Let's look at what happens when a virus attacks our cells. Most viruses reproduce through a process called lytic infection. During lytic infection a virus enters the host cell, makes a copy of itself, and causes the cell to burst, or lyse.

Watch this video about the virus lytic cycle.

Directions: Study the following diagram. It shows the steps of the lytic cycle. The steps are outlined below.

Source: Adapted from Lytic Cycle, Discovery Health

1. Attachment: Virus attaches to the host cell.
2. Entry: Genetic material is injected into the host cell.
3. Replication: Virus takes over the cells metabolism causing the creation of new proteins and nucleic acids by the host cell's organelles.
4. Assembly: Proteins and nucleic acids are assembled into viruses.
5. Release: Virus enzyme cause the cell to burst and viruses are released from the host cell. These new viruses can infect other cells.

Test Yourself!

1. Which stage does the virus take over the cells metabolism?
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   replication
2. What causes the host cell to burst?
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   virus enzymes
3. At what stage is genetic material injected into the host cell?
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   entry