Protein synthesis involves two main steps: transcription and translation. During transcription, DNA is copied into messenger RNA (mRNA) in the nucleus of a cell. The mRNA then travels to the cytoplasm, where it is used as a template to assemble a chain of amino acids during translation. This process is facilitated by ribosomes and transfer RNA (tRNA), which bring amino acids to the ribosome and match them to the codons on the mRNA. Once the chain is complete, it folds into a functional protein.