A common way of preserving food and organisms is immersion in alcohol. But what causes alcohol to preserve these items well?
Alcohol kills bacteria and fungus, put simply. It does this as its metabolism products cause damage directly to the DNA, and directly to the cell respiration process. It also happens to tend to dry it out.
We can drink alcohol safely because of our alcohol dehydrogenase enzyme, which breaks the toxic alcohol into useful byproducts, that we can use for energy.
Also, it's a matter of scale. Consider submerging yourself in alcohol for a period of time. Don't you think you'd probably die, too?
It's very important to note that alcohol strength matters in this case. It also depends strongly on type. For example, ethyl alcohol: we drink this kind. It's not as toxic as say, methyl alcohol, or isopropyl alcohol. Those last ones are used as preserving and disinfecting agents, respectively.
All life on earth is adapted to work in water, and only in water. The most basic level of life is enzymes producing proteins, and energy, to produce more enzymes. Cells, DNA, etc. are the directing structure for that.
In the wrong medium, e.g. 5% ethanol, the reactivity of the enzymes is totally off, not speaking of actual toxic effects of ethanol, acetaldehyde etc. One after the other of the thousands of chemical reactions, the equillibrium of which is life, take wrong turns and go into stalemate. And that is the end of it. The enzymes are no longer regenerated, what remains are all the membranes in the cells, which you can look at in your microscope.