Transcription, the synthesis of RNA from a DNA template, occurs primarily within the nucleus of eukaryotic cells. This compartmentalization allows for the physical separation of DNA from the cytoplasmic machinery involved in subsequent steps. In prokaryotic cells, lacking a defined nucleus, this process takes place in the cytoplasm alongside the genetic material. The resulting RNA transcript then undergoes processing before exiting the nucleus in eukaryotes.
Translation, the process of synthesizing a polypeptide chain based on the information encoded in messenger RNA (mRNA), predominantly occurs in the cytoplasm. Ribosomes, the molecular machines responsible for this synthesis, bind to mRNA and, with the assistance of transfer RNA (tRNA), assemble amino acids into a protein. In eukaryotes, translation can occur on free ribosomes in the cytoplasm or on ribosomes bound to the endoplasmic reticulum, targeting the newly synthesized protein to specific cellular locations or for secretion.
