Microorganisms

 

I find this topic absolutely fascinating and I always have. Nothing to do with the current situation, although has stimulated my interest of course.

Viruses and Bacteria.

Hundreds of millions of viruses can be found in one square meter, the same space holds tens of millions of bacteria. They are all around us all the time except in perfectly sterile environments, which require very special conditions as in laboratories and so on and even then not totally guaranteed.

Our skin is also covered in bacteria, most of which are harmless.

Bacteria are massive compared to viruses and can be seen through a microscope. To see a virus requires a powerful electron microscope.

Bacteria are alive in that they have all the key elements of life which are:

Homeostasis: regulation of the internal environment to maintain a constant state.

Organization: being structurally composed of one or more cells – the basic units of life.

Metabolism: transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce other phenomena associated with life.

Reproduction: the ability to produce new individual organisms, either asexually from a single parent organism or sexually from two parent organisms.

Viruses have none of these key process and are, thus, non-living. They are like machines with only one function, to replicate themselves.

Viruses can only reproduce inside a living cell using the host cells RNA/DNA to replicate itself. The host cell can be either animal or vegetable depending on the species of virus. They are parasites.

There are viruses that only attack bacteria known as bacteriophages.

Bacteria can live anywhere, inside and outside a living organism, viruses can only 'live' inside a living cell.

About 99% of all bacteria are totally harmless to us, and many are essential to our life. About 7 to 10% of our body weight is composed of bacteria, many in the digestive system, without which we could not digest food.

ALL viruses are potentially dangerous to us.

Bacterial infection is usually organ-specific, while virus infection is usually systemic, affecting the whole organism.

Bacteria can be destroyed with antibiotics, although the emergence of antibiotic-resistant bacteria through evolution has reduced the use of antibiotics. Viruses also evolve and very swiftly.

Viruses can only be destroyed by our immune system. There is no secure way to destroy viruses other than to immunize with a weakened version of the virus, thereby triggering an immune system response so the system 'learns' how to deal with the virus, hopefully. If an individual survives a virus infection their immune system has 'learned' how to deal with it although, again, this is not an absolute guarantee.

The origin of viruses is debated. They probably appeared very early in the emergence of life on the Earth.

I find viruses fascinating. A very simple and highly efficient 'machine'.