How Does Soap Clean Dishes and Kill Bacteria?

A short video explaining the structure of soap, how it cleans stuff, and how it kills stuff. I hope that you guys all learned something new from this video :) Timestamps: 00:00 Intro 00:16 Structure of soap 01:03 How soap cleans stuff 02:06 How soap kills stuff 02:54 Summary Music: https://www.youtube.com/watch?v=Wc72E1j9RRY Song title: K/DA Beats for Lo-fi Legends Artist: Legends of Runeterra Courtesy of Riot Games: https://www.leagueoflegends.com/en-gb/news/community/riot-music-creator-safe-guidelines/ Sources: https://www.pfizer.com/news/articles/how_soap_works_the_science_behind_handwashing https://www.nytimes.com/2020/03/13/health/soap-coronavirus-handwashing-germs.html https://www.thoughtco.com/how-dos-soap-clean-606146 https://www.ipcol.com/blog/an-easy-guide-to-understanding-surfactants/ Transcript: All of us have heard countless voices babbling about washing our hands, especially during a certain event for the past few years. But how does soap even work? In this video, we will explore the mechanisms of a soap, how soap cleans stuff, and how soap kills stuff. Starting off with the anatomy of a soap, it is made of fats from animals, plants, or minerals, and alkali, which are bases that neutralize acids. Through a chemical reaction called saponification, soaps are made, with each soap molecule consisting of a head that is hydrophilic, which loves water, and a tail of a long chain of carbon and hydrogen that is hydrophobic, which hates water but loves oils and fats. This shape makes soap molecules a surfactant, meaning that it is a compound that lowers the surface tension of a liquid, which is how much a liquid wants to attract to each other. At high concentrations in a water solution, these soap molecules form this configuration called a micelle, where the heads are sticking out, and the tails are sticking in, away from the water. With the basics of soap out of the way, how does soap clean our dishes? As mentioned earlier, the hydrophobic tails of a soap molecule hate water, but are attracted to fats and oils, which are common on the plates that we want to wash. When washing the dishes with soap, the hydrophobic tails are attracted to the grease and dirt, which contains fatty acids, on the plate. With enough of those tails, a new micelle is formed with the junk suspended inside. Then, after a quick rinse, all of those junk micelles get washed away, leaving us with plates with no stains. So on top of being surfactants, this also makes soap emulsifiers, which are compounds that allow things that don’t mix mix together. In this case, oil doesn’t mix with water, so that’s why it’s hard to rinse oil off of plates with just water. But with the help of soap, which traps the oil inside, oil is able to mix with the water and get washed away. Furthermore, speaking of surfactants, because soap also lowers surface tension, it prevents grease droplets from getting too large to be engulfed and washed away. And of course, very similar principles apply to how soap kills bacteria as well. Compared to hand sanitizers, which only kills microbes on our hands, soap also washes those microbes away, along with any other grease on our hands. In the case of bacteria and viruses, their cell membrane is also made of fatty acids, which the hydrophobic tail of the soap is attracted to. This means that when we are washing our hands, the soap micelles attract to the microbe cell membranes and try to wedge themselves inside them, causing probably a painful death. And once killed, the soap molecules then surround the dead microbe parts like they did with the grease on plates, and form micelles full of dead cell parts. Lastly, they are rinsed away by water, carrying the dead microbes with them. So soap is pretty much a pin needle popping balloons that are the microbes, quite effective too! And there we have it! Soap is made of a hydrophilic head and a hydrophobic tail, making this structure a surfactant and emulsifier, which lowers the surface tension of a fluid and mixes substances that usually don't mix. By either surrounding grease on a plate, or piercing through a microbe and engulfing its remains, soaps do a fantastic job at cleaning things that shouldn’t be where they belong. I hope that y’all have learned something interesting today, thank you for watching, and stay hydrated! #soap #chemistry #science