What is a Virus?
Viruses are alive–although that s a topic of great debate; they simply re merely packets of genetically altered genetic material. Some carry this genetic code in single infected strands of DNA, others in multiples of DNA or in whole chromosome strands. However, they all utilize those same instructions as a blueprint for infecting healthy or host cells. For instance, a virus that infects humans is a form of the herpes simplex virus. Similarly, a virus that infects animals is a form of the pox virus while a virus that infects plants is a form of the swine flu.
Viruses use the genetic material (strands of DNA) from which they are constructed to replicate themselves, spreading their infectious payload to an unlimited number of host cells. There are various methods through which viruses spread from one host cell to another. Some viral replication processes use the host cell’s natural protein machinery to latch onto the target cell, allowing the viral payload to multiply into copies of itself and thus viral replication. The other viral replication process utilizes the ribosome, a highly specific piece of DNA sequence that allows copying to occur when it is paired with the proper transcription unit.
Every virus envelope has a double membrane. The lipid envelope surrounds the virus, acting as both a outer layer and a protective shield. The outer membrane is coated by a thin layer of amino acids called the envelope protein. The inner membrane is made of multiple layers of lipids with each layer designed to protect the membranes of each cell from infection. The lipid envelope is largely responsible for keeping the virus from being killed by the immune system.
The genetic material that is responsible for making up every virus is present within all viruses. However, certain viruses incorporate genetic material in their envelopes that cannot be seen by the eye. This genetic material can be inserted into the genome of an infected cell or virus, which is then passed on to other cells through a process known as transduction. This is often times done by using a piece of DNA known as a insertion virus. The insertions into cells occur frequently in various animal and insect viruses.
The transduction of viruses involves inserting genetic material into the genetic code of a living cell. Once this has been accomplished, the insertion is passed on to the target cell without the chaining of the lipid envelope. The lipid envelope however is essential in order to allow the viral protein coat to attach itself to the cell. If the lipid envelope is not present, the virus will be unable to latch onto the cell.
There are several different types of viruses, including: hepatitis B, herpes, Epstein-Barr, Rubella, tularemia, and rotavirus. The most common forms of these viruses cause infections in animals and insects. A few viruses are even deadly and cause infections in humans. However, the majority of viruses are safe to humans. In fact, they are responsible for killing millions of people every year.