Reference no: EM132794676

Viruses are small, non-cellular structures of nucleic acid and protein. Several types of viruses attack bacterial and are known as bacteriophages or phages for short. One of the viruses that attacks the bacterium Escherichia coli is the bacteriophage T2. This virus contains only protein and DNA. The DNA forms the central core of the virus and the protein surrounds the core. The protein coat of a virus is called the capsid. Phages infect bacteria by absorbing to the cell walls and infecting the genetic material into the bacteria almost like a syringe. The genetic material takes over the cell metabolism or hijacks the cell and orders the production of viral parts. The viral parts are assembled into complete new viruses called virions. Eventually the bacterial cell is ruptured via cytolysis and the new viruses are released.

Experiments that clearly associated DNA and heredity were performed by Alfred Hershey and Martha Chase in 1952. They wanted to prove that DNA was the material that passed on genetic traits not protein. They explored the genetic properties of DNA using bacterial viruses (bacteriophages). The chemical make-up of protein and experiment. DNA contains phosphorus and proteins do not. Proteins usually contain sulfur, and DNA does not. By incorporating radioactive phosphorus into the viral DNA and sulfur atoms into the viral protein, Hershey and Chase could distinguish definitively between the protein and the DNA of the phage. This technique is called radioactive labeling. They could also determine whether either or both were injected into the bacterial cell during the course of infection. When bacteriophage labeled with 32 P DNA were allowed to infect a cell, almost all the labeled phosphorus 32 entered the cell. When the infected cells burst via cytolysis, the new viruses that were produced by the hijacked cell contained the radioactive phosphorus-32.

The opposite occurred when 35S-labeled phage infected a bacterial culture. Almost all the radioactive sulfur remained on the outside of the bacterial cell wall. A small amount of protein did enter the bacterial cell in the course of infection. That this was not involved in the production of new bacteriophage could be demonstrated by repeating the experiment with bacteria stripped of their cell walls. If they were infected with 32P phage DNA free of protein, infectious phage viruses were produced. If the purified 32P was first treated with DNAase, no new phage viruses were produced. Clearly the labeled phosphorus-32 DNA contained all the information necessary to produce new virus particles.

Name of virus. Family and genus of virus?

Is the virus DNA or RNA?

How is the virus spread?

Signs and symptoms of the disease caused by the virus?

What are the treatments and prevention option available?