Amylose: Structure, Physical Characteristics, Properties, Uses

Amylose

Amylose is a type of carbohydrate – more specifically, it is a linear polysaccharide made up of repeated units of α-D-glucose linked together by α$(1 \rightarrow 4)$glycosidic bonds. As a biomaterial, amylose is utilised in many different sectors. In nature, it is a polysaccharide. The linear component amylose is composed of 100 to 10,000 glucose monomers that are all connected by 1, alpha binding. Although amylose is a type of sugar, it differs greatly from the natural starch found in maize. This features a dispersed polymer structure with about 6000 glucose deposits distributed into branches of one every 24 glucose rings.

A parallel double-helix of linear glucose chains makes up amylose A.

Molecules of glucose that have been $(1 \rightarrow 4)$ bonded make up amylose. Beginning with the aldehyde (C=O) carbon, the carbon atoms in glucose are numbered. As a result, in amylose, the 1-carbon on one glucose molecule is linked to the 4-carbon on the next glucose molecule by $(1 \rightarrow 4)$ bonds. The image on the right shows the amylose structural formula. The number (n) of repeating glucose subunits is typically in the 300–3000 range, but it can be much higher.

Amylose chains can assume one of three primary shapes. It can take on two distinct helical configurations or a disordered amorphous shape. It can associate with another hydrophobic guest molecule, like iodine, a fatty acid, or an aromatic component, or it can associate with itself in a double helix. In the structure of starch, amylopectin binds to amylose in what is referred to as the V form. There are numerous diverse varieties within this category. Each is noted with a V, followed by a subscript that lists the number of glucose units consumed throughout each turn. The V6 variant, which has six glucose units each turn, is the most popular. There are other V8 and maybe V7 variants.

Structure Of Amylose

Physical Characteristics Of Amylose

• Amylase emits a distinctive, disagreeable smell.

• It takes the form of white crystals.

• Amylose has a density of 1.25 g/mL.

• Water does not dissolve amylose.

• At 760 mmHg, it has a boiling point of 627.7 55.0 °C.

• There is a variable molecular weight in amylose.

• The chemical formula for this substance is $\left(\mathrm{C}_6 \mathrm{H}_{10} \mathrm{O}_5\right)_{\mathrm{n}}$.

• The amylose compound has a surface tension of 74.4 5.0 dyne/cm.

• It consists of the glycoside's bonds.

• Close connections that assemble these particles are probably made up of amylose particles.

• Iodine and amylose interact to produce a bluish-black colour.

• Amylose has an unpleasant scent.

• White crystals make up the amylose structure.

Chemical Properties Of Amylose

• The chemical formula for amylose is $\left(\mathrm{C}_6 \mathrm{H}_{10} \mathrm{O}_5\right)_{\mathrm{n}}$

• Iodine and amylose combine to produce a characteristic blue colour complex.

• High-performance size exclusion chromatography and other techniques are used to deliver the analysis.

• Amylose molecules have the potential to create strong hydrogen bonds, which makes them resistant to enzyme breakdown.

Uses of Amylose $\left(\mathrm{C}_6 \mathrm{H}_{10} \mathrm{O}_5\right)_{\mathrm{n}}$

• Permanent textile finishes, plastics, film production, and paper pulp fibre bonding are a few applications for amylose.

• For a crisp coating that also helps to limit oil absorption, high amylose starches have been combined with an instant starch or food gum as a binder.

• Incorporated into pasta and bread crusts for more even heating in the microwave. Used as starches in sausage casings and food wrappers.

Also Read

• Proteins
• Enzymes
• Vitamins

Function Of Amylose $\left(\mathrm{C}_6 \mathrm{H}_{10} \mathrm{O}_5\right)_{\mathrm{n}}$

Amylase has a very predictable impact on how much energy plants store. Since amylase has a helical structure and takes up less space than amylopectin does, it is not very easily digested when it is converted to amylopectin. At least 30% of the stored starch in all plants is accounted for by amylase.

The enzyme amylase breaks down starch into maltose and maltotriose, which provide energy to plants.

Benefits Of Amylose For Health

There are various health advantages of amylose, including

• Acts as a prebiotic: The non-digestible substance bypasses digestion and enters the colon. In the intestines, microbes ferment it. Prebiotic amylose supports healthy gut flora, has a positive effect on internal body systems, and improves health.

• Increases Immunity: Beneficial gut bacteria also increase immunity. As a result, amylose's prebiotic action increases immunity.

• Helps Prevent Obesity and Lose Weight: The benefits of amylose for weight loss are still up for debate; however, there is some supporting data. According to studies on animals, consuming amylose leads to a considerable decrease in fat tissue.

• Decreased risk factors for heart disease: Improves heart health and decreases heart disease.

Some Solved Examples

Question 1: Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Amylose is insoluble in water.
Reason R: Amylose is a long linear molecule with more than 200 glucose units. In light of the above statements, choose the correct answer from the options given below.

1) Both A and R are correct, and R is the correct explanation of A.

2) Both A and R are correct, but R is NOT the correct explanation of A.

3) A is correct, but R is not correct.

4) (correct) A is not correct, but R is correct.

Solution:

Starch consists of two types of polysaccharide molecules, Amylose and Amylopectin. Amylose is soluble in water, but not Amylopectin. Amylose is a linear polymer consisting of 06 out of 200 units.
Hence, the answer is option (4).

Question 2: Animal starch is another name of

1)amylose.
2)maltose.
3) (correct) glycogen.
4)amylopectin.

Solution:

Disaccharides
The disaccharides consist of two molecules of monosaccharides. When hydrolysed with enzymes or dilute acids, they give two molecules of either the same or varying monosaccharides. Some examples include,

$\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11} \xrightarrow{\mathrm{H}_2 \mathrm{O}} \mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6+\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6$
Sucrose Glucose Fructose

$\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11} \xrightarrow{\mathrm{H}_2 \mathrm{O}} \mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6+\mathrm{C}_6 \mathrm{H}_{12} \mathrm{O}_6$
Lactose Glucose Galactose

Based on the position of linkages between the two monosaccharide units, the disaccharides might be reducing or non-reducing in nature. The resultant disaccharide is non-reducing if the glycosidic linkage involves the carbonyl functions of both monosaccharide units. On the other hand, the resulting disaccharide is the reducing sugar, e.g., maltose and lactose, if one of the carbonyl functions in either of the monosaccharide units is free.

Polysaccharides
Polysaccharides are carbohydrates having hundreds or even thousands of monosaccharide units joined together by glycosidic linkages, e.g., starch, cellulose, glycogen and dextrins. However, starch and cellulose are the most important polysaccharides.

The carbohydrates are stored in the animal body as glycogen. It is also known as animal starch.

Hence, the answer is option (3).

Question 3: Glycosidic linkage between C 1 of a-glucose and C 2 of $\beta$-fructose is found in

1) Maltose

2) Surcose (Correct)

3) Lactose

4) Amylose

Solution:

The glycosidic linkage between Cl of $\alpha-$ glucose and $\mathrm{C}_2$ of $\beta-$ fructose is found in sucrose.

Hence, the answer is option (2).

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