Question

What is middle lamella?

Answer 1

Hint: The middle lamella works between the primary walls of adjacent cells as a cementing layer. It consists of pectin that acts as a glue.

Complete answer:
To answer this question, first, we need to know about the cell wall of the plant cell. The cell wall of plant cells is a dense layer composed of cellulose, glycoproteins, lignin, pectin, and hemicellulose. This lies outside the membrane of the cells. It contains proteins, cellulose, and polysaccharides. The cell wall's primary function is to protect the cell and provide structural support. The plant cell wall also works to protect the cell from mechanical stress and to provide the cell with shape and structure. It also filters molecules that pass through and out of the cell. Microtubules guide the formation of the cell wall. This is composed of three layers, primary, secondary, and middle lamella. The primary cell wall is constructed by cellulose which is laid down by enzymes.
Now, let us define the given term-
The middle lamella is a membrane that cements together the cell walls of two adjacent plant cells. This is the first layer formed which is deposited during cytokinesis. The cell plate shaping itself during cell division forms into middle lamella. The middle lamella consists of pectin which serves as a gelling agent or glue which keeps together the plant. The role of the middle lamella, in simple terms, is the adherence of adjacent cells. It contains pectates of calcium and magnesium. It forms the outermost layer of the cell wall in a mature plant cell.

Note: The plant cell wall contains two layers and they are primary cell wall and middle lamella. The secondary wall is the additional layer that is produced by many cells.