Question: viruses (the organic kind)

[IEC]

Originally posted by: Gord

so do bacteria......look at the flu and MRSA......they were pretty well controlled by antibiotics...but then some people think....I'm all better I'll just stop taking my medicine......this is where the virii and bacteria win.....that person won't necessarily be reinfected...but that bacteria or virus inside will adjust and the same antibiotic will be less effective next time until the viru/bacteria is totally immune to that antibiotic....that is why you are told to take the full course of antibiotics.......

Umm... the flu is not a bacterial disease... it's a viral illness and CANNOT be treated by antibiotics. Antibiotics have NO EFFECT on viruses. Common, common, COMMON misconception in the public's view of sicknesses.

 

[sao123]

To understand death from the biological point of view is somewhat interesting.
its hard to explain, but it goes along these lines:
How many of your cells die determines if you die too.
Your body is made completely up of cells, and if you lose too many of one particular specialized cell, or too many in general, the body is no longer able to function & sustain itself and you die.


A virus is some type of genetic material coated with some type of protein recepter. The genetic material may be single strand dna, double strand dna, or rna. The protein is some type of receptor which allows this particular virus to latch onto a reciever receptor on a particular type of cell. (note, most viruses can only infect a small number of different types of cells with common reciever receptors) When the protein bonds to a cell, the virus then injects its genetic material into the cell nucleas, taking over it. The cell replication/division process now makes copies of the virus, instead of making copies of the cell. Eventually the cell bursts (Thus killing the cell in the process.) and the new virii are released to go attack other cells.

So now were back to, how many cells can you lose without dieing.

 

[imhotepmp]

Originally posted by: gururu

Originally posted by: Farvacola
No, Viruses are alive, but they are not classified as organisms. The only requirement they do not meet is the maintaining of homeostasis. In other words, the killing of their host doesn't go agains their nature because they do not follow the same rules organisms follow.

you do realize that there is a nobel prize available to the person that proves a virus is alive.

How would one go about doing that? I think the term 'alive' is really misleading and unimportant. it serves no purpose for the scienific community at large. The fact is the virus will do what its best at doing; surviving. How does it surivive? By finding and infecting a host to create more copies of itself thereby ensuring its survival. A virus has no conscience and its genetic material is compact end efficient. And as such I would expect that virii contain very little non-coding sequences(regions of DNA/RNA that do not code for protein, >90% of human DNA is non-coding).

Do any comparative genomic specialists know if virii any non-coding sequence at all? [begins google search]

I think that virii serve to prove the fact that life will exist in any and all forms possible from something as simple as a virus, to organisms as complicated as us.



Imouthes

 

[gururu]

Originally posted by: imhotepmp


How would one go about doing that?

Imouthes

One wouldn't because viruses are not alive. I guess you can say they 'live' in the same way you might say a joke, or a nickname lives. But they are not a representation of life by any stretch of the word. they are complex molecules that are capable of perpetuating themselves only in a living host (a virus cannot replicate within another virus*); as different as prions are, they are protein molecules capable of the same.

*you can also look at it this way. EVERY living cell including bacteria can be infected by a virus. Yet not a single virus can be infected by another virus.

 

[sao123]

Also noteworthy is that viruses neither consume or expend energy. They are merely complex organic molecules which exist. Any complex structure which can be said to be alive, must consume energy for the life process. Viruses do not meet this criteria.

 

[gururu]

Originally posted by: sao123
Also noteworthy is that viruses neither consume or expend energy. They are merely complex organic molecules which exist. Any complex structure which can be said to be alive, must consume energy for the life process. Viruses do not meet this criteria.

that is a sharp observation. I totally agree.

 

[imhotepmp]

Originally posted by: gururu

Originally posted by: imhotepmp


How would one go about doing that?

Imouthes

One wouldn't because viruses are not alive. I guess you can say they 'live' in the same way you might say a joke, or a nickname lives. But they are not a representation of life by any stretch of the word. they are complex molecules that are capable of perpetuating themselves only in a living host (a virus cannot replicate within another virus*); as different as prions are, they are protein molecules capable of the same.

*you can also look at it this way. EVERY living cell including bacteria can be infected by a virus. Yet not a single virus can be infected by another virus.

It was a rhetorical question...

Imouthes

 

[Gibsons]

imhotep - virii do have introns ("junk DNA." though that's perhaps a misnomer in any case) and splice them. I don't have any sort of number how much of a viral genome is typically non-coding though. I imagine it varies quite a bit.

 

[bigal40]

Originally posted by: Gibsons
imhotep - virii do have introns ("junk DNA." though that's perhaps a misnomer in any case) and splice them. I don't have any sort of number how much of a viral genome is typically non-coding though. I imagine it varies quite a bit.

althoguh virii may have introns they cannot splice them on the own as they do not have spliceosomes nor any other kind of protein for that matter(except for the protein the makes up their capsid,their out covering.) A virus is simply a strand of dna or rna or a double strand of dna or rna, (yes there is double stranded RNA) sorrounded by a protective proteincovering. They may have specialized proteins that can reconize protiens on the outside of theirtarget cells. Virii are not considered alive becuase htye do not have the ability to reproduce on there own. THey have no metabolic stuctures(they cannot make or convert energy to a usable form) with out energy they cannot make any proteins.

A virus inserts it genetic material into a cell which may code for the destruction of the cells dna and then code proteins for its capsid and reproduce its own gentic material. THe cell will burst and the virii are released to infect other cells. that is called the lytic cycle. Some viruses enter the lysogenic cycle when the dna from the virus combines with the dna of the cell and is reproduced with the cell. THe cell continues to live until something causes the viral genetic material to be transcipted and code proteins.

 

[imhotepmp]

Originally posted by: bigal40

Originally posted by: Gibsons
imhotep - virii do have introns ("junk DNA." though that's perhaps a misnomer in any case) and splice them. I don't have any sort of number how much of a viral genome is typically non-coding though. I imagine it varies quite a bit.

althoguh virii may have introns they cannot splice them on the own as they do not have spliceosomes nor any other kind of protein for that matter(except for the protein the makes up their capsid,their out covering.) A virus is simply a strand of dna or rna or a double strand of dna or rna, (yes there is double stranded RNA) sorrounded by a protective proteincovering. They may have specialized proteins that can reconize protiens on the outside of theirtarget cells. Virii are not considered alive becuase htye do not have the ability to reproduce on there own. THey have no metabolic stuctures(they cannot make or convert energy to a usable form) with out energy they cannot make any proteins.

A virus inserts it genetic material into a cell which may code for the destruction of the cells dna and then code proteins for its capsid and reproduce its own gentic material. THe cell will burst and the virii are released to infect other cells. that is called the lytic cycle. Some viruses enter the lysogenic cycle when the dna from the virus combines with the dna of the cell and is reproduced with the cell. THe cell continues to live until something causes the viral genetic material to be transcipted and code proteins.

So if they dont have a spliceosome then that would mean that they use the hosts machinery. Interesting, does that mean viruses may have evolved from eukaryotic cells? Or could it be that the virus acquired it after infection of a eukaryotic cell from a random recombination event?

Imouthes

 

[bigal40]

Originally posted by: imhotepmp

Originally posted by: bigal40

Originally posted by: Gibsons
imhotep - virii do have introns ("junk DNA." though that's perhaps a misnomer in any case) and splice them. I don't have any sort of number how much of a viral genome is typically non-coding though. I imagine it varies quite a bit.

althoguh virii may have introns they cannot splice them on the own as they do not have spliceosomes nor any other kind of protein for that matter(except for the protein the makes up their capsid,their out covering.) A virus is simply a strand of dna or rna or a double strand of dna or rna, (yes there is double stranded RNA) sorrounded by a protective proteincovering. They may have specialized proteins that can reconize protiens on the outside of theirtarget cells. Virii are not considered alive becuase htye do not have the ability to reproduce on there own. THey have no metabolic stuctures(they cannot make or convert energy to a usable form) with out energy they cannot make any proteins.

A virus inserts it genetic material into a cell which may code for the destruction of the cells dna and then code proteins for its capsid and reproduce its own gentic material. THe cell will burst and the virii are released to infect other cells. that is called the lytic cycle. Some viruses enter the lysogenic cycle when the dna from the virus combines with the dna of the cell and is reproduced with the cell. THe cell continues to live until something causes the viral genetic material to be transcipted and code proteins.

So if they dont have a spliceosome then that would mean that they use the hosts machinery. Interesting, does that mean viruses may have evolved from eukaryotic cells? Or could it be that the virus acquired it after infection of a eukaryotic cell from a random recombination event?

Imouthes

Yes thar is correct the virus will use the cells machinery. The recombination frequency of viral genteics is so high that is i very hard to trace where virii evovleved form.

 

[imhotepmp]

Originally posted by: bigal40

Originally posted by: imhotepmp

Originally posted by: bigal40

Originally posted by: Gibsons
imhotep - virii do have introns ("junk DNA." though that's perhaps a misnomer in any case) and splice them. I don't have any sort of number how much of a viral genome is typically non-coding though. I imagine it varies quite a bit.

althoguh virii may have introns they cannot splice them on the own as they do not have spliceosomes nor any other kind of protein for that matter(except for the protein the makes up their capsid,their out covering.) A virus is simply a strand of dna or rna or a double strand of dna or rna, (yes there is double stranded RNA) sorrounded by a protective proteincovering. They may have specialized proteins that can reconize protiens on the outside of theirtarget cells. Virii are not considered alive becuase htye do not have the ability to reproduce on there own. THey have no metabolic stuctures(they cannot make or convert energy to a usable form) with out energy they cannot make any proteins.

A virus inserts it genetic material into a cell which may code for the destruction of the cells dna and then code proteins for its capsid and reproduce its own gentic material. THe cell will burst and the virii are released to infect other cells. that is called the lytic cycle. Some viruses enter the lysogenic cycle when the dna from the virus combines with the dna of the cell and is reproduced with the cell. THe cell continues to live until something causes the viral genetic material to be transcipted and code proteins.

So if they dont have a spliceosome then that would mean that they use the hosts machinery. Interesting, does that mean viruses may have evolved from eukaryotic cells? Or could it be that the virus acquired it after infection of a eukaryotic cell from a random recombination event?

Imouthes

Yes thar is correct the virus will use the cells machinery. The recombination frequency of viral genteics is so high that is i very hard to trace where virii evovleved form.

In regards to the recombination comment I was referring to the virus having introns without the machinery. In other words, the virus probably obtained introns thru some wacko recombination event with a eukaryotic cell, since introns are strictly a eukaryotic feature.

Imouthes

 

[Gibsons]

Regarding introns -

There's some debate about whether introns (or really, RNA splicing in general) evolved late or early... I'm not entirely up to date on the argument, but the last I saw the "introns early" theory seemed to have more support. This would mean that eukaryotes (and therefore probably virii) have pretty much always had introns/exons. Maybe somewhat counter-intuitive (makes me scratch my head anyway), but then again it still seems to be an open question (search pubmed for "introns early").

 

[g8wayrebel]

[/quote]

Original post : gururu 7/16/2002

Prior to the major 1918 global pandemic, 'flu was a relatively minor illness. Yes, it was dangerous to the infirm, elderly and young, but death was unsual (estimated at probably less than 1 in 1000).

Something was different about the 1918 virus. It was much more contagious and much more virulent. It would rapidly infect young fit people, and they would develop pneumonia and die (death rate probably 1 in 40).

his was probably not so much due to a significant change in the virulence of the virus, but instead because it had 'changed its spots'. Flu viruses endemic in a population don't generally cause much illness because the population is immune. Slow changes in the virus mean that the population can retain some immunity against slightly different viruses. The big pandemics are thought to have occurred because the virus simply picked up a new coat from another virus (e.g. from swine flu or bird flu), to which the population have no immunity at all. original post: gururu 7/16/2002 [/quote]



I think you have failed to consider the human race in the equation. The outbreaks of the early 1900 's and especially in the 1600's could very well be due to demographics in and of themselves. We are a very mobile society who is well informed today. In those periods specifically there were groups of people brought together from totally different worlds so to speak. The adaptation of one group would be much different then that of another. That being the case, you would have people being exposed to, at the very least, strains of virus, if not completely different viruses than they had ever encountered before. If you recall it wasnt to long ago we were quarantining people before allowing them to move freely in this country. How bad would it have gotten without our communication systems and the fast transportation we now have allowing most of the world population to have at least a minimum resistance built to most of the viruses in question.:light:





The best antibiotic in the world is your own mucus,so, pick your nose, just don't get caught. :beer:

Actually, it probably isn't completely.

 

[gururu]

Originally posted by: g8wayrebel

Original post : gururu 7/16/2002

Prior to the major 1918 global pandemic, 'flu was a relatively minor illness. Yes, it was dangerous to the infirm, elderly and young, but death was unsual (estimated at probably less than 1 in 1000).

Something was different about the 1918 virus. It was much more contagious and much more virulent. It would rapidly infect young fit people, and they would develop pneumonia and die (death rate probably 1 in 40).

his was probably not so much due to a significant change in the virulence of the virus, but instead because it had 'changed its spots'. Flu viruses endemic in a population don't generally cause much illness because the population is immune. Slow changes in the virus mean that the population can retain some immunity against slightly different viruses. The big pandemics are thought to have occurred because the virus simply picked up a new coat from another virus (e.g. from swine flu or bird flu), to which the population have no immunity at all. original post: gururu 7/16/2002 [/quote]



I think you have failed to consider the human race in the equation. The outbreaks of the early 1900 's and especially in the 1600's could very well be due to demographics in and of themselves. We are a very mobile society who is well informed today. In those periods specifically there were groups of people brought together from totally different worlds so to speak. The adaptation of one group would be much different then that of another. That being the case, you would have people being exposed to, at the very least, strains of virus, if not completely different viruses than they had ever encountered before. If you recall it wasnt to long ago we were quarantining people before allowing them to move freely in this country. How bad would it have gotten without our communication systems and the fast transportation we now have allowing most of the world population to have at least a minimum resistance built to most of the viruses in question.:light:





The best antibiotic in the world is your own mucus,so, pick your nose, just don't get caught. :beer:

Actually, it probably isn't completely.

That's not my quote!!!!!

 

[g8wayrebel]

No. your'e correct and I apologize. I did give you credit,but the quote was an after thought so by necassity the credit was as well. The system doesn't cooperate too well with additions of that kind, and I must have gotten dyslexic when I went back to get the info......Ammendriginal qoute .Mark R. 10/9/1999. For the record, although it is a valid source of exposure,and therefore by necessity an assistance to immunity, I was just being facetious about picking your nose to lighten the subject a little.
It's nice to know people actually use these forums even though the quote was from ions ago

 

[PlasmaBomb]

Originally posted by: Mark R


In the last ten years, there's been an influx of new strains that are slightly more resistant to antivirals, but that has nothing to do with the conditions of transmission. It is simply that we are selecting for mutants with an increased tolerance to drugs.

Yes varii evolve, when one of the first commercial antivirals was used in the US (AZT), varii were found with resistance within 2 years of its introduction. Resistance was even found in patients who had never been treated with AZT.