VIRUSES AND PROKARYOTES

Natalia Alemán

Ms. Villagra

Biology 12th  task #3

November 23, 2017

Viruses and Prokaryotes

        Viruses are infectious particles that live and replicate inside a host organism, they are considered pathogens. Although viruses are microscopic organisms, they are neither prokaryotic nor eukaryotic, since they lack several characteristics of each. Viruses are made of one piece of DNA or RNA, and their purpose is to infect any type of organism. Viruses do not always have a negative impact, they can be found everywhere on Earth, and can sometimes provide “ecosystem services” protecting humans and other species.

        Viruses cannot reproduce on their own, they need a living host cell to be able to elaborate the chemicals needed for them to keep on replicating and spreading. Viruses can inherit DNA mutation.  {1}

The structure of viruses varies for each type; it can be very complex or very simple. But the main structure of a virus is made up of two different parts, a protein coat called a capsid, and a part of a genetic material. Most importantly viruses do not have a cell and are not, in any way, living organisms. They are merely genetic codes that invade any host organism they find. This invasion of the cell is directed by distinct proteins that communicates the cell to create more viruses and spread.  {2}

Viruses can reproduce and enter in a host cell very easily. Although skin is the first layer of protection, if there are breaks in it, a virus can easily invade. A virus can also enter a host through openings like the nose or mouth. {3}

All viruses follow the same steps:

1. “A virus particle attaches to a host cell.
2. The particle releases its genetic instructions into the host cell.
3. The injected genetic material recruits the host cell's enzymes.
4. The enzymes make parts for more new virus particles.
5. The new particles assemble the parts into new viruses.
6. The new particles break free from the host cell.”  (Freudenrich Craig) {3}

        This inevitably leads to viral diseases, human illnesses caused by an infection. They are easily transmitted from person to person. Some examples of viral infections are:

• “Chickenpox
• Flu (influenza)
• Herpes
• Human immunodeficiency virus (HIV/AIDS)
• Human papillomavirus (HPV)
• Infectious mononucleosis
• Mumps, measles and rubella
• Shingles
• Viral gastroenteritis (stomach flu)
• Viral hepatitis
• Viral meningitis
• Viral pneumonia”  {4}

These viral diseases can be treated with different medicines and treatments. But they cannot be attacked through antibiotics, these are specifically used for bacterial diseases and other infections. But, many viral diseases like the “common cold” are usually resolved fairly quickly.

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