[krytie75 (OP)]

We've all heard Chris talking about how there are many more cells of foreign material (bacteria etc) in the human body than there are your own cells.  Now the way I see it, either that's a gross fabrication or the foreign cells are much smaller than our own.  Yes I know that living bodies take host to a vast number of microorganisms and they live very happily all over and in us, but I just can't believe that over half my body mass is comprised of foreign material.

For this to be so, the forgein material would have to be intrisicaly part of us (attached) or we would be very different indeed.

So what's the word?

[Don_1]

So that's why I'm the size I am. I must have a Beluga Whale inside me. Oi!!! Clear off mush, so I can fit into those jeans I bought 20 years ago.

[Variola]

No it is not a gross fabrication, it is true.

Estimates of how many cells make up the human body range from 50-100 trillion.( I would think it is nearer 100 trillion) However a typical eukaryotic cell measures approx 10 µm, where are bacterial ( prokaryotic) cells like E.Coli meausre 2µm, and some bacteria as small as 0.5µm in diameter or width and 1µm length for rod-shaped ones. 

As well as the bacteria inside the body, you have to remember the flora on the outside of the body, on the skin too which mooch about doing their own thing.

This is quite an accessible link

http://en.wikipedia.org/wiki/Human_flora

[Geezer]

Holy Moly!

I wish I knew what on earth you were talking about so I could argue with you. On the other hand, why should I let that stop me?

Obviously, Variola is completely deranged!

[Variola]

I'm waffling on about small squiggly things, a favourite topic of mine.  []

Obviously, Variola is completely deranged!

That is a moto statement if ever I heard one Geezer...  []

[John Chapman]

No it is not a gross fabrication, it is true.

While it may be true that Variola is completely deranged she is absolutely correct.

Bill Bryson, in his excellent book ‘A Short History of Nearly Everything’ described the human body as not so much containing bacterial cells as being more like a bacterial colony containing some by human cells. Estimates range from there being between 10 and 100 times as many bacterial cells as human ones.

And that’s not counting all the mitochondria. These are cell organelles (the miniature ‘organs’ within cells) that probably started life as independent bacteria and now live symbiotically within virtually all our cells. Some human cells (liver cells, for instance) can have several thousand mitochondria living (and reproducing) inside them. That nicely illustrates the difference in size between a typical human cell and a bacteria.
 

[Geezer]

Yikes! How long will I have to stay in the shower to fix this? I thought it was only my feet that had the problem.

(BTW, in case you missed it, check thread "Are you having a nice day?" re. FMIW)

[krytie75 (OP)]

Ok so to get a definitive answer to what I guess I was really asking, by mass, what makes up a bigger proportion of our bodies? Human cells or foreign cells?

[krytie75 (OP)]

So I may have just found the answer to this on that Wiki article.

"The average human body, consisting of about 10¹³ (10,000,000,000,000 or about ten trillion) cells, has about ten times that number of microorganisms in the gut."

This I guess shows that the foreign cells are much smaller than our own and human cells still make up the majority of the mass of a human body.  I would still be interested to know the exact ratio of mass though.  Anyone got any ideas?

[Geezer]

Fascinating and yet terrifying!

How do you differentiate between host and hangers on? DNA, or is it more complicated than that?

[Nizzle]

An exact ratio of mass is hard to give, since no two people would have the same ratio of mass between human and other cells.

And next to the Human flora, also remember that we have at all times some viruses/bacteria in our bodies fought and defeated by our immune system.

It's a fascinating world indeed..
Where chemistry makes things come alive

[Geezer]

Nizzle,

This has absolutely nothing to do with this thread, so the rest of you will kindly bugger off and ignore it.

When I was about eight years old, my parents took us (me, and my delinquent brothers) to Ostend for a vacation (this was a very, very long time ago). I remember going on a bus tour one day, and the tour guide was very pleased to point out several major chemical facilities that had been recently established. (BTW, my father was a pharmacist) Anyway, as our bus passed these facilities, the tour guide proudly pointed them out and referred to them as "poison works".

Obviously, this was a minor translation problem, but it was an eternal source of mirth to my Mum and Dad.

[Variola]

Ok so to get a definitive answer to what I guess I was really asking, by mass, what makes up a bigger proportion of our bodies? Human cells or foreign cells?

It terms of weight, 1.5kg of your body is made up of bacerial cells.

It's a fascinating world indeed..
Where chemistry makes things come alive

Urgh! You just had to mention the "C" word didn't you?!!  [xx(]

[Nizzle]

@ Geezer: Yes well, Ostend is a city in the province of Western Flanders, or in Belgium better known as 'the farmers province' []. That might explain a lot.

@ Variola: Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry Chemistry !!!
You can't fully understand life at these microscopic levels without it dear.

[RD]

So we have more "foreign" cells than human, bacteria-like mitochondria in every cell and our DNA sequence is mostly virus ...
 

“Viral elements are a large part of the genetic material of almost all organisms,” said Dr. Sharp, who won a Nobel Prize for elucidating details of our genetic code. Base for nucleic base, he said, “we humans are well over 50 percent viral.”.

http://www.nytimes.com/2008/01/08/science/08angi.html?_r=1&em&ex=1199941200&en=3bd96f63379d275d&ei=5087%0A&oref=slogin

[Pwee]

An exact ratio of mass is hard to give, since no two people would have the same ratio of mass between human and other cells.

And next to the Human flora, also remember that we have at all times some viruses/bacteria in our bodies fought and defeated by our immune system.

It's a fascinating world indeed..
Where chemistry makes things come alive

and than this:

It terms of weight, 1.5kg of your body is made up of bacerial cells.

No "maybe" no "around" no "approximately".
Just brilliant.

[John Chapman]

I think it's misleading to think in terms of 'human' and 'foreign' cells. All these prokaryotic (primitive) cells of bacterial origin are now an integral part of our bodies. They are vital to our existence, as we are to theirs.

How do you differentiate between host and hangers on?

It's almost like thinking about removing the donkey elements from a mule to get back to to original horse. We are now chimeras (I don't know the plura of chimera) of mixed origin. Hitler would have had a epi if the extent of this was known in the 1940's!

 

[Nizzle]

You could define Human cells as cells with a genome that differs less than 0.005% from a cell with a genome from, let's say 100 other humans.

Quote
“Viral elements are a large part of the genetic material of almost all organisms,” said Dr. Sharp, who won a Nobel Prize for elucidating details of our genetic code. Base for nucleic base, he said, “we humans are well over 50 percent viral.”.
http://www.nytimes.com/2008/01/08/science/08angi.html?_r=1&em&ex=1199941200&en=3bd96f63379d275d&ei=5087%0A&oref=slogin

This is true in both ways though: You could just as well say: "Viruses are well over 50% animal (or plant depending on the virus)". It all depends on how you look at it.
Hell, if you look at DNA as "a chain of A, C, G and T bases" our genome is 100% the same as viruses. Only the order in which these bases are present and the total size of the chain differs.
If you look at sequences of 4 bases, we might still see that 97% of these sequences in a virus also appear in human DNA
90% of all 8-base sequences of the virus appear in human genomes
And the longer you make the sequence, the less % we'll see returning in human genomes.
If you consider a virus with a genome of 40.000 bases, you will not find the exact same sequence of 40.000 bases in a human genome and we have 0% resemblance.

It's just a fact that DNA as a system of transferring information evolved once, and all living creatures share this method (or RNA as an alternative, which is DNA + a bit more oxygen) of transferring information.

[RD]

Ok so to get a definitive answer to what I guess I was really asking, by mass, what makes up a bigger proportion of our bodies? Human cells or foreign cells?

It terms of weight, 1.5kg of your body is made up of bacerial cells.

Most of them end up in the crapper ...

The colon contains large numbers of bacteria that make up about one-third to one-half of the dry weight of the faeces..

http://tripatlas.com/Human_feces

faecal bacterial mass accounted for 44 and 35% of faecal dry weight

http://www.nature.com/ejcn/journal/v61/n2/full/1602496a.html

[Variola]

No "maybe" no "around" no "approximately".
Just brilliant.

That was paraphrasing from Molecular Cell Biology 2007 by Harvey Lodish et al.It is hardly my own guess.

Given the quantification that had gone before, I didn't deem it necessary to put approximate next to it.

However Pwee if you wish to get snotty with me on here do go ahead, I am always looking for my next meal.