What are the parts of a virus?
- Nucleic acid
- Capsid
- Envelope
- Envelope spikes
These components are essential for the structure and function of viruses.
Which parts do ALL viruses possess?
- Capsid
- Nucleic acid (DNA or RNA)
- Spikes (envelope or capsid spikes)
These components are fundamental to the viral structure.
Which part do some viruses possess?
Envelope
The envelope is not present in all viruses, but it plays a crucial role in some.
What is the function of nucleic acid in a virus?
Viral genome contains DNA or RNA, carries genes necessary to invade host cells and redirect cells’ activity to make new viruses
Nucleic acid is essential for the replication and infection process.
What is the function of the capsid?
- Protects the nucleic acid when outside the host cell
- Helps the virus bind to a cell surface
- Assists in the penetration of viral DNA or RNA into a suitable host cell
The capsid is made up of protein subunits called capsomeres.
What is the function of the envelope?
- Protects the nucleic acid when outside the host cell
- Helps the virus bind to a cell surface
- Assists in the penetration of viral DNA or RNA into a suitable host cell
The envelope is a lipid layer that surrounds some viruses.
Define host range in relation to viruses.
The spectrum of cells a virus can infect
Virus/host cell interaction is usually very specific due to tissue tropism.
What is tissue tropism?
Cells or tissues of a particular host that support the growth of a particular virus
Tissue tropism explains why some viruses infect specific types of cells.
What are prions?
An infectious protein that can cause disease
Prions are known to cause spongiform encephalopathies.
True or false: Prions are viruses.
FALSE
Prions are infectious proteins, not viruses, and they cause different types of diseases.
