• Question: What are viruses ?

    Asked by anon-251721 on 24 Apr 2020. This question was also asked by anon-252065.
    • Photo: Delma Childers

      Delma Childers answered on 24 Apr 2020:

      I would say a virus is a microorganism, but we wouldn’t necessarily call it ‘living’ so it’s a bit distinct from bacteria, fungi, and parasites. We don’t consider a virus as ‘alive’ because they don’t have all of the machinery they need to make more copies of themselves. To get past this challenge, they infect living cells and hijack the cell’s machinery to make more copies of the virus. The common cold, influenza, and now COVID-19 are viruses you’re probably pretty familiar with, but there are also viruses that infect fungi and bacteria!

    • Photo: Anabel Martinez Lyons

      Anabel Martinez Lyons answered on 24 Apr 2020: last edited 26 Apr 2020 12:35 pm

      Viruses are very small structures (much smaller than our cells) that are composed of 3 main bits: an outer layer (called an envelope), a protein inner layer (called a capsid) and a very small genome (which is the virus’s genetic information) within the capsid on the inside. This genetic information is called RNA (a single stranded genetic code similar to our DNA, which is double stranded). The envelope (outer layer) has spikey proteins that jut out all over it – these proteins are what bind to the surface of our cells and allow entry into the cell. Once inside, viruses travel to the nucleus of our cells (which is the compartment where all of the cell’s DNA is kept), and insert their genetic information (RNA) inside. From there, what happens is that we (our cells) then replicate our normal DNA PLUS the viral RNA and eventually will use that information to create both normal AND viral proteins. The viral proteins form together to create many more viruses, and these viruses go on to burst out of the cell (which kills it) and infect neighbouring cells to begin the process all over again.

    • Photo: Ozge Ozkaya

      Ozge Ozkaya answered on 24 Apr 2020:

      Little pieces of DNA or RNA encapsulated in a coat! 🙂

    • Photo: Donna MacCallum

      Donna MacCallum answered on 26 Apr 2020:

      Great question… they’re not living things, but they are able to hijack cells to make more viruses.

      They do have a genome (either DNA or RNA) and they have a virus coat that lets them attach to cells that they can infect. The genome is used by the cell to make virus proteins that allow more viruses to be assembled and released.

      Pretty impressive for a non-living thing!

Comments

  • Photo: Cameron

    Cameron commented on :

    Viruses are small pieces of genetic information that are protected by proteins (a capsid) and sometimes an envelope (which is made of fat). They come in all shapes and sizes, some have an envelope with spikes, some have no envelope at all. Viruses can go into cells and cause disease, but only in certain organisms.

    They cause disease by taking over cells and forcing them to make more virus. This virus either tires out the cell by forcing it to produce more copies, or makes it burst open which can kill the cell. These viruses which escape can then effect neighbouring cells.

    There are over 3 million different viruses, but only a small amount of these can infect humans. The rest either infect plants, bacteria or fungi. We even have started using viruses to treat human diseases like cancer!