The document shows the process of protein synthesis: 1) In the nucleus, RNA polymerase unzips DNA and copies its sequence into a messenger RNA (mRNA) strand. 2) The mRNA exits the nucleus through the nuclear pore and enters the cytoplasm. 3) In the cytoplasm, the mRNA binds to a ribosome which reads its sequence in groups of three bases (codons). 4) Transfer RNA (tRNA) molecules matching these codons bring specific amino acids to the ribosome. 5) The amino acids are linked together to form a polypeptide chain, which later folds into a functional protein.