EVERYDAY SCIENCE

Detailed explanation-1: -The most characteristic component found in all plant cell walls is cellulose. It consists of a collection of -1, 4-linked glucan chains that interact with each other via hydrogen bonds to form a crystalline microfibril (Somerville, 2006).

Detailed explanation-2: -The cellulose molecules provide tensile strength to the primary cell wall.

Detailed explanation-3: -Primary and secondary walls contain cellulose, hemicellulose and pectin, albeit in different proportions. Approximately equal amounts of pectin and hemicellulose are present in dicot primary walls whereas hemicellulose is more abundant in grasses (e.g., switchgrass).

Detailed explanation-4: -Cellulose is the most abundant biopolymer, as it comprises the major structural component of the cell walls of lower and higher plants. We find high cellulose contents in stalks and stems and in other woody parts of plants.

Detailed explanation-5: -Secondary cell walls are primarily composed of cellulose, hemicelluloses (xylan and glucomannan) and lignin (Fig. 1j), with a minor amount of structural proteins and enzymes.