FoldLens Junior

Playing fair here

Be kind to the people you play with. Take turns, say how sure you are, and never tease anyone for a wrong guess: a wrong first guess is how checking starts. Nobody here needs your name. If something on this site worries you, tell a grown-up you trust.

For teachers

Every entry below carries an NGSS performance-expectation tag (MS-LS1-2, MS-LS1-3, MS-LS1-7, MS-LS3-1, MS-LS3-2) and a curated, peer-reviewable explanation. Teacher mode adds reflection prompts and iCloud-synced bookmarks — bookmarks only, never student data.

Privacy posture for kids and schools →

For platforms

Each protein has a canonical share URL at /junior/p/<slug> and a standard OEmbed endpoint. Drop a card into any LabXchange, WordPress, or Discourse page — discovery via <link rel="alternate"> or query at /junior/oembed?url=…&format=json.

The 50 starter proteins

• Insulin — Insulin is a signal your body sends out after you eat. It makes your cells take in sugar. Without it, sugar piles up in your blood.
• Hemoglobin (alpha) — Hemoglobin is the red stuff in your blood. Oxygen sticks to it in your lungs and comes off again out in your body.
• Hemoglobin (beta) — This piece pairs with alpha to make full hemoglobin. One tiny change in the beta gene, passed down from both parents, causes sickle cell disease.
• Green Fluorescent Protein — This protein glows bright green under blue light. Scientists attach it to other proteins so they can see where those proteins are inside cells.
• Alpha-amylase — This enzyme in your spit chops starch into sugar. That is why bread starts to taste sweet if you chew it for a while.
• Antibody (IgG) — Antibodies are Y-shaped grabbers your blood makes to catch germs. They lock onto a germ and flag it for the cleanup team.
• Myoglobin — Myoglobin sits in muscle and holds onto oxygen until your muscle needs a burst. It is why steak is red.
• Collagen — Collagen is the rope that holds your skin, tendons, and bones together. It is the most common protein in your body.
• Keratin — Keratin builds your hair, fingernails, and the top layer of your skin. It is tough because its chains stack tightly.
• Actin — Actin links into long cables inside muscle cells. When myosin pulls on those cables, your muscle squeezes shorter.
• Myosin — Myosin is a tiny motor inside muscle. Each time it uses up a bit of fuel called ATP, it changes shape and tugs on actin cables. Millions of tugs make a muscle squeeze.
• Trypsin — Trypsin lives in your small intestine. It snips proteins from food into smaller chunks your gut can use.
• Pepsin — Pepsin works in your stomach where the acid is strong. It starts breaking down protein in food right away.
• Lactase — Lactase splits the sugar in milk into two smaller sugars. Many people make much less of it after childhood, and then a lot of milk can upset their stomach.
• Catalase — Your cells make a chemical called hydrogen peroxide that can hurt them. Catalase chops it into water and oxygen, fast.
• Lysozyme — Lysozyme is in your tears, spit, and snot. It pops open the walls of bacteria before they can make you sick.
• Serum albumin — Albumin floats in your blood and carries hitchhikers like fats and medicines around your body.
• Ferritin — Ferritin is a hollow ball that stores iron safely inside your cells until your body needs it.
• Casein — Casein is the main protein in cow milk. Its tiny clumps, along with drops of fat, scatter light, so milk looks white.
• Ovalbumin — Ovalbumin is the main protein in an egg white. When you cook an egg, its shape changes and it turns from clear to white.
• Cytochrome c — Cytochrome c hands off electrons inside the parts of your cell that make most of its energy. Without it, a cell loses most of its energy supply.
• ATP synthase — ATP synthase is a real spinning motor inside your cells. Each full turn builds three new pellets of ATP fuel.
• Tubulin — Tubulin snaps together into long hollow tubes. Those tubes are the rails your cell uses to move things around.
• p53 — p53 is a safety switch. When DNA gets damaged, p53 builds up and switches on genes that stop the cell from dividing, or that make the cell self-destruct.
• DNA polymerase — DNA polymerases copy your DNA before a cell splits. This one, polymerase alpha, starts each new piece of the copy. Other polymerases carry the copying on and fix most mistakes.
• RNA polymerase II — This protein reads a gene in your DNA and writes a matching RNA copy. The cell uses that copy to build a protein.
• Histone H3 — Histones are spools that DNA wraps around. Without them, your DNA would not fit inside the cell.
• Ribosomal protein S6 — A ribosome is a tiny factory that builds proteins. S6 is one bolt that holds the factory together.
• CRISPR Cas9 — Cas9 is a scissors protein that bacteria use against viruses. Scientists turned it into a tool to edit DNA on purpose.
• SARS-CoV-2 spike — The spike is the crown on the coronavirus. It locks onto a protein on your cells so the virus can sneak in.
• ACE2 — ACE2 sits on the outside of your cells and helps control blood pressure. It is also where the COVID virus's spike sticks.
• Rhodopsin — Rhodopsin sits in the back of your eye. When light hits it, it bends, and that bend starts a signal that travels to your brain.
• Aquaporin-1 — Aquaporins are water channels in the thin membrane around your cells. They let water rush in and out without letting salt or sugar through.
• Dopamine D2 receptor — This protein catches a brain signal called dopamine. The signal matters for movement and reward.
• Acetylcholinesterase — Your nerves send a signal called acetylcholine to your muscles. This enzyme chops it back up so the signal turns off.
• Hexokinase — Hexokinase is the first step when your cell burns sugar for energy. It tags glucose so it cannot escape the cell.
• GLUT4 (glucose transporter) — GLUT4 is a sugar door on your muscle and fat cells. After you eat, insulin's signal brings more of these doors up to the cell's surface.
• Sodium-potassium pump — This pump uses fuel to push sodium out of your cell and pull potassium in. Your nerves and muscles need this gap to work.
• CFTR — CFTR is a salt channel on lung and gut cells. A broken CFTR causes cystic fibrosis, a lung and digestion disease.
• Tyrosinase — Tyrosinase makes the brown pigment in your skin, hair, and eyes. Different gene versions make different amounts.
• Lactoferrin — Lactoferrin in milk and tears holds on tightly to iron, so germs nearby get less of it. Germs need iron to grow, so this slows them down.
• Beta-lactoglobulin — This is the main whey protein in cow milk. It is one of the proteins that some people are allergic to.
• Silk fibroin — Silkworms spin their cocoon out of fibroin. It packs into tight sheets, which is why silk thread is so strong.
• Antifreeze protein (type I) — Some fish in icy water make this protein. It sticks to tiny ice crystals so they cannot grow big enough to hurt the fish.
• Firefly luciferase — Luciferase is the enzyme that makes a firefly's tail glow. It helps a chemical called luciferin react with oxygen, using ATP fuel, and that reaction gives off light.
• Alpha-crystallin A — This protein packs tightly into your eye lens so it stays clear. As we get older, it slowly tangles, and lenses can cloud over.
• Hemagglutinin (H1N1 flu) — Hemagglutinin is the spike on flu viruses. It sticks to cells in your nose and throat, which lets the virus get in.
• RuBisCO — RuBisCO is how plants take carbon out of the air to build sugar. It is part of the engine of photosynthesis.
• Aldolase A — Aldolase is a sugar-cutter. It splits a six-carbon sugar in half so your cells can keep pulling energy out of it.
• Growth hormone — Growth hormone is a signal from a small gland just below your brain. Your body releases most of it during sleep, and it helps you grow taller.

How we build it

FoldLens Junior is the K-12 sibling of FoldLens. Both apps consume FoldKit, our shared open-source Swift library. Junior adds the tier-appropriate voice, the age gate, the curriculum mapping, and the classroom-friendly renderer tuning.

Source code is private until v1.0 and goes public under Apache 2.0 at launch. Content is CC BY 4.0.