Protein
Etymology
From Greek "proteios" (primary, of the first rank), from "protos" (first), a name proposed by Berzelius and used by Mulder in 1838 to signal that these are the most fundamental substances of life.
noun · /PROH-teen/
A large molecule built from chains of amino acids that does most of the working jobs inside living cells.
What it names
The workhorse class of molecules — enzymes, antibodies, muscle fibers, hair — that carry out the instructions genes merely store.
Example
Your DNA is just the recipe; the proteins it codes for are what actually digest your food and fight infection.
Related idea
A gene is the instruction; a protein is the product built from it. The dietary “protein” on a nutrition label is the same class of molecule, broken down and reassembled into your own.