Question

Myoglobin concentration is about 0.2 mM in beef muscle cells. At the ox ygen level equilibrated with blood Hb (0.1 mM), the Mb is 90 % saturated. That is, Mb-O2 = 0.18 mM andMb-deoxy= 0.02 mM. From this assumed equilibrium, including O2 , calculate the apparent delta G naught ’ of the binding reaction.

Answer 1

Solution :-

Mb      +    O2 --- >    Mb-O2

0.02 mM   0.1 mM     0.18 mM

Using the equilibrium values we can find the reaction quotient Q

Q= [Mb-O2]/[Mb][O2]

Q =[0.18]/[0.02][0.1]

Q= 90

Using the value of Q we can find the delta go value

Delta Go = - RT ln Q

                = -8.314 J per mol K * 298 K * ln [90]

                = -11150 J/mol

Converting Joules to kJ

-11149 J/ mol * 1 KJ / 1000 J = -11.15 kJ/mol

Therefore the delta Go = -11.15 kJ/mol