Every shape below was measured atom-by-atom in a real experiment, then deposited in the Protein Data Bank. Drag to rotate, scroll to zoom. You are looking at something far smaller than the wavelength of the light reaching your eye.
Look up any of the 200,000+ experimental structures by its 4-character ID at rcsb.org and type it in above. Built with 3Dmol.js; the entire viewer is the ~30 lines of code in the article.