350 7 Chemical Equilibrium7.70 All or nearly all of the processes in a living organism seem
to be driven by coupling with the hydrolysis of ATP. The
body of a 70-kg person contains about 50 g of ATP.^9
(^9) R. H. Garrett and C. M Grisham,Biochemistry, 3rd ed., Thomson-
Brooks/Cole, Belmont, CA, 2004, p. 73.
The molar mass of ATP is 0.551 kg mol−^1. Find the amount
of 50.0 g of ATP in moles. Assume that the person ingests
food equivalent to 2500 kcal per day and that 40% of this
energy is available to regenerate ATP and that the
regeneration requires 35 kJ mol−^1. Estimate the number of
times that ATP is regenerated in one day.