According to Black, a prokaryotic cell is defined as lacking a nucleus and other membrane-enclosed structures. An example of a prokaryotic cell is a bacterium. “Most bacteria on this planet, both in the environment and living in and on humans, are member of the domain Bacteria.” There are many different structures within the bacteria cells, but the focus in this case will be on the ribosome. (Black, 2008)

A bacillus, which is a rodlike bacterium, contains many different cell structures. It has a flagellum, which consists of fibrils and flagellin, a cell wall, that maintains the characteristic shape of the cell and prevents the bursting of the cell, and pili, that acts in an attachment or conjugation nature. The focus of this paper, the organelle ribosome, is made up of protein and RNA, and are spherical in shape. In most cases, especially with the bacteria, are clustered in polyribosome chains. To determine the size of a ribosome, one must measure how fast or slow they move toward the bottom of a tube in a centrifuge while it is being spun. This is know as the sedimentation rate of a ribosome. These sedimentation rates are measured in Svedberg units (S) and bacterial ribosomes measure at a rate of 70S, and their subunits somewhere between 30S and 50S. (Black, 2008)

It is important to know that ribosomes present in prokaryotes are slightly different than those found in eukaryote. One difference is their size. This is important when treating the bacteria with antibiotics. Antibiotics are made specifically to bind to specific size ribosomes. For example, streptomycin will attach to a 70S ribosome in order halt the protein synthesis within. Because the eurkaryotic ribosomes have larger Svedberg units, they are not affected, but the bacterial ribosomes are allowed to be killed off, leaving behind the healthy ribosomes needed for protein synthesis with the host cell. (Black, 2008) (Biology: Ribosomes, 2014)

The functions of the bacterial ribosomes is similar to the eukaryotic in the sense that they both are the site of protein synthesis. In the prokaryotic ribosome, translation of RNA and decoding take place in the small subunit. The larger subunits are designated as the site of the formation of peptide bonds. Overall, there are 10,000 bacterial ribosomes which float freely within the cytoplasm. They account for about 50% of proteins in the molecule and are 30% of the overall weight of the cell. (Wassenaar, 2013)

There are good and bad bacteria within human bodies. They can produce different toxins, some which have no effect on people, and others can cause sickness or even death. This is vital in understanding pathogenic bacteria and how they affect even the smallest cell structures like ribosomes. We discussed earlier that antibiotics are specially designed to be the exact size of a pathogenic bacteria in order to completely kill the disease the bacteria bring, but leave the eukaryotic ribosomes intact and unharmed. However, before the antibiotic can be prescribed, there must be an infection present. “The resulting infection is a process with three possible outcomes: the host wins and the bacteria are removed (possibly with the help of medication) so that the host can recover; the bacteria win the ultimate battle and kill their host (sad but true: bacterial infections are a major cause of death especially for children and elderly people); or an equilibrium is reached in which host and bacteria live involuntarily together and damage is minimized.” (Wassenaar, 2013)

Ribosomes are key in fighting off disease and infection caused by bacteria. The cell structures in general each serve a vital purpose that enable humans to do their best internally to stave off diseases. Researchers having a better understanding of pathogenic bacteria allow better treatment and prevention of potentially fatal diseases.

References

Black, J. (2008). Characteristics of Prokaryotic and Eukaryotic Cells. In Microbiology:

Principles and explorations (8th ed., pp. 81-88). Hoboken, New Jersey: John Wiley &

Sons.

Wassenaar, T.M. (2013, June 6). Bacterial pathogenicity. Retrieved March 31, 2015, from http://

www.bacteriamuseum.org/index.php/main-exhibits/pathogenic-bacteria/pathogenicity

Ribosomes. (2014). Retrieved April 1, 2015, from http://biology.tutorvista.com/

animal-and-plant-cells/ribosomes.html