During transcription, complementary mRNA strands are created when the base codes in DNA are copied. From here, the mRNA strands move out of the nucleus and into the cytoplasm. mRNA serves as the code for assembling amino acids in a certain order to create proteins. This takes place at the site of the ribosome and is known as translation. Ribosomes are made of another type of RNA known as rRNA, and this molecule makes protein synthesis at the ribosome possible. Another type of RNA called tRNA brings amino acids to the ribosome and attaches them in the specific order that is on the mRNA. Peptide bonds link the amino acids, and this is how proteins are formed (DiscoveryEducation).