Question

Where does the enzyme Lysozyme that catalyzes the destruction of the cell walls cleaves?

A - Lysozyme is a DD-transpeptidase that cleaves the cross-linked peptidoglycan chains.

B - Lysozyme is a glycoside hydrolase that catalyzes the hydrolysis of 1,4-beta-linkages between N-acetylmuramic acid (NAM) and N-acetyl-D-glucosamine (NAG) residues in peptidoglycan.

C - Lysozyme forms a peptide bond between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water (H2O).

D- No idea whatsoever ???

Answer 1

The answer is B. Lysozyme is a glycoside hydrolase that catalyzes the hydrolysis of 1,4- beta -linkages between N-acetylmuramic acid (NAM) and N-acetyl D-glucosamine(NAG) residues in peptidoglycan.

Description: Bacterial cell walls contain a layer of peptidoglycan in which the specific site that lysozyme targets. This peptidoglycan layer contains alternating molecules of NAM and NAG linked by beta-(1,4) bonds. As a glycoside hydrolase, lysozyme targets this linkage resulting in bacterial death.

Option A is not supporting as this lysozyme is not a transpeptidase enzyme. Transpeptidase catalyzes the cross-linkage of peptidoglycan in bacterial cell walls.

Option C is not supporting, It does not form a peptide bond. As it is a hydrolase, it carry out hydrolysis which transfers the functional groups to water and does not release the water molecule.