Question: Glycogen phosphorylase catalyzes the removal of glucose 1-phosphate from glycogen: Glycogen(n) + …

Glycogen phosphorylase catalyzes the removal of glucose
1-phosphate from glycogen:
Glycogen(n) + Pi ⇄ Glycogen(n-1) + glucose 1-phosphate ΔG°’ = +3.1
kJ/mol

a) Comment upon the standard free energy for this reaction.

b) Using the value of ΔG°’, calculate the value of the
equilibrium constant for this reaction (hint: removal of a glucose
unit from glycogen does not change the concentration of
glycogen).

c) Using the value of K, calculate the equilibrium ratio of [Pi]
to [glucose 1-phosphate].

d) The observed physiological ratio of [Pi] to [glucose
1-phosphate] is 100:1. Under these conditions, calculate ΔG under
physiological conditions.

e) Comment on the difference between the equilibrium and
physiological ratios, assuming that all of the glucose 1- phosphate
formed eventually enters the glycolysis pathway.