The source describes the process of protein synthesis, using the analogy of a chef following a recipe to make a dish. It explains that DNA serves as the original, protected recipe, located within the cell's nucleus. To create the final protein product, a copy of this recipe is made in the form of mRNA during a process called transcription, which occurs within the nucleus. This mRNA then leaves the nucleus to be translated into a chain of amino acids by ribosomes in the cytoplasm, a process aided by tRNA molecules. The source emphasizes the efficiency of this process, with multiple ribosomes working on the same mRNA to produce many protein copies simultaneously.