• Question: What is the structure of a virus and are they living things?

    Asked by cbond on 29 Apr 2020.
    • Photo: anon

      anon answered on 29 Apr 2020:

      The structures of virus’s can differ on a case by case basis. But in the case of influenza (commonly called Flu), the virus can appear as spherical ‘buds’ or can appear as long filaments. In both cases the virus consists of an RNA genome surrounded by a lipid membrane. On the inside of the virus attached to the membrane is a layer of protein arranged as a matrix, in the case of Flu the protein in the matrix is called ‘M1’. On the outside of the virus attached to the virus are a range of ‘spike’ proteins. These are proteins that protrude from the surface of the virus and look like spikes. It is often the spike proteins that are first recognised by our immune systems and are the targets of most vaccines.

      Virus’s are not classed as living things because they are unable to replicate themselves/multiply without the assistance of a host cell.

    • Photo: Kim Liu

      Kim Liu answered on 29 Apr 2020: last edited 29 Apr 2020 3:40 pm

      A virus is only really made of two things – genetic material and a coat to protect it. The coat is usually made of proteins and fats, with the precise structures varying with different virus types. A virus coat also carries special proteins which will allow it to break into a cell for infection. Something I find amazing is that the building blocks of a virus are able to assemble itself inside the cell, just by bumping into each other.
      Whether or not a virus is alive is a question of definition; what stops them being always considered alive is the fact that they cannot replicate by themselves. They cannot make copies of themselves without infecting a cell.

    • Photo: Spyros Lytras

      Spyros Lytras answered on 29 Apr 2020: last edited 29 Apr 2020 4:59 pm

      A virus is made of genetic material, usually covered in a protein coat and sometimes also covered in an envelope (similar to our own cells). The fascinating thing about virus structures is how amazingly diverse they can be! Viruses can go from very tiny to very large (in a microscopic sense), some viruses can even form tiny crystals, while even viruses can get infected by other even smaller viruses! Some viruses are spherical and can have tiny spikes (like coronaviruses), some look like a rod (like Ebola) and some look like a tiny spaceship (like bacteriophages).

      Your second question is quite hard to answer even for virologists… Viruses certainly do not think or feel like animals or humans do, but they do have genomes like every living organism. I guess the answer really depends on what your definition of a living thing is! I personally like to think of a virus as a very very complicated chemical.

      If you want have a look at some virus structures, some colleagues of mine have made an excellent virus colouring book with a lot of information about different viruses you can find here:
      and some extra pages here: https://www.gla.ac.uk/researchinstitutes/iii/cvr/events/public%20engagement/colour/