H1N1 is an orthomyxovirus, a type of minus-stranded RNA virus that infects the r
ID: 170205 • Letter: H
Question
H1N1 is an orthomyxovirus, a type of minus-stranded RNA virus that infects the respiratory and pulmonary systems of humans. a. Describe the structure of a minus RNA virus when it is outside of a host cell. b. Explain the life-cycle of a minus RNA virus. How does it infect cells, replicate, and leave the cell? Be specific! c. H1N1 infection is not often fatal but is more deadly to younger people than the elderly. You are working in a virology lab, hoping to devise a treatment for people who are infected with H1N1. Propose and explain a molecular way in which you might try to do this. (There are several possible answers to this question but keep in mind that you are looking for a treatment, not a preventative.) 2. Ricin is a protein that can be isolated from castor beans. In pure form, ricin is extremely poisonous when inhaled or injected. Ricin can bind to eukaryotic ribosomal subunits and cleave them, making them inactive and ultimately preventing their action. a. What is the general structure of a ribosome? b. What biological process is inhibited by ricin if ribosomes are destroyed? c. Describe the steps of the process named in part b from initiation to termination. Ciprofloxacin (Cipro) is a wide-spectrum antibiotic that inhibits bacterial forms of topoisomerase. It was widely known 10 years ago as the antibiotic that was being stockpiled in case of a bioterrorism attack with anthrax. Now it is prescribed for severe, but common, bacterial infections on a fairly regular basis. a. What is topoisomerase and what is its function in DNA replication? b. If a patient with a bacterial infection is treated Cipro what will be the likely effects on the bacterial infection? In your response, cover all (1) the specific effects on the bacterial DNA (and reasons for those effects), (2) the effects on the bacteria as a whole, and (3) the effects on the patient's infection.Explanation / Answer
1.A)The influenza virion (as the infectious particle is called) is roughly spherical. It is an enveloped virus – that is, the outer layer is a lipid membrane which is taken from the host cell in which the virus multiplies. Inserted into the lipid membrane are ‘spikes’, which are proteins – actually glycoproteins, because they consist of protein linked to sugars – known as HA (hemagglutinin) and NA (neuraminidase). Beneath the lipid membrane is a viral protein called M1, or matrix protein. This protein, which forms a shell, gives strength and rigidity to the lipid envelope
B) The cell engulfs the virus.The virus is able to pierce the bubble of cell membrane that encloses it and release its RNA cargo into the cell. In the nucleus, copies of the viral RNA are made.Viral messenger RNA causes the cell to make viral proteins.These proteins and RNA migrate to the cell's surface where they are assembled into new virus particles.New virus start budding off from the cell surface.
C)Two antiviral agents, zanamivir (Relenza) and oseltamivir (Tamiflu), have been reported to help prevent or reduce the effects of swine flu if taken within 48 hours of the onset of symptoms.But Vaccination is the best way to prevent or reduce the chances of becoming infected with influenza viruses.Treatment is largely supportive and consists of bedrest, increased fluid consumption, cough suppressants, and antipyretics and analgesics (eg, acetaminophen, nonsteroidal anti-inflammatory drugs) for fever and myalgias
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