Final answer:
Lysozymes and certain types of antibiotics, such as β-lactam antibiotics, assist in breaking down peptidoglycan, an essential component of bacterial cell walls, contributing to bacterial cell lysis.
Step-by-step explanation:
Substances that aid in the breakdown of peptidoglycan include enzymes such as lysozymes, which are found in tears and egg whites, and various types of antibiotics. Lysozymes attack the peptidoglycan by breaking the bonds between the sugar molecules in the cell wall, leading to the weakening and eventual lysis (rupturing) of the bacterial cell. Antibiotics, particularly those in the β-lactam class like penicillin, inhibit the synthesis of peptidoglycan, which is a critical component of the bacterial cell wall, making the cells more prone to osmotic lysis. This illustrates the principle of selective toxicity, as human cells do not have peptidoglycan cell walls; thus, these antibiotics can target bacteria without harming human cells.