Que. Why do we use soap in the defence against germs?
Ans.: Germs, or microbes, are everywhere. In the air, soil, water and on every surface, including our body. Most microbes are harmless and some are important for human health, like the ones that live in our gut. But there are several germs that cause problems, and these are the ones we prefer not to have on or in our bodies. Our first line of defense against those harmful germs is soap.
Soap is a mixture of fat or oil, water, and an alkali, or basic salt. When those ingredients combine in the proper proportions, they go through a chemical process called saponification, which results in soap.
Soap and water work through the hydrophobic effect, a basic chemistry concept that explains why oil and water don’t mix.
Soap molecules have hydrophilic heads—meaning they cling to water molecules—and tails that are hydrophobic—which means “water-fearing.” When immersed in water, the soap molecules form into tiny balls, called micelles, with their hydrophobic tails pointed inwards. While the soap molecule tails want to avoid water, they are attracted to oils and fats.
Many bacteria and viruses, including coronaviruses, are encased in a fatty acid membrane. In the most simplistic terms, the soap molecule tails poke into these bilayer membranes, breaking them apart, and destroying the pathogens.