ISSUE 04 | APRIL 2020
Are viruses alive?
Viruses rely on the cells of other
organisms to survive and
reproduce because they can't
capture or store energy
themselves. In other words, they
cannot function outside a host
organism, which is why they are
often regarded as non-living.
Outside a cell, a virus it wraps
itself up into an independent
particle called a virion. The virion
can "survive" in the environment
for a certain period of time,
which means it remains
structurally intact and is capable
of infecting a suitable organism
if one comes into contact.
When a virion attaches to a
suitable host cell, this depends
on the protein molecules on the
surfaces of the virion and the
cell; It is able to penetrate the
cell. Once inside, the virus
"hacks" the cell to produce more
virions. The virions make their
way out of the cell, usually
destroying it in the process, and
then head off to infect more
cells.
BIKERS CLUB ® MAGAZINE | PAGE 24
Does this "life cycle" make viruses
alive? It's a philosophical question,
but we can agree that either way
they can have a huge impact on
living things.
What are viruses
made of?
At the core of a virus, a particle is a
genome, the long molecule made
of DNA or RNA that contains the
genetic instructions for
reproducing the virus. This is
wrapped up in a coat made of
protein molecules called a capsid,
which protects the genetic
material.
Some viruses also have an outer
envelope made of lipids, which are
fatty organic molecules. The
coronavirus that causes COVID-19
is one of these "enveloped" viruses.
Soap can dissolve this fatty
envelope, leading to the
destruction of the whole virus
particle. That's one reason washing
your hands with soap is so
effective!
What do viruses
attack?
Viruses are like predators with
specific prey they can recognise
and attack. Viruses that do not
recognise our cells will be
harmless, and some others will
infect us but will have no
consequences for our health.
Many animal and plant species
have their own viruses. Cats have
the feline immunodeficiency virus
or FIV, a cat version of HIV, which
causes AIDS in humans. Bats host
many different kinds of
coronavirus, one of which is
believed to be the source of the
novel coronavirus that cause
COVID-19.
Bacteria also have unique viruses
called bacteriophages, which in
some cases can be used to fight
bacterial infections.
Viruses can mutate and combine
with one another. Sometimes, as
in the case of COVID-19, that
means they can switch species.