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I slept through biology class, could you explain how that's not also true for virii, given that they are also not "alive"?
by hodwik 10y ago
I slept through biology class, could you explain how that's not also true for virii, given that they are also not "alive"?
- danieltillett 10y agoViruses have nucleic acids which are shredded by the high temperatures used to sterilise items (121C). Dry heat will inactivate prions, but you need 200C for 4 hours or more which is more than most plastics can handle.
- hodwik 10y agoThanks. I would mention memes too, but I think 121C would shred their host as well. Edit: Actually, Carl Sagan wrote his memes in metal (and shot them into the universe) so I take that back.
- danieltillett 10y agoYes being autoclaved (this is what the process of sterilising with steam at 121C is called) is not the most pleasant way to die.
- logfromblammo 10y agoViruses have two main components. The first is the delivery package. This is the element that is capable of delivering a payload into the interior of a cell. The second is the genetic code that hijacks a cell's normal functioning to produce more viruses. Viruses have a genetic component, either RNA or DNA, which contain instructions for building their viral envelopes. The genetic material is as vulnerable to damage as cellular DNA. Prions are a single component. They are proteins with the same amino acid sequence as a protein normally produced by an organism. Except they have been misfolded. The geometry of the misfolded protein is such that it becomes a catalyst to reproduce the same misfolding error. There are no "brains" in them. They can arise entirely accidentally. They're a bit like the ice-nine from Vonnegut's _Cat's Cradle_, in which a crystal of a novel form of solid water that melts at a higher temperature can recruit liquid water to grow the crystal without limit. Each individual prion can misfold any number of same-sequenced amino acid chains. And like the ice-nine, which melted at a temperature above human body temperature, the prion may be able to survive through more extreme conditions than other forms of the protein. In the best case scenario, the prion does little more than cause a deficiency of the normally-folded protein forms in the body. In the worst-case scenario, it poisons some other process within the body in its misfolded form.
- hodwik 10y agoGot it. It's like honey crystals. They force other crystals to be of the same size and shape. (That's why creamed honey producers put a "starter" crystal in, which is tiny, that forces the honey to produce other tiny crystals.)
- josu 10y agoMy understanding is that the fact that viruses are not alive is more of a convention, similar to Pluto not being a planet. This is more of a question than a statement, I would love it if somebody with some knowledge on the matter could chime in.
- ctdonath 10y agoBacteria can do things on their own (say, swim in water). Viruses can't do anything without a host's reproduction engine (like a program which can't do anything without a computer to run on). Prions are misshapen proteins which tend to damage other proteins such that the result is the same misshapen, and thus duplicating, form.
- PascalsMugger 10y agoI think what was meant is that on the grand scale of "aliveness" viruses are more alive than prions. Viruses have DNA, they actively seek out host cells to hijack so they can reproduce, etc. Prions are much simpler and aren't alive at all. They're just accidentally self-reproducing patterns, basically. They don't have DNA, they don't make any specific effort to reproduce, they just "happen" from weirdly broken matter bumping together.
- hodwik 10y agoViruses don't make any specific effort to reproduce, they too are just accidentally self-reproducing patterns.
- Ericson2314 10y agolife, species, organism.... all are leaky abstractions. [There's a "species" that spread around the Andes and eventually reached itself on the other side---and could no longer breeed with "itself". Genes could still in theory travel all the way around and back to the discontinuous point, however.] edit: http://i.stack.imgur.com/4VsFW.png http://i.stack.imgur.com/4VsFW.png will make this less confusing, and quite unintentionally :).
- 10y ago
- henrikschroder 10y ago> virii Pet peeve of mine, but it looks like you slept through English class as well. The plural of "virus" in English is "viruses". "virus" in latin is a mass word and has no plural, like "sugar" and "air".
- pluma 10y agoActually isn't virus in Latin u-declension, i.e. the plural form would be virus (long u)?
- goldbrick 10y agoTo add to that, even if virus was to be pluralized in Latin, it would be "viri" not "virii".
- hodwik 10y agoVira, actually. However, virii is the hacker subculture form. This being hackernews... I'm comfortable with my decision.
- hodwik 10y agoYour perscriptivism here seems misguided then, because if virus is a mass word we shouldn't be saying viruses either: just "virus". And anyway, if we absolutely had to express a plurality of virus, it would be "vira". Anyway, this is hackernews. For those of us who grew up in internet hacking communities of the early 90's "virii" was the plural form in the lingua franca. As a descriptivist of great habit, I will continue to use that form.
- henrikschroder 10y agoI am actually a descriptivist myself, but the prescriptive approach usually works best when trying to convince people how to write. Apparently not so in this case. How about this argument then: "virii" is f*ckin ugly? No? Darn. :-)
- henrikschroder 10y ago