Final answer:
Quaternary Ammonium Compounds work by disrupting the phospholipid plasma membranes of bacteria leading to the death of the cell.
Step-by-step explanation:
Quaternary Ammonium Compounds (quats), such as benzalkonium chloride and cetylpyrimidine chloride, detrimentally affect bacteria by infiltrating and disrupting their phospholipid plasma membranes. This action leads to the death of the bacterial cell. Quats are amphipathic with both hydrophobic and hydrophilic ends, allowing them to integrate into the bacterial membrane similarly to phospholipids. The disruption of membrane integrity takes place, leading to the leakage of cellular contents and bacterial death. Being cationic, they carry a positive charge that contributes to their antimicrobial properties. Quats are useful as they are stable, non-toxic, and inexpensive, making them a common choice for antiseptics, and for disinfecting surfaces in clinical settings. They are found in household cleaners, skin disinfectants, and mouthwashes, and have been effective against fungi, protozoans, and enveloped viruses, while endospores remain resistant.
Soaps are not considered disinfectants because they primarily act by lowering surface tension to wash away microbes mechanically, without necessarily killing them. They do not have the same membrane-disrupting effects as quats.