system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What exactly is alcohol, and why does it kill basically everything?
gpt
'Alcohol' describes a group of chemical compounds that are created by yeasts when they break down natural sugars in grains or fruits during a process known as 'fermentation'.

There are different types of alcohol (eg ethanol, methanol and propanol) but what they all have in common is a 'hydroxyl' group, which is a chemical structure that is very effective at bonding to other molecules. This tends to dissolve the molecules that it bonds to.

That's how alcohol kills microbes - by dissolving their protective membranes and then reacting with the stuff inside.