Basically - the title: How much Oxygen does a human body carry at a single point?
What have I tried: A friend of mine has done some calculations and came up with the following numbers. Neither of us are biologists or have higher degrees in biology. His calculation went something like:
- Our body absorbs about 0.033g of Oxygen when we inhale (source).
- That's about 0.00103 moles of oxygen.
- Through ATP reaction that's about 0.00515 moles of ATP
- We have 270 millions of hemoglobin per red blood cell, and roughly 25 trillions of blood cells in our body (wiki), and each Hemoglobin molecule "carries" up to 4 oxygen molecules.
- Thus, in total, our body's hemoglobin can carry about (2.5 * 10^13) * (270 * 10^6) * 4 = 1.437 grams of oxygen
How far is the 1.437g number have?
Related (but not the same question) question I found here: How much energy we get from oxygen?.
Note: this is specifically about oxygen we use in our respiratory system - and not the oxygen in the water :]