Viruses, Bacteria, and Prions are all small organisms that can do incredible damage, but also help in other ways too. Each one has a different structural make up, and infects or helps humans in many different ways. In this paper ill talk about the structures of each, the reproductive methods, the ways that each infects humans or other organisms, and what other structures and organisms can be infected by each.
First off we will talk about the structural make up of each. Viruses each have a very specific structure, that doesn’t vary all to much from virus to virus. Each one has three main parts; The outer capsid, which is comprised of protein subunits encases the nucleic acid, and then there is a spike or spikes that protrude and are used for infecting hosts. Bacteria also have three main structural regions. Each on has appendages in the form of flagella or pili, and these are used for movement. Each also has a cell envelope consisting of a capsule, cell wall, and a plasma membrane. They also have the inner cytoplasm region which contains the DNA, Ribosomes and other organelles. Prions do not have a certain form that is known for sure, but their structure is caused by the folding of acids in the protein. Leading to a miss shaped protein unit that causes infection and spreads to other proteins. Prions, unlike viruses and bacteria, actually do not have nucleic acid, therefore cannot be treated the same way.
Each of these small structures, must like every other organism, reproduce. The only wa y to ensure the continuation of life, if that is what it can be called in these organisms, is to reproduce. Viruses reproduce by infecting specific host cells. The spike fits into only certain types of cells in a lock and key manner, which is...
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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>.
In the subsequent essay I will discuss and explain the relative function of the Prion protein. The Prion protein, also known as PrPC, ‘’is a membrane-anchored protein with two N-glycosylation sites and, although it is highly expressed in the nervous tissues, its physiological functions have yet to be well established’’ (Coordination Chemistry Reviews). PrPC/PrP is found in healthy brains in this form, and consists of 250 Amino Acids, yet after a simple misfolding in the secondary structure; this can alienate the PrP and forms PrPsc, which is the abnormal form of the Prion protein. The infectious agent PrPsc causes neuropathological changes in the brain, and instantly places the individual under the category of someone with the prion disease. PrPsc forms insoluble fibres and thus cannot be studied well using Nuclear Mass Resonance (NMR), and it is also more resistant to protease digestion. Furthermore, ‘’ The transmissible spongiform encephalopathies (TSEs) arise from conversion of the membrane-bound prion protein from PrPC to PrPSc, the latter being the scrapie form. Examples of the TSEs include mad cow disease, chronic wasting disease in deer and elk, scrapie in goats and sheep, and kuru and Creutzfeldt-Jakob disease in humans’’ (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904554/. 2014). The following diagram shows the conversion from PrPc to PrPsc:
The origin of CWD has yet to be determined (Sigurdson & Aguzzi, 2007). The infection was first noted in 1967 at a captive mule deer research facility. In 1978 pathologists recognized the TSE type brain lesions, also that CWD presented as a prion disease by the neuronal perikaryonic vacuoles, the accumulation of aggregated prion protein and prion infectivity in the brain. In the late 1970s and early 1980s the infection w...
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).
Bloodborne pathogens are viruses that deteriorate cells within the body. A virus is a submicroscopic parasitic organism that feeds on cells. Viruses are dependent on cells for their nutrients so the virus survive and reproduce. Every virus consists of either deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). A virus can contain a strand of one or the other, but not both. This RNA or DNA is contained within a protein shell for protection. A virus is a parasite that is dependent upon cells for metabolic and reproductive requirements. By using the cell the virus makes the host very ill by redirecting cellular activity to make more viruses.
Disease and parasitism play a pervasive role in all life. Many of these diseases start with microparasites, which are characterized by their ability to reproduce directly within an individual host. They are also characterized by their small size, short duration of infection, and the production of an immune response in infected and recovered individuals. Microparasites which damage hosts in the course of their association are recognized as pathogens. The level of the interaction and the extent of the resultant damage depends on both the virulence of the pathogen, as well as the host defenses. If the pathogen can overcome the host defenses, the host will be damaged and may not survive. If on the other hand the host defenses overcome the pathogen, the microparasite may fail to establish itself within the host and die.
The prion diseases that Chronic Wasting Disease is related to are Creutzfeldt-Jakobs disease found in humans, bovine spongiform encephalopathy (BSE) in cattle, and scrapies in sheep (3,4). These diseases are grouped together because they share certain characteristics such as long incubation periods, spongiform changes that are associated with neural loss, and cause failure to induce inflammatory responses (Chronic Wasting Disease Alliance).
The virus is primarily spherical shaped and roughly 200nm in size, surrounded by a host-cell derived membrane. Its genome is minus-sense single-stranded RNA 16-18 kb in length. It contains matrix protein inside the envelope, hemagglutinin and neuraminidase, fusion protein, nucleocapsid protein, and L and P proteins to form the RNA polymerase. The host-cell receptors on the outside are hemagglutinin and neuraminidase. The virus is allowed to enter the cell when the hemagglutinin/ neuraminidase glycoproteins fuse with the sialic acid on the surface of the host cell, and the capsid enters the cytoplasm. The infected cells express the fusion protein from the virus, and this links the host cells together to create syncitia.
Pathogens are organisms that are capable of causing diseases in other organisms and are considered to be ubiquitous. They can be found in water, on surfaces, and on or in humans, plants, and animals. Different pathogens have different signs and symptoms, treatment options, ways of transmission, diagnoses, and prognoses. Chickenpox, also known as varicella, and shingles are diseases caused by the same pathogen and have many of the same characteristics, but are also unique in their own ways.
... of bacterial dna buy viruses. When they invade the bcacterial cell they make use of the bacterial protein machinery to produce virions. During process packaging where genetic material is packed into the newly formed virus, bits of bact dna are also included. The new virions carry bact dna into the next cell they infect
Creutzfeldt-Jakob Disease is an uncommon, deteriorating, consistently fatal brain disorder that is caused by prions. The symptoms of CJD are similar of Alzheimer’s but progress much faster. There are three variations of CJD, sporadic, familial, and acquired. All variations affect the brain the same way and have the same result of death. CJD is an untreatable and incurable disease.
Virus- An infectious agent found in virtually all life forms, including humans, animals, plants, fungi, and bacteria. Viruses touch us every day through water, food, physical contact, blood, animals, or even, the air you breathe. All though most are harmless there are some that...
to construct and or maintain the cell membrane. In a microscopic view of the cell membrane we can
Prescott, Harley & Klein (1990) describe bacteria as prokaryotic cells (cells that lack a true membrane enclosed nucleus). Bacteria are both small and simple in structure; they usually are between o.5 and 5cmm yet they have many characteristic shapes and sizes. Some bacteria are circular or oval shaped, they are known as cocci bacteria. Other bacteria are rod-shaped, they are known as bacilli bacteria, and some bacteria are spiral and coil-shaped and it is know as spirilla bacteria.
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