The Structure and Function of a Virus

The first person to observer viruses in a lab setting was a physician by the name of Robert Buist. He conducted an experiment where he viewed cells taken from skin eruptions of small pox patients. He noticed there were particles that were not part of the original cell, they were completely independent. He dubbed these particles "inclusion bodies." The inclusion bodies will later become known as viruses.

Scientists are unsure whether or not viruses are living organisms or simply assemblies of molecules. They seem to straddle the definition of life with some functions that can be attributed to an organism and others not. One person described a virus being as alive as a rock. They are composed only as genetic material. Some scientists say they are alive while others say they aren't.

Viruses cannot be seen with the naked eye because they are smaller than the wave length of light. They can't be seen with a normal microscope, an electron microscope is needed. Electron microscopes direct a beam of electrons at an object rather than a beam of light. The beam of electrons is small enough that it can magnify the virus enough times for the human eye.

Viruses assume a variety of shapes. There are helical viruses, which obviously have a helical structure, polyhedral viruses, many sided, enveloped viruses, surrounded by an envelope, and binal viruses that are irregularly shaped with complex structures.

 A virus have to infect a host in order to reproduce. Some viruses release material into a host cell while others simply trick the cell. In order to trick a cell, the virus will attach itself to surface molecules and are carried into the cell. Both types of invasion involve penetrating the cell's membrane. A virus is rogue DNA, this means that once it is inside of the cell it is able to take over the host cell and use its own machinery to replicate itself.