Share
Explore BrainMass

Viruses

Viruses, in a biological sense, are infectious agents which are able to reproduce once they are inside the host cells of another organism. In terms of size viruses are extremely small and in some cases, a light microscope cannot detect these agents.

Unlike other organisms, such as animals and plants, viruses lack a cellular structure and instead rely on the structure of the cells of the host organism which they attack. It has been contested throughout past discussions and among the literature whether viruses can be thought of as a life form. There still remains no absolute consensus, but it is often thought that viruses are not alive. On the one hand they do have their own genetic material (either DNA or RNA) and they are capable of reproducing. However, all cellular functions, such as metabolism and reproduction even, cannot be carried out by viruses on their own as they lack the appropriate cellular machinery. Thus, they use the machinery provided by the host cells. 

The diagram below, referenced as Figure 1, provides an example of a viral vector and its basic structure. The basic elements of a viral vector are:

  1. The genetic material, which can be seen in Figure 1 as a long, yellow coloured molecule.
  2. A protein coat.
  3. An envelope of lipids, which in the diagram below is referenced as an envelope of glycoproteins. These lipids are always on the outside of the cell. This is not present in all cases.

Figure 1. This image is representative of a viral agent, specifically that of the Hepatitis C Virus. This diagram depicts the overall structure of the virus1.

Viruses are capable of spreading in many different ways, which makes them very dangerous. Furthermore, viruses can infect all organisms and can even spread from one species to a different species. 

 

 

References:
1. Wikimedia Commons. (2008).Hepatitis C Virus. Retrieved from http://en.wikipedia.org/wiki/File:HCV_structure.png
Title Image Credit: openclipart.org 

vaccine development

vaccine development for diseases caused by protists (e.g. malaria, chagas' disease)has been much less successful than for bacterial or viral diseases. discuss at least one biological and one geographical reason for this fact. please include resources. thank you

Viral Replication - Six Events

List the six events that occur in viral replication. For each event, include a paragraph describing what occurs during that particular stage.

Microbes that are difficult to control

I need a short topic of discussion for the following item listed below. Which pathogen is more difficult to control: A pathogenic virus or bacteria? This course has introduced a variety of disease organisms. Pathogenic bacteria have claimed many lives in third world countries. Bacteria have been controlled through antibiot

Sides effects of vaccinations

I am in need of a short paragraph to help me with an answer to this discussion topic. The immune system is an amazing instrument of the human body. The value of a healthy immune system means that the body will fight off disease. Vaccination manipulates an important component of the immune system by selectively building immuni

Mycobacterium and plasmodium

I need to address in more detail this pathogen, Mycobacterium or a second microbe, and I am trying to respond to the question presented in regards to two microbes. Also, could you please provide a reference page? Thank you.

Pathogenicity and Immunology; Host resistance and the immune (SLP 4)

Discuss the role of the immune system in protecting the body from the pathogenic and non-pathogenic microbes selected in Module 1 and 2. How would the body's immune response differ if it was previously exposed to the same pathogen 2 years ago as compared to an initial exposure?

Pathogenicity and Immunology; Host resistance and the immune (CASE4)

In this module you have learned of the importance of the immune system in protecting against disease. For the Module 4 case assignment you will investigate the virus HIV and its effect on the human immune system, as well as important topics in infectious disease in general. It is estimated that over 34 million people globally

Physical and chemical control of growth and viability (SLP)

Discuss the metabolic requirements for growth of each microbe and select one antibiotic (bacteria), antiviral (virus) or anti-fungal (fungi) agent, depending on the pathogens that you selected. Discuss the mechanism of action by which the drug kills or inhibits the growth of the selected pathogen. Be sure to look on your libra

Physical and chemical control of growth and viability (CASE)

In the module 3 case assignment you will explore bacterial growth and methods used to measure the growth of microbes. After you have read the information in the background readings and home page you should prepare a paper addressing the topics below: 1. Discuss the four phases of the bacterial growth curve. 2. Explain two

Antibiotic Resistance and Methicillin (MRSA)

Methicillin resistant Staphylococcus aureus (MRSA) has become a big concern in hospitals throughout the country and the world and have other antibiotic resistant bacterial strains. Part 1 The use, overuse, and abuse of antibiotics is accredited with creating these antibiotic resistant strains. Explain how this relates to n

Edward Jenner Vaccination

Microbiology was a study of living organisms that scientists had some trouble proving to the general public that they even existed. One of the reasons for this was that people could not see the organism. That is, not until the microscope was invented. Antony van Leeuwenhoek (1674 to 1724) was one of the pioneers in the making of

How HIV Infects Helper T Cells

This solution will review the basics of viruses and discuss the process that occurs when a helper T cell is infected by the HIV virus. It includes a glossary to aid in understanding of the technical terms, that occur in a first year introductory college biology class.

Microbiology: mRNA synthesis and ssRNA viruses

1. Why is the synthesis of mRNA a central issue for all viruses? 2. Polio and HIV are both +ssRNA viruses that have very different strategies for replicating their genomes. After the viral genomes enter the cell (ie. post entry), describe the first step involved in replication of each genome. Your description can include a

E.Coli and HIV Similarities and Differences

Pathogens, toxins, infections, and disease; Microbial Applications and Industrial Use; Biotransformations; Microbial decomposition and global recycling Summarize the key differences and similarities between the E.Coli and HIV. Discuss the benefits derived from the subject non-pathogenic microorganisms in the human environm

Physical and chemical control of growth and viability

Present and discuss the differences and similarities in the microbial metabolic and environmental requirements for growth for E Coli and HIV. The focus should be on the effect of environmental factors on growth for both. Growth criteria for E Coli and HIV should also be covered

Disinfection and Sterilization Agents

For each method listed, indicate the mode of action, whether it is sporocidal, common uses, when it should not be used and any special advantages or disadvantages. a. Phenol and penolics: bisphenolics and triclosan b. Alcohols: isoopropanol and ethanol c. Gaseous agents: ethylene oxide gas, chlorine dioxide gas d. Haloge

HIV/AIDS & Hepatitis C

Discuss three ways the Hepatitis C epidemic is similar to the of the HIV/AIDS epidemic and three ways the Hepatitis C epidemic is different than the HIV/AIDS epidemic.

SARS, Outbreak, Travel, Pathogens, Toxins, Infections, and Disease

The World Health Organization has released the following update on the outbreak of SARS. Read the following WHO Update and the information presented from the Armed Forces Institute of Pathology and prepare a characterization of the disease based on the characteristics of infectious diseases and viruses presented. Identify the

Viral Replication and Retroviruses

Describe the process of viral replication; discuss both normal and retroviruses, and comment on the implications of this process for genetic engineering.

Infectious Disease and Risk

There are six characteristics of infectious disease agents which determine whether or not an infectious disease will be transmitted to and infect a host. These characteristics also influence the severity of the disease and even the outcome of the resulting infection. these characteristics are as follows: -Infectivity: The ab

Urinary Tract Infections and Blood Borne Pathogens

Please help with the following problems. 1. How does an active infection occur in the urinary tract? Which factors in the urinary tract predispose humans toward urinary tract infections? 2. Explain the strategies devised by OSHA and the CDC to prevent transmission of blood borne pathogens of infectious diseases.

Autoimmune Disease Immunizations

Lab mice are immunized with a measles vaccine. When the mice are challenged with the measles virus to test the strength of their immunity, the memory cells do not completely prevent replication of the measles virus. The virus undergoes a few rounds of replication before the immune response is observed. You have developed a strai

Microbes with capsules

1. How does an organism with a capsule such as K. pneumoniae, provide the organism with pathogenic abilities to avoid destruction by the host cell? 2. Why are infections of the upper respiratory tract milder as compared to the infections of the lower respiratory tract?

Viruses and Being Alive

Please help answer the following question. Include references. Why are viruses not considered alive? In the explanation, include the criteria that must be met for something to be considered alive.

parasites: organisms that can cause parasitic diseases in the human being

Discuss at least four types of organisms that can cause parasitic diseases in the human being. Explain three laboratory techniques that can be used to identify an intestinal parasitic infection. What are the different routes that pathogenic protozoans can use to enter the host cells? Why were some contact lens sol