|MadSci Network: Cell Biology|
Hi John, Your question about how much ATP we make each day is an interesting one! Here's what I've found out. An adult woman needs to burn about 1600 kcal of fuel each day, and our body's fuel is ATP. Each mole of ATP releases about 8 kcal of energy and we can assume that we MAKE just enough ATP to get by in a day. (Let me quickly try to describe what a mole is. A mole of molecules is the number of molecules it takes to convert from atomic mass units to grams. For instance, the weight of one molecule of water is 18 amu, but if you have 6.02 x 10^23 molecules of water, it would weigh 18 grams. So 6.02 x 10^23 molecules of anything converts the weight from amus to grams. If this doesn't make sense, you'll learn about it in chemistry). So, doing the math we get: 1600 kcal/day/8 kcal/mol= 200 mol ATP/day. Then we can convert from moles of ATP per day to molecules of ATP/second. 200 mol/day/86400 sec/day= 2.3 x 10^-3 mol ATP /sec Then converting from moles to molecules: 2.3 x 10^-3 mol/sec x 6.02 x 10^23 molecules/mol= 1.4 x 10^21 molecules/sec. This is a lot bigger than the number that you gave me. But I think the math is correct. The references I used are: Biochemistry by Voet and Voet copyright 1990. p. 554. There is also an article in Scientific American about this. Scienctific American 238(3) p.104-123 (1978) Admin note: With approximately 10^14 cells in the human body, the rate would come to about 10^7 (10 million) ATP molecules/sec per cell.
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