Question

Human tears contain an enzyme called lysozyme which damages the cell walls of bacteria. Which of the following best explains how this enzyme functions???

A. Lysozyme kills bacteria by engulfing them.
B. Lysozyme breaks through bacterial cell walls, killing the bacteria.
C. Lysozyme catalyzes a reaction that breaks down bacterial cell walls.
D. Lysozyme is destroyed as it digests bacterial cell wall molecules.

Answer 1

Lysozyme present in human tears functions by catalyzing a reaction that breaks down the peptidoglycan layer in bacterial cell walls, resulting in the destruction of the bacteria without the enzyme being consumed or destroyed in the process.

C is correct

Step-by-step explanation:

The function of the enzyme lysozyme present in human tears is best explained by option C: Lysozyme catalyzes a reaction that breaks down bacterial cell walls. Lysozyme is an enzyme which, by its nature, facilitates chemical reactions without being consumed in the process.

It targets the peptidoglycan layer of the bacterial cell wall, a component unique to bacteria, catalysing hydrolytic reactions that cleave the glycosidic linkages in peptidoglycan, leading to holes in the bacterial cell wall. Eventually, this compromises the integrity of the bacterial cell wall and can result in the lysis (destruction) of the bacterial cell due to osmotic imbalance. This is crucial as it helps to control the population of bacteria and serves as a defensive mechanism against infection.

Answer 2

C. Lysozyme catalyzes a reaction that breaks down bacterial cell walls.