The chemical bonds in peptidoglycan can be hydrolyzed by which enzyme found in tears and saliva?

The correct answer is lysozyme, which is an enzyme found in various body fluids, including tears and saliva. Lysozyme is known for its ability to hydrolyze the glycosidic bonds in peptidoglycan, a key structural component of bacterial cell walls. By breaking these bonds, lysozyme disrupts the integrity of the bacterial cell wall, leading to cell lysis and contributing to the body’s innate immune response against bacterial infections.

This activity of lysozyme is particularly crucial in the eyes and mouth, where it helps prevent infections by targeting and degrading the cell walls of potentially harmful bacteria, thereby playing a significant role in first-line defense mechanisms.

Other enzymes mentioned do not have this specific function: DNA polymerase 1 is involved in DNA replication and repair, amylase primarily catalyzes the breakdown of starch into sugars, and pepsin is a digestive enzyme that works on proteins in the stomach. Thus, lysozyme is unique in its ability to target the bonds in peptidoglycan, making it the correct choice.