The virus follows several steps for its reproduction: First, it adsorbs to superficial protein anchors of the cell membrane. Then it penetrates the cell. Inside the cell, it uncoats its viral nucleic acid out of the protein envelope. The nucleic acid can be DNA or RNA. The following protein biosynthesis can take place in the cytoplasm or the nucleus, where the DNA is transcripted into RNA. If its an RNA virus, it first needs to create DNA out of its viral RNA strand with the enzyme reverse transcriptase. After several viral structure proteins have been produced in the host cell, these proteins assemble and form a complete properly functioning virus particle. This process can happen without any enzymatic help by the cell. Finally, the new virus particles are packed into membrane evaginations and released out of the cell as virions.