Viruses can only replicate in specific scenery,
As their propagation requires host cell machinery.
These submicroscopic agents arguably aren’t alive,
Because without a host cell, viruses just can’t survive!
Outside the cell are virions,
With protein coats or capsids, which have nucleic acid in their interiors.
The capsid is made up of proteins arranged in a neat array,
With helical or icosahedral symmetry displayed.
When the viral genome is found inside of the capsid,
These two together are called the nucleocapsid.
In an envelope some viruses are enclosed,
Which of host cell membrane are composed.
Replication, packaging, delivery-assisting proteins,
Are encoded for in DNA and RNA in genes,
In addition to proteins that change cell structure or function,
In order to increase the host cell’s virus production.
Viruses attach to cell-surface receptors of new host cells,
Ubiquitous or unique to cells in which the virus dwells.
Viruses usually use one type of host-cell receptor,
Some viruses can trick more than one type of receptor.
Then they enter by pore formation, membrane fusion, disruption,
After entry come six more steps of viral replication,
Virion disassembly, viral genome replication, transcription and translation,
Then assembly, and release of the creation.
Nonenveloped viruses mostly escape their host through lysis,
Or host cell membrane rupture - yeah, it’s not the nicest…
Enveloped viruses use budding, using host membrane supplies,
Using up the cell membrane, up until the host cell dies.
Since the host performs most of the steps in viral replication,
It’s hard to kill a virus without host aggravation,
Vaccines are key to stop virus spread in communities,
When enough people get them, we get herd immunity!
Music/Lyrics/Visual © Neural Academy
