Episode summary

Right now, inside every cell in your body, trillions of microscopic factories are assembling molecules called peptides — the short chains of amino acids your body uses to talk to itself, from insulin to oxytocin. But how does your body actually build one? In this episode we follow a single peptide all the way from blueprint to finished product, using the real scientific terms but giving you a picture for every one. We start in the "library" of your DNA, where each recipe is written in three-letter words called codons, then watch the cell make a disposable photocopy — messenger RNA — so the precious original never has to leave. That copy travels to the ribosome, the cell's assembly line, where a fleet of molecular "delivery trucks" brings exactly the right amino acids and snaps them into a chain, bead by bead ...