late, 50% of the earned points will be taken as a penalty. Total point value: 25 pts
Questions 1 and 2 are concerned with the action of citrate synthase. This enzyme is responsible for the reaction
of oxaloacetate with acetyl-CoA to form citrate and HSCoA (coenzyme A). The actual structures of these
molecules are not relevant to the problems, but citrate is a molecule common to several metabolic pathways.
1) If the standard free energy change ($\Delta G^\circ$) of this reaction is -31.5 kJ/mol, calculate the equilibrium
constant for the reaction at 37°C. (5 pts)
2) In living E. coli cells, [oxaloacetate] = 7mM (millimolar), [acetyl-CoA] = 0.8mM, [citrate] = 4mM, and
[HSCoA] = 1.5mM. Is the reaction at equilibrium within living E. coli cells? Show your work and
briefly explain your answer. (5 pts)