How many atoms in a human cell?

aznHypnotix

"A person's body is actually made up of trillions of cells (source: Science Concepts - Cells by Silverstein)", but how many atoms could fit inside a human cell?

125 million atoms could fit inside the period at the end of this sentence. But how many atoms could fit inside a single (prokaryote, eukaryote, animal, human, or plant) cell?

Gokul43201

A typical human cheek cell has a volume of about 10^-13m³. With some assumptions and approximations, I have 10¹⁶ atoms, give or take a couple of orders of magnitude.

DaveC426913

"125 million atoms could fit inside the period at the end of this sentence."

This seems conservative in the extreme.

Pengwuino

Maybe he meant with room to spare

Gokul43201

If you consider the period to be two dimensional, I'd imagine that estimate being conservative by only a couple or so orders of magnitude.

Hereforwisdom

125 million atoms in the period at the end of this sentence would seem accurate though all you would see off the computer screen would be light. So actually there would be no mass therefore no atoms(excluding the flowing electrons in the computer screen). Otherwise a palpable ink dot would most likely contain 125,000,000 atoms

DaveC426913

How do you back this up?

alxm

And most of the cells in the human body aren't human. Which is pretty indicative of the vast difference in size between human cells and bacterial ones. And there's a big difference between different human cells.

E-Coli has 5.44 million base pairs in its DNA. Reckoning ~30 atoms per nucleotide, 125 million atoms wouldn't even cover half the atoms in its DNA.

Andy Resnick

estimating the volume of a cell as 10 cubic microns, and a density 1.3 times that of water, gives 4.5*10^11 atoms/cell.

A dot of ink, 1 micron thick and 0.5 mm in diameter has a volume of 7*10^5 cubic microns.

Zzeusest

Quote by aznHypnotix "A person's body is actually made up of trillions of cells (source: Science Concepts - Cells by Silverstein)", but how many atoms could fit inside a human cell? 125 million atoms could fit inside the period at the end of this sentence. But how many atoms could fit inside a single (prokaryote, eukaryote, animal, human, or plant) cell?

On November 2, 2009, according to the National Geographic, "Each cell in the human body contains about 100 times as many atoms as there are stars in the Milky Way. As we all know, the Milky Way has ~ 200 Billion stars. SOOooo, 200,000,000,000 X 100 = 2.0 × 10¹³. Long story short, it's about, 200 trillion. Now, that's magnificent isn't it!

Hold your horses my little stem cells, Science NetLinks, a resource for science teachers, stated that there are approximately "ten to the 14th power" (that's 100 trillion) cells in the human body. SOOOooo, 200 trillion atoms in 1 human cell X 100 trillion cells in the average human body = a whopping, 200 septillion. That's a 2 with 24 zeros following it! Are you conceptualizing this! We have 100 times more atoms in out body than stars in the universe! ^{[Please see footnote "A"}

Let's not stop there shall we? How about 200 septillion atoms in the average human body X, as of November 2, 2009, the Earth's population is estimated by the United States Census Bureau to be, 6.794 billion = 13.588 X 10 ³⁴ ! GULP! I better go make breakfast. ()

Zeusest
The One and Only!
Even if I have 2 Z's in my registration name. Oops...

^{Footnote A} The total number of stars in the universe is roughly 100 billion x 100 billion.

That's 10,000,000,000,000,000,000,000 stars, 10 thousand, billion, billion. Properly known as 10 sextillion. And that's a very conservative estimate.

Zzeusest

Check out this for equal/opposite justification:

Go to youtbe and check this out. Absolutly astonishing!

http://www.youtube.com/watch?v=EDNEV9EW06g&NR=1

Then go to this, My Gosh!

http://www.youtube.com/watch?v=Zr7wNQw12l8&NR=1

qraal

Are there any authoritative sources for how much individual somatic cells mass?

I've read that there's about ~10 trillion nucleated somatic & white-blood cells in an average adult, about 25 trillion denucleated red blood cells and about 40 trillion bacteria of all stripes.

As humans - and most animals AFAIK - float, then the average density must be less than water. Most of the molecules in our bodies numbers-, if not mass-, wise are probably good old H₂O, then there's the CHON that makes up most of the carbs, lipids and proteins in our bodies... so, elementally, we're probably mostly oxygen. If an average human masses ~75 kg & they're roughly 8/9ths oxygen, then we contain roughly 4200 moles of oxygen. About 2.52E+27 atoms of oxygen - and the 35 trillion human cells contain about 72 trillion oxygen atoms each.

qraal

According to this source... Ed Uthman, MD site ...there's 43 kg of oxygen in a 70 kg human. So I should have said ~3/5 oxygen instead of ~8/9. Oh well. You can do all the figuring you like off the neat breakdown presented on the page. I suspected there was more oxygen because we're 70% water to start with and then oxygen is present in sugars/carbohydrates, bone, and other odds and ends. Oh well.

qraal

After throwing the data into a spread-sheet it's interesting to see how much hydrogen dominates in terms of numbers of atoms...

hydrogen 62.2%
oxygen 24.1%
carbon 12%
nitrogen 1.2%
phosphorus 0.2%
calcium 0.2%

...we're still mostly "star-stuff" especially if you count white-dwarf star-stuff ;-)

DaveC426913

True, though not in volume or mass.

qraal

Pretty pics Dave! Where'd you find that periodic table template?

DaveC426913

Thanks. I don't recall where I got the original PTotE. I just Googled until I found one that suited my purpose.