# At any given moment, how much energy is stored in the human body as ATP?

At any given moment, approximately how much energy is stored in the human body as ATP in the ADP-P-bond?

This of course depends on what type of cell it is and the activity of the individual in question. The calculation should be fairly simple, as we know that ATP hydrolysis release about 30 kJ/mol. Hence, the question could actually be re-phrased to $"$At any given moment, how much ATP does the human body have?$"$

• how much googling have you done? I'd start with "how many ATP molecules in human body" and then multiply that estimate by 30kJ/mol – aaaaa says reinstate Monica Jan 19 '16 at 15:48
• All I can find is how much ATP the human body uses per time unit. I'm not seeking that but rather how much present ATP there is at a given time. – Markus Klyver Jan 19 '16 at 15:52
• that is generally expected that you'll add what you;ve found to your question. Is makes it much better – aaaaa says reinstate Monica Jan 19 '16 at 16:01
• what do you think of following approximation: ATP is not a long-term storage hence every day you consume all ATP you produced from food/fat. That means that on average day-to-day you have X mol ATP/min * 24 hr? where X is the number of ATP/min body burns. – aaaaa says reinstate Monica Jan 19 '16 at 16:04
• I'm not looking for that either. If you froze time and started to count all ATP molecules in a human body, that's the number. – Markus Klyver Jan 19 '16 at 17:05

ATP burned per minute is not a useful number because the turnover is so high. 2000 kcal/day is dozens of kilograms of ATP so obviously ATP is turned over more than once a day, but there's probably more than one molecule of ATP being passed around between all the ATP synthases.

This blog claims 250 grams. Taking the estimate of ATP concentrations(1-10 mM) from wikipedia and multiplying by a 60 kg person pops out 150 grams (for 5 mM). The ATP/ADP ratio is about 5 to 1 under physiological conditions, so I'm comfortable leaving out that source of error.

So: Probably a few hundred grams, depending on a lot of things. Which is about .2-.7 moles, for reference. 6-20 kJ is not a lot, in fact even at the upper end of estimates you're looking at maybe 8 dietary calories, and probably more like 3.

Each of us burns approximately twice our body weight in ATP every day. So double your body weight and divide that number by the number of seconds in one day; that will give you the average mass of ATP. N.B. a person with a higher mass will have a higher answer.

• Is there a reference for that? – AMR Jan 20 '16 at 5:29
• My memory may not be what it used to be, but I thought I read a quotation by Paul D. Boyer (Nobel Prize recipient in 1997 for his work on ATP synthesis) where he cited that figure, but I may be off by a factor of 2 according to this slightly more well-known source which says "equivalent to your body weight": en.m.wikipedia.org/wiki/Adenosine_triphosphate – mdperry Jan 21 '16 at 1:33