Question

Virus structure and function

a.What are the main structural components of a virus?

b.What does it mean to say that a virus shows host specificity (host range)?

c.What structural feature(s) help with host specificity?

Answer 1

a) The main three component of a virus structure are:

1. The genetic material: Virus have nucleic acid ( Either RNA or DNA) as their genetic material

2. Capsid: The Protein coat surrounding the genetic material to protect the nucleic acid from harm

3 Envelope: Some viruses have a lipid coating around capsid which helps in further protection and attachment to the host lipid membrane.

b) Virus shows host specificity means a particular virus can only attack some particular host cells such as plant, animal or bacteria. The type of cells that a virus can attack is specific to a particular virus. For example Plant viruses can only attack particular plant cells but not animal cells.

c) The viruses attaches to the host membrane due to presence of receptor in the host membrane. These receptors attaches to the particular attachment proteins in capsid or glycoprotein structures in envelope. The receptor of the host cell membrane and the attachment structure of the virus needs to be a perfect match for the virus to attach. As a viral attachment structure matches with only a few specific type of host cell receptor, it can only attack those cells becoming host specific.