VerbSnap
A tiny game about how we say what proteins do. It is easy — and wrong — to write that a protein wants, hunts, decides or walks. Real molecules only jitter, bump, and stick when a shape fits. Each round shows a claim; call it Mechanism (honest physics) or Purpose (teleology) before the timer runs out. Nothing is installed; nothing about you is collected.
This is the tool — a free learning game with no login and nothing tracked. The claim bank is shown in full in the guide below, which works with or without JavaScript. The point isn’t to score high; it’s that the trap gets harder as the timer shrinks. Teleology creeps back under time pressure — that is a real, documented effect in adults, not a gimmick.
Loading the game… If it does not start, the full claim guide below still works.
How to play. Press Start. A claim about a protein appears with a shrinking timer. Decide whether it is written as honest Mechanism or as Purpose (teleology) and choose — tap a bin, click a button, or press 1/M for Mechanism, 2/P for Purpose. There is no way to lose: a purpose claim reveals its banned verbs and its honest rewrite. If the timer runs out, the claim reveals itself and the round moves on.
The no-intent verb lint
Fold Commons writes protein stories under a verb lint: a short list of intent-words that are banned because they smuggle in a goal a molecule cannot have. A protein does not want, try or decide; it is jostled, and sometimes a shape fits and sticks. These are the banned verbs the game is built on:
wantstriesdecidesknowssearches forhuntsgoes toin order tosacrificesgets tiredlearns
A claim is Purpose if it uses one of these (or any other intent framing); it is Mechanism if it describes only what the molecules do — jitter, bumps, shapes that fit, concentrations that fill and empty. “Recognises” and “its job is to” are allowed only when the very next clause gives the mechanism.
The claim bank
Every claim in the game is one biological fact written two ways. The Purpose column trips the verb lint (the banned verbs are marked); the Mechanism column is the honest rewrite the game rewards.
| Topic | Purpose (trips the lint) | Mechanism (honest rewrite) |
|---|---|---|
| Enzyme meets substrate | Picky searches the cell for the one molecule she can help. banned: searches, help | Picky is bumped into thousands of times. Most bumps do nothing. When a shape fits, it sticks, and the reaction happens. |
| Hydrophobic core | Shy Core hides inside because it hates water. banned: hates | Shy Core ends up inside because water keeps shoving the oily parts together until they are tucked away. |
| Antibody | The antibody hunts the germ down and locks it up. banned: hunts, locks | The antibody drifts until it bumps a shape that fits its tips. Then it sticks, and the germ is flagged for the clean-up cells. |
| Oxygen carrier | Hemoglobin picks up oxygen in the lungs because the body needs it. banned: picks up, needs | In the lungs there is so much oxygen that hemoglobin’s pockets fill. In the muscle there is little, so the oxygen lets go. |
| Molecular motor | Myosin walks along the actin cable, pulling the muscle. banned: walks, pulling | Myosin is jostled constantly. ATP makes the backward step less likely than the forward one, so on average it moves along the cable. |
| Channel / gate | Gate guards the cell wall and decides who gets in. banned: guards, decides | Gate lets water through because only water fits the door. |
| Mutation | One wrong letter breaks the protein. banned: wrong, breaks | One changed letter can change the fold. Sometimes nothing happens; sometimes the shape can’t do its job any more. |
| AlphaFold prediction | AlphaFold worked out the shape of this protein. banned: worked out | AlphaFold made a very good guess at this shape. A guess stays a guess until an experiment checks it. |
| Chaperone folding | The chaperone tries to fix the tangled protein, and if it fails it decides to destroy it. banned: tries, decides | The chaperone’s pocket opens and closes as ATP binds and lets go. A floppy chain that keeps sticking gets more chances to settle, or is passed on to be taken apart. |
| Signalling receptor | The receptor knows its hormone and goes to meet it at the surface. banned: knows, goes to | Hormone molecules drift past the surface. When one fits the receptor’s pocket it sticks, and the receptor’s shape shifts on the inside. |
| Cargo transport | Kinesin wants to deliver its cargo, so in order to reach the end it never gets tired. banned: wants, in order to, gets tired | Kinesin is jostled at every moment. Each ATP makes a forward attachment a little more likely than a backward one, so the cargo drifts toward the track’s plus end on average. |
| Adaptive immunity | The T cell learns the virus and sacrifices itself to protect the body. banned: learns, sacrifices | Among many T cells with different surface shapes, the few whose shape happens to fit a viral piece stick, and those are the ones that copy themselves. |
Methods & about
This is a teaching game, and it is honest about being a simplification. The “Purpose vs Mechanism” line is not always sharp — some words (“recognises”, “its job is to”) are fine when the mechanism follows immediately. The game uses the strict reading: if an intent verb stands alone, it is Purpose. The claims are authored from the Fold-Commons narrative-method bible (§5.1 no-intent law and §5.2 do/don’t pairs); the misconception it targets — promiscuous teleology, which returns in adults under time pressure — is from Kelemen & Rosset (2009). Every claim is written by hand, not generated. The game keeps no score history, uses no accounts, and sends nothing anywhere.
Want the deeper, native experience? See the Fold Commons apps. Everything we make is free and non-profit; learn more on the home page.