system
Given the following post, respond as if you're commenting on Reddit:
human
Since paper comes from wood (and trees are obviously cellular lifeforms), could you look at a piece of paper through a microscope and see plant cells, or does the process of turning it into paper destroy or cover up these cells?
gpt
Nope, no cells left. Paper is mainly just cellulose fibers, and doesn't have to be made out of wood - historically hemp, flax, cotton and others were used, and rag-and-bone men would collect old rags to sell to paper-makers. Making paper out of wood didn't come along until the 19th century, first with mechanical pulping and then chemical. 'Pulping' being the process of breaking down the wood and getting the fibers. 

Unlike plants, wood contains lots of the substance lignin, a massively branched polymer which is basically the defining difference at the cellular level between wood and other plant matter. Chemical pulping involves breaking it down to liberate the cellulose fibers from the lignin. High quality paper has all the lignin removed, because it's the lignin that degrades and causes paper to yellow, not the cellulose. (So mechanically pulped wood paper in a book from 1840 has typically yellowed much much more than cotton paper from 1740, all else being equal) Anyway, in the Kraft process used to make paper today, wood is first broken into tiny chips, and then boiled in a digester full of hot lye and other chemicals that break down the cells and lignin and other stuff. (which is usually recovered and burned to power the process; paper mills are often self-sufficient on energy)

So in an electron microscope, paper just looks like a mess of fibers, there are no cell structures visible since there's nothing left of the cells after digestion.