What is Life??

When posed with a difficult question, I do as pretty much every other kid with internet access does: I google it. Since we're also talking about life with respect to viruses and prions, I stuck that in the Google bar as well.

So here's what I found. Viruses are non-cellular infectious particles that consist of DNA or RNA wrapped in a protein shell. Since viruses cannot grow or replicate on their own, they are considered to be "obligate intracellular parasites" and thus, not alive, even though they possess characteristics of both living and non-living things.

Prions, a term coined by Stanley Prusiner to describe a "proteinaceous infectious particle," is like a virus, but it's just the protein shell without the inner DNA/RNA. Essentially, prions can affect animals by attaching their protein parts to replicating cells and taking advantage of them by using their parts to make copies of themselves. Prions have been related in research and characteristics to diseases such as Scrapie in sheep, Bovine Spongiform Encephalopathy (Mad Cow Disease), Kuru (which existed in a tribe of Fore Highlanders in Papua New Guinea because of ritual cannibalism), Creutzfeld-Jacob Disease in humans, and vCJD (a variant of Creutzfeld-Jacob Disease that seems to have come from eating BSE infected cattle in Britain).

But are they considered life?

If we define life by the ability to replicate on one's own, then no. But if some characteristics of living organisms qualify them to be considered "alive," then they are. More important than defining viruses and prions as alive or dead though, is doing research in these fields to determine what impact these organisms have on daily life and what threat they could potentially cause in the future.