Cell Wall Structure

Questions and Answers

To cement the walls of neighboring cells together (correct)

To allow for cell expansion

To provide rigidity to the cell

To serve as a protective barrier against pathogens

It is formed after the middle lamella.

It is more elastic and extendable than the secondary wall. (correct)

It is composed primarily of lignin.

It is typically thicker than the secondary wall.

It is primarily made of lignin and mineral salts. (correct)

It is usually about 1 - 3μm thick.

It is laid down outside the primary wall.

It is mainly composed of cellulose and pectic compounds.

Cellulose, hemicellulose, and pectic compounds Signup and view all the answers

Facilitating nutrient absorption Signup and view all the answers

Secondary wall Signup and view all the answers

Study Notes

The cell wall consists of three fundamental parts: middle lamella, primary wall, and secondary wall.

The primary wall is the first wall formed in a developing cell.
It is usually 1-3μm in thickness.
It is more or less elastic and extendable, crystalline, and optically active.
The primary wall is composed of cellulose, pectic compounds (mostly polysaccharides), and hemicellulose.

The secondary wall develops after the primary wall.
It is laid down inside the primary wall.
The secondary wall is about 5-10μm in thickness, more or less rigid, crystalline, and strongly optically active.
It is mainly composed of lignin, cellulose, non-cellulosic polysaccharides, hemicelluloses, and mineral salts of Ca, Mg, K, and some silica.

The cell wall forms a framework for the cell to prevent over-expansion.
Cellulose fibers, structural proteins, and other polysaccharides help maintain the shape and form of the cell.