Question

The cell wall of prokaryotes are made up of
(a) Cellulose
(b) Proteins
(c) Peptidoglycan
(d) Protein and fats

Answer 1

Hint: Prokaryotic cell wall is made up of polymer amino acids & sugar.

Complete answer: Prokaryotes are single celled organisms and their cells are much smaller than cells of eukaryotes. Prokaryotes lack nucleus and cell organelles.

These cells are enclosed by a rigid cell wall. The cell wall is made up of a large polymer of some amino acids and carbohydrates. The polymer is known as peptidoglycan. It is made up of glycan (disaccharide) chains of repeating N-acetylglucosamine(NAG) and N-acetylmuramic acid (NAM) residues.

These residues are cross-linked by peptide side chains. The peptides contain some D-amino acids along with the regular L-amino acids. This feature makes the peptidoglycan unique. There is a high level of diversity in the peptide sequences or the amino acids in different species of prokaryotic organisms.
Peptidoglycan is commonly called ‘murein’. It provides a stiff structure that gives the cell its shape and surrounds the cytoplasmic membrane. The cell wall is located below the capsule of the organism.
If the organism is a pathogen, its peptide (which becomes an antigenic peptide) can elicit immune response in the infected person.
Cellulose is a component of plant cell wall and proteins like chitin are constituent of fungi cell wall.

So, the correct option is C. Peptidoglycan.

Note:The cross linking between NAG and NAM provides the peptidoglycan its rigidity or stiffness. The stiffness protects the prokaryotic cell from physical abrasion.