Question

Question 25 of 25 > Attempt 2 - To answer this question, please reference the Problem Solving Video: Free Energy, ATP, and Creatine in Resting Muscles. The standard free energy (AG") of the creatine kinase reaction is - 12.6 kJ mol". The AG value of an in vitro creatine kinase reaction is -0.1 kJ mol". At the start of the reaction, the concentration of ATP is 5 mM, the concentration of creatine is 17 mm, and the concentration of creatine phosphate is 25 mM. Using the values given, calculate the starting concentration of ADP in micromolar. (ADP) =

Answer 1

creatine + ATP -----------> ADP + creatine phosphate     $\Delta$ G0   = -12.6KJ/mole

$\Delta$G   = -0.1KJ/mole

[Creatine phosphate]   = 25mM = 25*10^-3M

[Creatine]                   = 17mM    = 17*10^-3M

[ATP]   =5mM = 5*10^-3M

$\Delta$G     = $\Delta$ G0 + RTlnQc

-12600   = -100 + 8.314*298lnQc

-12600+100 = 8.314*298lnQc

-12500   = 2477.57lnQc

lnQc = -12500/2477.57

lnQc = -5.045

Qc   = 6.44*10^-3

Qc    = [Creatine phosphate][ADP]/[creatine][ATP]

6.44*10^-3   = 25*10^-3[ADP]/17*10^-3*5*10^-3

[ADP]   = 6.44*10^-3*17*10^-3*5*10^-3/(25*10^-3)

[ADP]   = 2.1896*10^-5 M

[ADP]   = 21.896*10^-6M

[ADP]   = 21.896$\mu$M >>>>>answer