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Bacteria, viruses and prions are biological pathogens
What are the essential differences between bacteria, viruses, and prions based on their structure and chemical makeup
Microbiology chapter 13 viruses, prions summary
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Viruses, bacteria, and prions are all quite different, but they all share one commonality: they can all cause disease in humans. All three are also organic, in one way or another. Despite this, only bacteria are properly alive by most definitions. Bacteria are also the most complex, followed by viruses, and then finally, prions.
Bacteria
As mentioned in the introduction, bacteria are the most complex organizations that will be covered in this paper. Bacteria were among the first forms of life to evolve on Earth about 3.5 million years ago. This has allowed them to become one of the most diverse groups of life, from the photosynthetic cyanobacteria, to the parasitic bacteria that infect humans.
Despite being so diverse, bacteria are rather simple in structure compared to eukaryotes such as ourselves. They are prokaryotic, unicellular organisms, meaning that they have neither membrane-bound nuclei nor organelles and exist independently of each other, although they often form colonies. Although bacteria lack organelles in the eukaryotic sense, they do possess ribosomes to manufacture proteins, and a special area called the “nucleoid” that contains the circular chromosome. Surrounding all of this is the cytoplasm, in which a majority of the chemical reactions of a bacterium take place. The cytoplasm itself is then bound by an inner membrane, a rigid cell wall, and in certain species, an outer capsule.
Bacteria, unlike more complex organisms, have multiple different pathways for reproduction. The most commonly used of these paths is binary fission in which the chromosome is duplicated and then the cell simply splits in two. This pathway, however, does not allow for the exchange of genetic information, so bacterial cells ofte...
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...http://amrls.cvm.msu.edu/microbiology/molecular-basis-for-antimicrobial-resistance/acquired-resistance/acquisition-of-antimicrobial-resistance-via-horizontal-gene-transfer>.
4. "Virus." Virus. Encyclopedia Britannica, n.d. Web. 21 Apr. 2014. .
5. "Rhinovirus » Viruses » Pathogen Profile Dictionary." Rhinovirus » Viruses » Pathogen Profile Dictionary. MicrobeWiki, n.d. Web. 21 Apr. 2014. .
6. "HIV/AIDS Fact Sheets | AIDSinfo." AIDSinfo. National Institute of Health, 18 Apr. 2014. Web. 21 Apr. 2014. .
7. "Prions: On the Trail of Killer Proteins." Prions: On the Trail of Killer Proteins. University of Utah, n.d. Web. 21 Apr. 2014. .
Jennifer Ackerman's main focus in her article The Ultimate Social Network, is that of the functions concerning bacteria within humans. Although scientists have had presumptions about humans being proficient in governing their body’s innermost structure, they soon come to recognize the sophistication of our inner space which holds an extensive plethora of bacteria and other microorganisms that lie within each and every one of us. Moreover, scientists' new and emerging view of how the human body operates, and the cause of increasing present-day diseases (i.e. obesity and different autoimmune disorders) are uncovered by analyzing effects of certain microbe species in our bodies. By italicizing on points such as the above, in conjunction with bacteria's genetic variations, and modern computing technology, the author proves that scientists are quickly progressing with the characterization the most prevalent species of microbes, which, in her opinion, is definitely paying off.
Bacteria can function and reproduce as single cells but often combine into multicellular colonies. Bacteria are also surrounded by a cell wall. Archaea differ from bacteria in their genetics and biochemistry. Their cell membranes are made with different material than bacteria.
Guyer, Ruth Levy, Ph.D. “Prions: Puzzling Infectious Proteins” National Institutes of Health Office of Science. 28 July 2006 < science.education.nih.gov/nihHTML/ose/snapshots/multimedia/ritn/prions/prions1.html>.
"HIV/AIDS Basics." AIDS.gov. U.S. Department of Health & Human Services. Web. 18 Jan. 2012. . Regularly maintained by the U.S. Dept. of HHS
PrP can occur in two forms- a normal cellular prion protein known as PrPc and a pathogenic misfolded conformer known as PrPsc. The abnormal PrPsc differs from the normal prion protein PrPc in both secondary and tertiary structure. PrPsc is principally rich in Beta sheet contents but PrPc is principally rich in alpha helical contents. Due to this difference of between the isoforms, prions are extremely resistant to certain decontamination systems. The Two tables below outline both human and animal diseases (2).
Prions are pathogens, and cause infections, like viruses. Prions cause many neurodegenerative diseases, but are made up of harmless proteins found in mammals and birds. The proteins are not in their normal form though, and once they enter the human brain, can cause severe brain infections. One thing that makes them different from viruses, is the lack of nucleic acids, which means they have no genetic code. Once in the brain, they make normal proteins turn into abnormal ones, which then multiply, causing severe infection. Soon, holes appear in the brain that can only be treated by incineration. An example of a disease caused by a prion would be the Mad Cow Disease, or the human equivalent Creutzfeldt–Jakob disease. Prions are very dangerous. While some people can confuse prions and viruses, there are some ways to tell the difference.
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Despite the accomplishments, water-borne diseases remain an issue of concern. “From 1971 to 1988 there were 564 infectious outbreaks in the United States involving nearly 140,000 people.” Bacteria are microorganisms that are of the kingdom Prokaryotae. When certain bacteria appear in places where they do not normally reside, they can cause illness.
Compounding these exceptionally troubling numbers is a significant population with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). Again estimates vary, but the United Nations projects the national prevalence rate to be 4.5 percent of the population. Other estimates place the rate as high as 12 percent in the urban population and 5 percent in rural regions. As a small “win”, the infection rate for HIV/AIDS has recently shifted downward due to significant UNAIDS/WHO efforts (Haiti – Health).
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
Dr. Patricia Stock’s particular area of study does not include the biochemical investigation of their composition to find their chemical usefulness or the cure for cancer or anything of that nature. Her aim is simply to research and study the mutuality between the bacteria and their nematode hosts in order to better understand their evolutionary biology and pathogenesis.
Bacteria are single celled microbes. Bacteria reproduce by binary fission. In this process, the bacterium, which is a single cell, divides into two identical daughter cells. Binary
In United States, the HIV epidemic reached its peak in the 1980s when the number of infected reached 130,000 people per year. Infected women ...
Microbes are everywhere in the biosphere, and their presence invariably affects the environment in which they grow. The effects