Getting started

Welcome to Molecular Machines — a place to learn how biology's tiniest machines actually work, with the real crystal structures rendered live in your browser.

How the viewer works

• Drag to rotate
• Scroll to zoom
• Right-drag to pan

Each viewer also has a mode toggle in the top-right corner. Proteins open as a smooth surface — the clearest read of overall shape and how subunits pack — but you can switch to ball-and-stick (every atom a ball, every bond a stick), space-fill, or cartoon to see the chemistry and the fold. The structures come straight from open databases — no curation, no simplification. What you see is what crystallographers and cryo-EM microscopes actually measured.

A first molecule

Here is caffeine, fetched live from PubChem. It is small, familiar, and a good warm-up before we look at proteins.

A first protein

And here is hen egg-white lysozyme — one of the earliest enzyme structures ever solved (1965). It opens as a surface, showing its compact overall shape. Switch to cartoon to trace the backbone winding through space, or ball-and-stick to see the side chains poking into the solvent — including the cleft where the enzyme clamps onto and cleaves a bacterial cell wall.

That's all the orientation you need. Next, head to Molecular motors and pumps to meet biology's tiniest engines — and try the interactive Machines section, where some of them spin, step, and pump in a looping animation.