Virulent phages replicate actively and cause lysis. The 4 steps of the lytic cycle are:
1. Attachment- the whole virus or just the nucleic acid (DNA or RNA) enters the host cell’s cytoplasm.
2. Synthesis- the nucleic acid takes over the host’s replicating mechanism. The host cell now begins making components for the virus. E.g: capsid proteins, nucleic acids, etc.
3. Assembly- the “parts” made by the host are brought together, thereby making new viruses.
4. Release- lysis (destroying of the cell) occurs, and the new viruses that were made using the host, are released into the body.
Temperate phages lie dormant in the lysogenic cycle, but a stimulus can trigger them into entering the lytic cycle, thus becoming virulent.