This document summarizes the processes of transcription and translation in 3 steps: 1) Transcription occurs in the nucleus, where RNA polymerase copies DNA sequences into messenger RNA (mRNA) that is exported into the cytoplasm. 2) Translation occurs in the cytoplasm using transfer RNA (tRNA) and ribosomes to read the mRNA codons and add amino acids to form a polypeptide chain according to the genetic code. 3) The polypeptide is completed when the ribosome reaches a stop codon, resulting in a full protein molecule.