The term "protein synthesis" refers to the making of a protein. This process begins in the nucleus and then continues in the ribosomes. Protein synthesis is comprised of two parts: DNA transcription and DNA translation.
During transcription, a section of DNA acts as the template to build a messenger RNA, or mRNA, strand. The mRNA strand then traverses the nuclear envelope and enters a ribosome. The ribosome holds the mRNA strand in place, while other RNA molecules, called transfer RNA, carry amino acids, the building blocks of protein, to the ribosome. Each tRNA molecule has a side called an anticodon that matches up with, or complements, a section of the mRNA molecule called a codon. The tRNA molecule then releases its amino acid cargo and detaches from the mRNA strand, while the amino acid bonds to the growing protein strand.