Polyribosomes (polisomes) are intracellular complexes that synthesize proteins. Each complex consists of one molecule of messenger RNA (mRNA) and of a number of ribosomes. Polyribosomes are formed by consecutive binding of ribosomes to mRNA. The ribosomes move along a helix of RNA one after another. Each ribosome synthesizes a single protein chain, by reading of genetic information coded in the same mRNA. The model is initiated by the "Start" button. The "Stop" button interrupts the animation, while the "Reset" button returns it into initial state.