


What are the Physical Properties of Amylose?

  • Amylase has a characteristic unpleasant odor

  • It is formed in white crystals

  • The surface tension of Amylose is 74.4±5.0 dyne/cm. 


Uses of Amylose (C6H10O5)n

Now let us take a look at what is amylose used for. Its uses are described as follows.

  • Amylose is used in the permanent textile finishes, film making, plastics, and bonding of paper pulp fiber.

  • Higher amylose starches are used together along with food gum or instant starch as a binder which helps in providing a crisp coating while making french fries which, in turn, also reduces the oil absorption.

  • It is also used as starches for food wrappers and sausage casings, incorporation into pasta and bread crusts for even heating in the microwave.


The Function of Amylose (C6H10O5)n

Let us now discuss what is the function of amylose.


Amylase plays a very deterministic role in the energy that is stored by plants. When it is converted to amylopectin, it is not digested very easily, since amylase has a helical shape that takes up less space as compared to the space taken up by amylopectin. Amylase accounts for at least 30 percent of the starch that is stored in all plants. 


Amylase enzyme α-amylase breaks it down further into maltose and maltotriose, and these give energy to the plants.

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FAQs (Frequently Asked Questions)

1. What is the difference between amylase and amylopectin?

Both amylose and amylopectin are two kinds of polysaccharides that are found in plants. They are very similar in their structure and in their chemical composition as well. The main point of distinction between them is that amylase is a straight-chain polymer, while amylopectin is made of branched chains. Molecules in amylase are bonded with 1,4 alpha bonds, while in amylopectin, molecules are bonded with both 1,4 and 1,6 alpha bonds. Amylose and amylopectin can both be digested and broken down to produce energy.

2. Is amylase the same as amylose?

No, these are different compounds. Amylase is an enzyme that turns starch into sugar. Amylase is found in the saliva of humans and animals and it is very useful in the process of digestion. In comparison, amylose is found only in plants and it is not an enzyme, but a polysaccharide. It cannot be produced in human beings since it is consistently the main form of starch that is present in plants. While plants can also produce amylase, humans and other animals cannot produce amylase.

3. How is amylose digested?

In plants, amylose constitutes a distinct portion of the starch reserves. These are stored by plants for supplying them with energy. Starch is converted into simple glucose in plants through a number of consecutive processes. The compounds Amylose and amylopectin are both hydrolyzed into very small components so that they are easier to break down. This is facilitated by the presence of alpha-amylase which is an enzyme that helps in breaking down complex sugars into simple glucose for energy conversion.

4. Which is more suitable for digestion, amylose or amylopectin?

In theory, amylose should be easier for digestion since it does not need to be accompanied by isomaltase and due to it having straight bonds, it also does not have the steric hindrance properties that are caused by branched chains. This is not true, since amylose has a very complicated structure which although should be easier to digest in chemical terms, does not happen in reality. The structure of amylose is not suited for direct digestion. This means that amylopectin is more readily digestible than amylose.

5. Why is it that the human body cannot digest cellulose?

Cellulose is formed in plants and consists of starch that is issued for energy conversion. However, in human beings, this passes undigested through bowels and cannot be broken down. This is because the human body does not have the right enzymes to disintegrate the beta acetal links that are required to break down and use cellulose for energy. The human digestive system lacks the ability to be able to break down monosaccharide bonds that are present in cellulose, and thus, cellulose passes through the bowels undigested.

6. What is Amylase?

Amylase is an enzyme that tends to catalyze the hydrolysis of starch into sugars. Amylase is a constituent in the saliva of humans and many other mammals, which tends to begin the chemical process of digestion. Foods that contain higher amounts of starch but a little sugar, for example, rice and potatoes, might have a slightly sweet taste as we chew them since amylase tends to degrade some of the starch into sugar. The pancreas and salivary glands in our body make alpha-amylase to hydrolyze dietary starch and then into disaccharides and trisaccharides. These are then converted by several other enzymes into glucose for supplying our body with energy. Plants and some of the bacteria also tend to produce amylase.

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