How is a virus transmitted
What is a virus? How do viruses work?
Walter Reed discovered the first human
virus in 1901 but what is a virus
viruses are everywhere from our
surroundings to the very food we eat
we ingest inhale and take in millions of
viruses every second
pretty much all life on Earth has some
kind of virus designed specifically to
infect it including bacteria and even
other viruses viruses are tiny very tiny
you cannot visibly see them in fact they
are so small that if bacteria had eyes
even they wouldn't be able to see all of
them most scientists accept that viruses
are not living but a complex collection
of organic matter that is able to
self-replicate
they mostly consist of a shell made of
protein which inside contains either DNA
or RNA with enzymes for replication and
manipulation of their genetic materials
are you still with me
good let's look more closely a virus is
actually just a piece or strand of
genetic information usually DNA or RNA
which can be single or double stranded
this is the viruses genome it uses this
with the help of various molecular
machines to replicate itself however it
cannot do this alone it must infect some
kind of cell cells are the smallest unit
of life they manufacture proteins
replicate DNA and store resources this
makes them perfect hosts for viruses
armed with its genetic material viruses
are able to infect healthy cells and
convert them into mindless virus
producing robots
the virus uses this outer protein coat
covered in small molecular receptors to
bind and join to the membrane of a cell
this is essential as it is what
determines which cells a virus is able
to infect once joined the virus uses
several complicated biological pathways
in order to force the cell to either
accept its genetic material or take in
the entire virus itself once in the cell
the virus will then begin to use its
molecular Arsenal to hijack the cell's
protein manufacturing systems and DNA
replication mechanism after the virus
has integrated itself into the cells own
DNA the cell will then replicate its DNA
and use it to manufacture proteins
without the cell even knowing it
produces viral protein shells filling
them with virus DNA effectively making
copies of the virus and assembling them
the virus making machine begins to take
over more and more of the cells protein
manufacturing ribosomes churning out
thousands of new viruses which quickly
fill the cell these viruses then cause
tension within the cell and by several
different means bursts from the cell
with the intention of infecting new
hosts for the same purpose
seems like relentless biological
vandalism to me viruses are not all bad
though some are being used to help
strengthen disease resistance in crops
whilst others such as HIV are being used
in curing certain types of cancers but
what is the most remarkable of all is
that many scientists believe some
viruses that infected bacteria billions
of years ago helped form the first cell
nucleus if this is true then all complex
cellular life on Earth descended from a
single virus and his rubbish attempt at
trying to infect a bacterium now that is
remarkable
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