[Quantum_Vaccuum (OP)]

If Viruses Aren't Alive Bacteria how exactly do they reproduce, and spread so quikly from person to person, airborne or not. My science teacher said that they link onto the other protiens and "take over" them, so that explains the reproducing, but the spreading from one person to another is still unsure for me.

[kdlynn]

viruses aren't bacteria at all, are they?

[another_someone]

Kadie is right, viruses and bacteria are two completely different things.

The way viruses spread varies from virus to virus, just as it varies from bacteria to bacteria.  How viruses can spread depends on how easily viruses are killed, and on the exact mechanism they use to enter a cell.  Some viruses, such as influenza, are quite good survivors, and will easily spread from person to person (e.g. if an infected person touches a door handle, then an uninfected person touches the same door handle, they can get the virus on their hands, and then if they rub their eyes with their hand, the virus can enter the body through the tear ducts).  By comparison, HIV is very difficult to catch (which is lucky, because it is generally a more dangerous disease when it is caught), and the HIV virus will not survive at all outside of the human body, so you actually need body fluids (semen or blood) to pass between people in order to pass on the virus.

Once in the body, the virus will attach itself to the outside of a cell, and then transport itself into the cell, and will then hijack the cells means of reproducing itself in order to instruct the cell to reproduce lots and lots of copies of the virus, and then when the cell is full of new viruses, the cell will burst and the new viruses will then try and find cells of their own to hijack, and the cycle continues.

[Quantum_Vaccuum (OP)]

If Viruses Aren't Alive Bacteria

here i meant that they aren't alive OR bacteria, and how long can most bacteria live outside of a body, (the average bacteria)

[another_someone]

here i meant that they aren't alive OR bacteria, and how long can most bacteria live outside of a body, (the average bacteria)

Depends on the bacteria, but most bacteria spend their entire life outside of the human body.  It is only a very small fraction of all the bacteria in the world that are known to cause disease - most bacteria live their own lives outside any body, and without them all life would cease (since they are often the only way some matter can be converted into a form that can be digested by plants or animals, and in other cases, they simply help recycle dead plant and animal tissue).  Even some of the bacteria that are within us are useful to us, not least in helping us digest our food (which is why after being treated with broad spectrum antibiotics, which will kill all the bacteria in your guts, you normally have an upset stomach until the bacteria recolonise your guts).