In a eukaryotic cell, the final stage of protein synthesis takes place in the cytoplasm after the initial stage, which happens in the nucleus. In a prokaryotic cell, there is no need for the second stage of the process.
The information on how to synthesize protein is contained in DNA. The DNA molecules constitute a set of instructions for each cell on how to consume energy, grow, reproduce and expel waste. However, DNA is only the code. To make these code into instructions that parts of a cell can read, ribonucleic acid, or RNA, is needed. Messenger RNA, or mRNA, plays a key part in the process of protein synthesis.
The first stage of protein synthesis is transcription. In a eukaryotic cell's nucleus, segments of the double-stranded DNA molecules are turned into single strands of RNA molecules called transcripts. These transcripts are then processed into mRNA. Prokaryotic cells are different in that their transcripts can serve as mRNA immediately.
The second stage of protein synthesis in a eukaryotic cell is called translation. This takes place in the cell's cytoplasm. During this stage, genetic information is transferred from RNA to protein. Peptide bonds between amino acids are formed and thus protein is synthesized.