Question

How do chemicals in skin and mucous membranes defend against pathogens? List and briefly explain the function of 4 CHEMICALS counteracting microbial growth. Please do not talk about physical mechanisms of control

Answer 1

The chemicals secreted by epithelia lining the skin and the mucous membrane includes antimicrobial peptides or proteins. These proteins kills the broad spectrum of pathogens by disrupting their membranes.

And acidic ph, digestive enzymes are also the chemical barriers for the pathogen.

4 chemicals counteracting pathogen growth -

1. Lysozyme - it is found in tears, saliva. It cleaves glycosidic bond of the peptidoglycan , found in their cell wall. It leads to cell lysis.

2. Lactoferrin - found in the mucous secretion of respiratory, urinogenital tract . It binds to and sequester the iron which leads to decrease in the pathogen growth . It also disrupts their cellular membrane .

3. Defensins- this disrupts the membrane of pathogens , kills them.

4. Surfactant proteins - these block the bacterial surface components and promote phagocytosis of pathogen.