Protein synthesis takes place in two main cellular locations:
- Transcription occurs in the nucleus of eukaryotic cells, where a gene's DNA sequence is copied into messenger RNA (mRNA)
. In prokaryotes, which lack a nucleus, transcription occurs in the cytoplasm
- Translation occurs in the cytoplasm at the ribosomes, where the mRNA is read to assemble amino acids into a polypeptide chain (protein)
. Ribosomes may be free-floating in the cytoplasm or attached to the rough endoplasmic reticulum in eukaryotic cells
In summary, protein synthesis starts in the nucleus (transcription) and finishes in the cytoplasm at ribosomes (translation) in eukaryotic cells, while in prokaryotes, both processes occur in the cytoplasm
