What is Amylose Definition Structure Formation and Uses
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.
FAQs on Amylose Structure Properties and Biological Role
1. What is amylose?
Amylose is a linear polysaccharide made of α-D-glucose units linked by α(1→4) glycosidic bonds. It is one of the two main components of starch, the other being amylopectin. Amylose typically forms helical structures and has the general formula (C6H10O5)n, where n represents the number of glucose units.
2. What is the chemical formula of amylose?
The chemical formula of amylose is (C6H10O5)n. Each repeating unit comes from a glucose molecule (C6H12O6) after the loss of one water molecule during condensation polymerization.
- Monomer: α-D-glucose
- Linkage: α(1→4) glycosidic bond
- Polymer type: carbohydrate (polysaccharide)
3. What is the difference between amylose and amylopectin?
The main difference between amylose and amylopectin is that amylose is linear, while amylopectin is highly branched.
- Amylose: α(1→4) glycosidic bonds only; mostly unbranched.
- Amylopectin: α(1→4) chains with α(1→6) branch points.
- Amylose forms helical structures; amylopectin forms a tree-like structure.
4. How is amylose formed from glucose?
Amylose is formed by condensation polymerization of α-D-glucose units through α(1→4) glycosidic bonds. During each linkage:
- The –OH group of carbon 1 of one glucose reacts with the –OH group of carbon 4 of another.
- One molecule of water (H2O) is eliminated.
5. Why does amylose give a blue color with iodine?
Amylose gives a blue color with iodine because iodine molecules fit inside its helical structure, forming a charge-transfer complex.
- The iodine (I2) molecules align within the amylose helix.
- This interaction produces a deep blue complex.
- The reaction is commonly used as a test for starch.
6. Is amylose soluble in water?
Amylose is only slightly soluble in cold water but becomes more soluble in hot water.
- In cold water, strong hydrogen bonding limits solubility.
- Heating disrupts intermolecular hydrogen bonds.
- It forms a colloidal dispersion rather than a true solution.
7. What type of glycosidic bond is present in amylose?
Amylose contains α(1→4) glycosidic bonds between glucose units.
- The bond forms between carbon 1 of one α-D-glucose and carbon 4 of the next.
- The α-configuration causes the chain to coil into a helix.
- No α(1→6) branching bonds are present in pure amylose.
8. How does amylose differ from cellulose?
Amylose differs from cellulose in the type of glycosidic bond and overall structure.
- Amylose: α(1→4) bonds; helical structure; digestible by humans.
- Cellulose: β(1→4) bonds; straight chains; forms strong fibers; indigestible to humans.
9. What is the role of amylose in starch?
Amylose acts as the linear component of starch and contributes to its thickening and gel-forming properties.
- Starch typically contains 20–30% amylose.
- It influences gelatinization and retrogradation.
- Higher amylose content increases gel firmness.
10. What happens when amylose is hydrolyzed?
When amylose is hydrolyzed, its α(1→4) glycosidic bonds are broken to form smaller sugars such as maltose and glucose.
- Hydrolysis can be acid-catalyzed or enzyme-catalyzed (e.g., amylase).
- Complete hydrolysis produces glucose (C6H12O6).
- This process is important in digestion and industrial fermentation.
