A virus is a collection of genes, protein molecules and infectious particles that live by invading living cells. A virus can be single celled or multiply into millions of copies. There are two different kinds of viruses: arboviruses and retroviruses. A virus can hide in a protein molecule or DNA, causing the cells it invades to become abnormal and cause illness.
A virus is typically composed of a central piece of genetic material called the RNA or DNA, surrounded by a thin layer of viral protein, called the viral envelope. Occasionally, the viral envelope also contains a second spikey coat known as the envelope. Viruses are able to latch onto host cells through a variety of means. Some viruses are controlled by the host cell’s immune response and others by chemical modification to the host cell’s DNA.
Most viruses replicate themselves by breaking apart a virus-host cell and inserting their genetic RNA into the broken DNA of the host cell. This RNA then causes the cell to duplicate its own protein on its own, ultimately forming a virus. When a virus replicates itself, it uses up all the DNA and protein on the infected cell. It leaves nothing but a dormant virus, ready to reproduce again at some later time.
When a virus divides uncontrollably, it usually destroys its host by releasing its viral protein into the air. If enough of the virus spreads throughout the body, it can control the activities of other cells by manipulating their DNA. This means a virus can multiply in an individual’s body and control its own cells; the result can be a life threatening condition called AIDS. In order to avoid contracting HIV, a person should always avoid sexual contact with other people.
The HIV virus has not only affected the development of HIV itself, but also the ability of other cells to divide and reproduce themselves. This makes it extremely difficult to fight against, as no new cells can divide. Because of this, it is impossible to permanently eliminate a virus that has already infected living cells. However, there are ways to prevent the virus from infecting healthy cells. A good example of this is vaccination, as it can prevent infection from a wide variety of bacteria.
Some viruses hide in a complex viral envelope. These envelopes are made up of DNA, RNA, and transcription factors. When the DNA is inserted into a host cell, the transcription factor produces the viral protein. This virus then travels through the body, duplicating itself as it goes. There is currently no known cure for complex viruses, which makes prevention and treatment of the virus extremely difficult.