Question

What is the function of a cell wall?

Answer 1

Hint: The cell wall is a feature of many eukaryotic and prokaryotic cells. In a prokaryotic cell, it is present along with other components together as a cell envelope. The structure of the cell wall is different in prokaryotic cells and eukaryotic cells.

Complete answer: In a prokaryotic cell, a cell wall is present between the outermost glycocalyx and plasma membrane which is seen on the inner side. The functions of the cell wall in prokaryotes include maintaining the shape and structure of the cell and also protecting the cell from mechanical injuries. These functions are almost similar to that of the eukaryotic cell wall. The eukaryotic cell wall helps in resisting infections and also prevents damage to the cell. Keep in mind that the cell wall is a barrier to the undesirable molecules as they prevent the entry of these molecules to the cells. The composition of the cell wall is also different in different organisms. The bacterial cell wall is made up of complex polysaccharides called peptidoglycans. The peptidoglycan content is more in gram-positive bacteria and they also contain more teichoic acid. Meanwhile, gram-negative bacteria have lesser peptidoglycans in their cell wall and have a lipid layer on the outside which is made up of lipopolysaccharides. In algae, the cell wall is made up of cellulose, galactans, mannans, and certain minerals like calcium carbonate. In higher plants, the cell wall contains cellulose, hemicellulose, pectins, and proteins.

Note: In plants, there are two types of cell wall. They are primary and secondary cell walls. Among these, the primary cell wall is capable of growth and gets faded when the plant cell undergoes growth and maturation and is replaced by the secondary cell wall.