How do atoms build us

the culture of deference

I understand that 96% of my body is made up from 4 elements.

When I was created where did the atoms needed to build my body originate from on Earth, and how did they get the correct amount at the right time.

(I have a science background.)

Capt'n Midnight

Your body sorts out the elements it needs from the enviroment. And usually gets it right but sometimes another element of similar size and properties can be incorporated. Fluoride in teeth helps prevent decay. Radioactive Strontium in bones istead of calcium is not good. Some worms in the UK are now able to incorporate Arsenic in place of phosphorus in somethings, and IIRC some baceria can use it even more.

Example the earths crust contains 8% Aluminium but we don't use it much. So it's not about what is plenty full, but rather what works. Phosphorus is comparitively rare and we rely on it for DNA (long term information store - the code hasn't change much in the last 3 Billion years) and ATP (temporary energy store ~ seconds / intermediary)

Or compare the usages of Potassium and Sodium relative to their abundances.

Ratios of Oxygen and Iron in the universe are down to a cheat in stars, I'm really surprised how little creationists mention it.

After the proto-earth was hit by a mars sized object all the volatiles would have presumably been boiled off, and anothery theory is that the heavier elements in the crust came from asteriods after the cust solidified because before that they would have sunk into the core.

the culture of deference

Capt'n Midnight wrote: »

Your body sorts out the elements it needs from the enviroment..

How?

Capt'n Midnight

the culture of deference wrote: »

How?

Biology


To oversimplify cells are a bag of soup. The bag is made of fat (lipid) and protein. The fat separates the soup from water and solids in the envirionment. So apart from gases which can diffuse across the membrane it's usually up to proteins to control what gets transfered into/out of the cell. ( Ameobas and white blood cells can engulf stuff but that's a different story. )

Transfer of atoms can be passive like osmosis, or active where there is a kind of pump but it gets very complicated


Or if you look the other way DNA is very specific and it translates to molecules with a specific shape and electrical poperties that can influence the way atoms bond together.

the culture of deference

the culture of deference wrote: »

How?

I saw Capt'n Midnight's reply so I didn't bother replying, but I think maybe it's a more basic level you're thinking of. You get your atoms from the food you eat.

Your mother's egg contained all the cellular components necessary (mitochondria, membrane, DNA etc.). Your father's sperm fertilised the egg, giving the cell a full DNA genome. While in the womb the cell was provided with nutrients (amino acids, lipids, energy etc) and it divided loads of times. So basically the food that your mother ate, was metabolised by her to the stage of basic building blocks of a cell, and given to you via (AFAIK) the placenta. Then after you were born you assimilated your own nutrients, which were supplied to your cells through metabolic processes, and then your cells underwent division.

You say you have a science background so I know you probably already know this, but I think what you're missing is the pathway that food goes along. It all comes from one original cell, supplied with food that's been broken down by your body.

the culture of deference

Thanks for the replies guys, but as you said I know all this, I want to know how the right combination of atoms are there.

I have read countless books but never one that specifically explains this.

nozzferrahhtoo

I think the main problem you will face with finding an answer you your question is that you are asking a relatively simple question that encompasses a massive amount of complexity from one end to the other… and it is entirely unclear from your questioning this far exactly what part of that long end to end process you are actually asking about with your questions.

Atoms do not, essentially, build “us”. Atoms react with each other. That is all atoms do. (Simplification but good enough for this point in the conversation.)

In doing so they build molecules. They do very little but react with each other too. (Simplification but good enough for this point in the conversation.)

In doing so they build nucleotides and amino acids . Again they pretty much just react with each other too ((Simplification but …. You get the picture) and you get RNA and DNA.

Then you get poly peptides and proteins and so on, and they all react with each other too, and with amino acids and nucleotides.

So there is no simply end to end answer on how atoms build “us”. Instead you have to look at what atoms do build, understand that. Then the things atoms build… look at what they IN TURN build and understand that. Then…. so on so on. Alternatively of course you can start from the “top” and work down to atoms, but essentially in the same way.

Each step in that conversation will lead you to massive science books, so really there is no simple answer you will learn from a forum post from anyone, much less me, that will answer what you are asking. Nor are you likely to find one book that will "specifically explain this" as you put it. However there is a chapter on embryology in Richard Dawkins "The Greatest Show on earth" which will go a large way to explaining current scientific thought on how one single cell "knows" how to split and split and split and what makes it turn into bone in one place, skin in another, organs in another and how it "knows" where it all goes and fits together.

the culture of deference

the culture of deference wrote: »

I want to know how the right combination of atoms are there.

Ok, I'm going to have another try, nozzferrahhtoo hit the nail on the head though, even though you're asking your question in clear language, what exactly it is that you're looking for is still unclear.

So, the right combination.

The atoms aren't just separate, they're part of compounds, so it's probably more sensible to talk about this in terms slightly bigger than atoms. There is a particular number of cells in our body, regulated by mitosis and apoptosis. If we aren't eating enough of a certain type of compound, eg. salt, we get hungry for salt. If we don't eat it, we get sick. If we eat too much of it, we get sick, so the only thing regulating it (with the exception of osmotic pressure issues going on in your kidneys) is us, making the choice of whether to eat it or not. Stuff like fat and carbohydrates, if we eat too much of it we store it (hence why some of us have quite a few more atoms than others). If we don't eat enough fat/carbs we get sick. So basically, if the amount of atoms that we need aren't there, we get hungry, growth and repair suffers, and if we eat more atoms than we need, we get fat/sick/pass some of it as faeces. So basically we ourselves, with the help of certain homeostasis mechanisms, regulate the amount of atoms we get, and the combination in which we get them.

Capt'n Midnight

The most common molecule in your body is Water = H2 O (2 Hydrogen atoms for every Oxygen)

The least common molecule is DNA - one of each per cell.
DNA is composed of 4 Different Nucleic Acids (the -NA part, the rungs on the ladder)

Adenine: C5H5N5

Guanine: C5H5N5O

Cytosine: C4H5N3O

Thymine: C5H5N2O2

The sides of the ladder are made from these

Phosphate: PO4

2-deoxyribose: C5H9O4 (This is the D-- part)

So if we sequenced your DNA we would know exactly how many atoms of each type there were in the DNA of your cells.


DNA is a list of protein sequences.

Parts of DNA (the master set of drawings) are copied to one or many copies of RNA (the working drawings) depending on how much of each protein is needed.

Proteins make up skin, hair ,nails, connective tissue , enzymes, haemoglobin. Without protein your bones would be like chalk. If you have even seen how weak fibre glass after it's been burnt.


<skip lots>

If you become dehydrated you will feel thristy and will drink. It's one of the ways your body regulates the amount of H2O in it.

the culture of deference

Thanks for the replies guys but I still know everything you have said so far.

I have read many " massive science books" and my question is still in regards to how the right amount of atoms exist locally to build me and every single one of us.

IrishKnight

the culture of deference wrote: »

...question is still in regards to how the right amount of atoms exist locally to build me and every single one of us.

I'm not sure if I am interpreting you question right but sure I'll give it a shot.

Ultimately the right amount of atoms (or rightly said molecules) don't exist locally at any given point, rather we acquire them throughout our development. While in the womb our mother provides said molecules, when we are growing up we get them via our diet.

While writing this another interpretation crossed my mind which I will try to phrase. Are you asking where we are getting the building blocks for the total population of earth? i.e. considering that our population is increasing and what not, where are all the raw building blocks coming from. Is that what you are asking?

the culture of deference

IrishKnight wrote: »

I'm not sure if I am interpreting you question right but sure I'll give it a shot.

Ultimately the right amount of atoms (or rightly said molecules) don't exist locally at any given point, rather we acquire them throughout our development. While in the womb our mother provides said molecules, when we are growing up we get them via our diet.

While writing this another interpretation crossed my mind which I will try to phrase. Are you asking where we are getting the building blocks for the total population of earth? i.e. considering that our population is increasing and what not, where are all the raw building blocks coming from. Is that what you are asking?

Sort of....

I understand that if you took the total amount of atoms in 7 billion humans (and compressed the empty space out of it), it would be the size of a thumbnail or less.

We know that atoms can only be created in stars, therefore there is a finite number of them. I am re reading all of my Dawkins books again, the GSOE seems to be written for mass market compared to the selfish gene. I am currently halfway through Ancestors.

I am finding it hard to explain to my kids and I was hoping the question could be answered in a simplistic way while turning off my inbuilt scientist.

The kids (11 and 9) lose patience when dad goes into a huge long complicated explanation.

ClimberC

Might as well have a go.......

My understanding is that energy cannot be created or destroyed, only changed from one form to another....... and since E=mc2 any mass and or energy was present at the "Big Bang". So all the matter or atoms we are made from is as old as the universe.

Atoms are not created in stars as such, they just fuse (hence Fusion). these are dispersed through solar mass ejections. these are then Picked up by animals eating grass and in turn by us from eating animals. Any atoms your body requires will be used..........

This is by no far my area of science so sorry if its not correct but that's my understanding of it :cool:

rccaulfield

The atoms themselves come from high mass star reactions and are released through that stars deathand resulting explosion into a nebula-then onward toward the next generation stars birth, then planetary evolution etc etc. As for the right quantities well wherever life evolves it will use whats there to survive. 4.5 billion years is a long time!

Capt'n Midnight

rccaulfield wrote: »

As for the right quantities well wherever life evolves it will use whats there to survive.

Actually life is very specific about which elements it uses. Silicon and Aluminium are very common. Silicon is generally only used by plants in it's inorganic form and even at that it's usually used make the pant physically harder to eat. (and nettle stings)

Compare the ratios of elements in the environment and living organisms to see just how selective life is.

steddyeddy

Well everything is made of atoms. The study of biochemistry and molecular biology looks at the chemical compisitions of the body. Many processes in the body are a result of chemical reactions. The one that I find interesting is the manner in which the body creates energy or ATP.

rccaulfield

Capt'n Midnight wrote: »

Actually life is very specific about which elements it uses.

On which planet:p we have a base study of 1. My point is its a back to front question.

kiffer

there is also a huge amount of geology/minerology stuff explaning why we don't just have a big evenly mixed up pile of all the elements...

I tried to write a short post on it but it's too much to write on my phone...

Stars, supernova, radioactive decay make give us the elements... Other than the starting H, He (and Li?)...
If we mix all the elements up in a big cloud of dust and let it settle into a planet, why do we end up with some bits that are rich in iron, and some bits that are rich in gold and so on? Or more biologically important things...

You'll have to look up Bowen's reaction series, fractional cystalisation, partial melting, the rock cycle, weathering rates for different minerals and so on... Heck a whole lot more.

Much of this means that it doesn't really matter all that much exactly what mix you start with, you'll end up with the same minerals (the rock cycle will produce feldspars, feldspars will weather to clays) on different planets concentrating elements in the same way, so life will have have similar selections of elements although exact amounts may differ.
The soils will still be made of clay from feldspars, sands will still be made of silica from quartz.
((gross over simplification, it's the middle of the night, life in the clouds of jupiter aside, I'm only thinking of rocky vaguely Earth/Mars like worlds here))

In a lot of ways the shorter the question the bigger the answer.

Most of your mass is made of of Carbon, Nitrogen, Oxygen and Hydrogen... You get this from your food, which ultimately means plants... Plants get most of their mass by using sunlight to turn air and water into sugars... Plants are mostly made from stuff they take from the air, you are mostly made from stuff you take from plants (and animals which take it from plants)...
You are made of air and sunshine...