Question

Diaminopimelic acid and muramic acid occur in the wall of
a. Bacteria
b. Fungi
c. Brown algae
d. Higher plants

Answer 1

Hint: The wall made up of Diaminopimelic acid and muramic acid consists of amino acid, and sugars that form a net-like structure outside the plasma membrane which forms the cell wall. The living organisms which contain cell walls are plants, prokaryotes, algae, fungi, etc.

Complete answer:
A cell wall is a structure that provides support, protection, and filtering mechanism. Let’s go through the options to find out the correct answer.
- The cell wall of bacteria composed of peptidoglycan. Peptidoglycan contains polysaccharide stands of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). Some bacteria contain diaminopimelic acid with muramic acid.
- The cell wall of fungi contains chitins, glucans, glycoproteins, and pigments.
- The cell wall of brown algae composed of fucose containing sulfated polysaccharides.
- Plant’s cell wall is composed of cellulose.

Hence, the correct answer is option (A).

Additional information:
Diaminopimelic acid (DAP) is a derivative of lysine amino acid. DAP is linked with NAM-NAG chains in the cell wall of gram negative bacteria. One peptide chain is linked through a peptide bond with other peptide chains. In sufficient amounts they exhibit normal growth of cell walls and when being deficient, the wall grows but is unable to make a new cell wall of peptidoglycan.

Note: To remember easily, muramic acid is mostly present in the cell wall of bacteria. It can be found in both gram-positive and gram-negative bacteria. In gram-positive bacteria, the cell wall is 20 to 80 nanometers thick while in gram-negative bacteria, it is 7 to 8 nanometers thick. The cell wall of gram-positive bacteria is thicker than the cell wall of gram-negative bacteria.