What is the Difference Between Amylose and Cellulose?

Amylose and cellulose are both linear polymers of glucose, but they have different structural characteristics and functions. The main differences between amylose and cellulose are:

1. Glycosidic Bonds: Amylose has α-(1–4) glycosidic bonds, whereas cellulose has β-(1–4) glycosidic bonds.
2. Structural Organization: Cellulose forms long linear chains, while amylose organizes into three-dimensional helical structures.
3. Digestibility: Humans can digest amylose, but not cellulose.
4. Orientations of Glucose Molecules: In cellulose, glucose molecules are found in an alternative pattern where one is down and one is up, but in amylose, glucose molecules are in the same orientation.
5. Function: Amylose is an energy storage compound in plants, making up 20-30% of the structure of starch. Cellulose is mainly a structural compound, participating in cell wall formation in plants, providing strength and rigidity to plant cells.
6. Solubility: Amylose is insoluble in water, and it reduces the crystallinity of amylopectin.
7. Interaction with Iodine: In the iodine test for starch, the iodine molecules fit into the helical structure of amylose, giving a dark purple/blue color.

In summary, amylose and cellulose are both linear polymers of glucose, but they have different glycosidic bonds, structural organizations, digestibility, orientations of glucose molecules, functions, and interactions with iodine.

Comparative Table: Amylose vs Cellulose

The main differences between amylose and cellulose are their chemical structure, function, and digestibility. Here is a comparison table highlighting these differences:

In summary, amylose is a linear storage polysaccharide made of α-D-glucose units, while cellulose is a structural polysaccharide made of β-D-glucose units. Amylose serves as an energy storage compound in plants, whereas cellulose is a major component of plant cell walls. Humans can digest amylose but not cellulose.