Notes on The cell wall, Primary, Secondary, tertiary cell wall, Middle lamella 11-12 class

Cell wall:

cell wall

The cell wall is complex in nature and is differentiated in the following layers: cell wall 

Primary cell wall:

The first farmed cell wall is known as primary cell wall.

It is an outermost layer of the cell and in the immature meristematic and parenchymatous cells it form the only cell wall.

The primary cell wall is comparatively thin and permeable.

Certain epidermal cells of the leaf and the stem also possess the cutin and cutin waxes which make the primary cell wall impermeable.

The primary cell wall of the yeast and the fungi is composed of the chitin.

Secondary cell wall:

The primary cell wall is followed by a secondary cell wall,

The secondary cell the wall is thick, permeable, and lies near the plasma membrane of the tertiary cell wall, if the latter occurs.

It is composed of the three concentric layers(S₁, S_2, and S₃)which occur one after another.

Chemically the secondary cell wall is composed of compactly arranged microtubules of the cellular, in between which sometimes occurs lignin as an interfibrillar material.

Tertiary cell wall:

In certain plant cells, there occurs another cell wall beneath the secondary cell wall which is known as the tertiary cell wall.

The tertiary cell wall differs from the primary and secondary cell wall in its morphology, chemistry, and staining properties.

Besides the cellulose, the tertiary cell wall consists of another chemical substance known as the Xylan

Middle lamella:

The cell of a plant tissue generally remain cemented together by an intercellular matrix is known as the middle lamella.

The middle lamella is mainly composed of the Pectin, Lignin, and some Proteins.