Getting Technical
CHARLES NICOLSON
Charles Nicolson has a physics and chemistry degree from Natal University which he subsequently put to
good use by applying speciality chemicals in mining and industrial processes where water is a major factor.
This created an enduring interest in water technology, a passion that expanded to the HVAC industry
in 1984 when he joined BHT Water Treatment. Since then, water technology in HVAC water circuits has
continued to be an abiding interest.
VIRUSES. WHAT ARE THEY?
By Charles Nicolson
This article about viruses was written in February this year before the
Corona ID -19 virus which had started in China exploded into the
current global pandemic.
In recent years nothing has grabbed the attention of the
populace world-wide as much as the escalating mortality toll
caused by the onslaught of this virus as it continued to spread.
News media have concentrated intensely on reporting infections,
rising numbers of deaths (and recoveries) and the dedication of
courageous and heroic medical and health workers. However,
understandably there has been virtually no information as yet
regarding the basic question: what is a virus?
According to microbiologists, viruses are by far the most
abundant biological entities on earth, outnumbering the total of
all the others added together. They infect all types and sizes of
cellular life including animals, plants bacteria and fungi. Viruses
are considered by some microbiologists to be a life form because
they contain and carry genetic material, reproduce, and undergo
alterations and changes to their composition and characteristics
along lines similar to the concept of natural selection, although
they lack key characteristics such as cell structures that are
generally considered necessary in any entity for it to be defined
as a ‘life form’. Because they possess some but not all of these
attributes and properties, viruses have been described as
‘organisms at the edge of life’.
In a previous Getting Technical article there was reference to
a report in the Star newspaper that the existence of the smallest
sub-nuclear particle, until then proposed in theory under the
name of the ‘Higgs Boson’, had recently been proven in an
experiment at the CERN complex in Europe. The mass of the
Higgs Boson tends to zero so it is regarded as representing a state
of transition between energy and mass or, in other words, ‘an
entity at edge of mass’ which could be viewed as analogous to a
virus being ‘at the edge of life’.
Viruses are smaller and simpler than bacteria. By themselves
they are inert and as such are not alive. They are just wherever
University of Pennsylvania
they are and not doing anything or reacting with any other
entities or substances. However, when they come into contact
with any suitable type of host they tend to ‘spring into life’ by
hijacking genetic substances inside host cells and combining with
these substances in ways which allow the viruses to reproduce
themselves rapidly.
As already mentioned, viruses are small. In general, viruses
are about one hundredth of the average size of bacteria, which
measure out at approximately one micron. At a hundred times
smaller, viruses are therefore approximately one hundredth of
one millionth of a metre – which explains why viruses are not
visible under conventional optical microscopes. It was not until
the first electron microscopes became operational during the
early 1940s that the first visual images of viruses were able to
be observed.
Figure 1: Electron microphotograph
of multiple bacteriophages attached
to the wall of a bacterial cell.
The caption on Figure 1 above refers to the viruses attached to
the bacterial cell wall as ‘bacteriophages’. This is a typical example
of technical nomenclature used in microbiology which can get
very complex and confusing. Bacteriophages are types of viruses
which almost exclusively attack only specific species of bacterial
cells. To avoid using too many technical terms in this article, all
viral types will come under the term ‘virus’.
www.hvacronline.co.za RACA Journal I August 2020 37