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Author Topic: Where do the extra atoms come from when a life form grows?  (Read 1474 times)

Offline Thebox

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A rock is a rock and grows by gaining more atoms in the form of dust,



we grow from conception so where does the dust come from?



 

Offline chiralSPO

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This depends on the life form that is growing.

Almost all of the atoms in our bodies come from the food and water that we ingest (and a small fraction from the air that we breath).

Plants get a large percentage of their mass from the air, but also absorb water and minerals through their roots.
 

Offline evan_au

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Placental mammals (like humans) get their extra atoms and molecules across the placenta, from food and water ingested by the mother.
 

Offline Thebox

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I thought the Human body extracted energy from food and water, and there remains a waste product, which I presume is also is made of atoms, so you are saying that we grow because we steal atoms out  of food and water, leave some atoms, (rather picky), and then expand my gaining more mass as opposed to growing our own biological mass?

 

Offline Colin2B

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....... so you are saying that we grow because we steal atoms out  of food and water, leave some atoms, (rather picky), and then expand my gaining more mass as opposed to growing our own biological mass?
You got it, all chemical reactions.
Did you think we make our own atoms from electrons, protons and neutrons or quarks etc?
 

Offline Thebox

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....... so you are saying that we grow because we steal atoms out  of food and water, leave some atoms, (rather picky), and then expand my gaining more mass as opposed to growing our own biological mass?
You got it, all chemical reactions.
Did you think we make our own atoms from electrons, protons and neutrons or quarks etc?

Well, I sort of think we are not like stuff that things are made of like a table. I never observe my table growing, even from birth when it first became a table.


I just think that maybe cellular growth is different some how and atoms sort of grow/clone



 

Offline Colin2B

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Well, I sort of think we are not like stuff that things are made of like a table. I never observe my table growing, even from birth when it first became a table.
That's right, the table is not a living organism, but the tree it was made from was living and processed various atoms and molecules to make wood.
I just think that maybe cellular growth is different some how and atoms sort of grow/clone
No, it's conversion from one form to another, we don't manufacture atoms.

Of course you don't have to believe me  ;)
 

Offline Thebox

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Well, I sort of think we are not like stuff that things are made of like a table. I never observe my table growing, even from birth when it first became a table.
That's right, the table is not a living organism, but the tree it was made from was living and processed various atoms and molecules to make wood.
I just think that maybe cellular growth is different some how and atoms sort of grow/clone
No, it's conversion from one form to another, we don't manufacture atoms.

Of course you don't have to believe me  ;)

I have no theories on life, I can not even comprehend it, I will stick to rocks and believe we are made of the same thing.
 

Offline Alohascope

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What processes create the heavier elements in our bodies like copper?  Can our bodies actually restructure atoms?
 

Offline evan_au

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Quote from: TheBox
I just think that maybe cellular growth is different some how
The unique thing about life is that it is able to take matter that is around it, and conscript it to form more of itself.

This formation of more order out of less order is an indication that life produces a (local and temporary) reduction in entropy. This process takes energy, which we obtain from our food and (ultimately) sunlight, via photosynthesis. It also takes raw materials (atoms and molecules), which we obtain from food, water and air.

It does this at the cost of an increase in entropy, when viewed at a larger scale, over longer timescales.

Life flourishes best in an ecosystem of many different organisms.

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I will stick to rocks and believe we are made of the same thing
We are made of the same atoms as rocks, but in different ratios and in different molecular arrangements (although peat comes fairly close, being once-living material).

Even a rock can grow an orderly crystal, if put in the right conditions. But this is not classified as "life".

 

Offline evan_au

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Re: Where do the extra atoms come from when a life form grows?
« Reply #10 on: 08/02/2016 20:20:06 »
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What processes create the heavier elements in our bodies like copper? 
Most of the elements up to iron and copper are formed in the heart of large stars. These are spread into space by supernova explosions. Elements heavier than this are formed in the fury of the supernova.
The resulting dust cloud formed into the Earth, these elements were taken up by plants, eaten by humans, and then used in the human body.

As Carl Sagan loved to say "We are all star-stuff".
See: http://en.wikipedia.org/wiki/Stellar_nucleosynthesis

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Can our bodies actually restructure atoms?
We can restructure the outer electrons of an atom during digestion, eg copper metal can be turned into a copper ion by the acid in our stomach.

We use enzymes to break apart molecules and groups of atoms, and restructure them into the molecules that our bodies need.

Hydrogen has only one electron, and when this electron is removed, you are left with just the nucleus (a proton) dissolved in water. Our bodies use this effect all the time (eg in our stomachs), but it also happens all the time, just in a glass of water.

There are some radioactive elements like potassium-40 where the nuclear structure of the atom slowly changes over time due to radioactive decay; potassium-40 turns into Calcium or Argon. We know of no cases where living things today can affect the rate that these nuclear reactions occur. 
 

Offline Ophiolite

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Re: Where do the extra atoms come from when a life form grows?
« Reply #11 on: 08/02/2016 20:43:13 »
A rock is a rock and grows by gaining more atoms in the form of dust,
Well no, not really true unless you have a very wide definition of dust.
An igneous rock grows through crystalisation of minerals from a cooling magma. A metamorphic rock does not grow at all, but merely changes. (Strictly speaking some changes of composition may occur as fluids or ions migrate through the rock.)
Sediments grow by deposition of more mineral or shell fragments, or crystalisation of minerals from solution, and are then converted to sedimentary rocks through compaction and cementation. 
 

Offline alancalverd

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Re: Where do the extra atoms come from when a life form grows?
« Reply #12 on: 08/02/2016 22:29:17 »
A rock is a rock and grows by gaining more atoms in the form of dust,

Quite the opposite of Democritus' observation that rocks erode into dust, which started the whole business of atomic theory.
 

Offline jeffreyH

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Re: Where do the extra atoms come from when a life form grows?
« Reply #13 on: 09/02/2016 00:27:39 »
That just shows why observation is so important. This is how science has always progressed and can sometimes lead to intuition as to how a system might be expected to behave theoretically. Why can't people get it into their heads that scientists haven't just been wildly speculating over the centuries?
 

The Naked Scientists Forum

Re: Where do the extra atoms come from when a life form grows?
« Reply #13 on: 09/02/2016 00:27:39 »

 

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