Ribosomes play a key role in protein synthesis by assembling amino acids into polypeptide chains based on the mRNA code. The genetic code is translated as mRNA is read three bases at a time (codons) by ribosomes to determine which amino acid to add to the chain. This process continues until a stop codon is reached, at which point the protein is released and translation is complete. The central dogma of molecular biology explains that genetic information flows from DNA to RNA to protein.