
1. The synthesis of the amino acid glutamine driven by (or coupled to) the simultaneous hydrolysis of ATP to ADP by the enzyme glutamine synthetase See Hammes & Hammes-Schiffer, Appendix 4 (app4.pdf) for tabulated data for these reactions.) glutamate NH3glutamine H20 ATP H20ADP phosphate (a) For both reactions, use the table data to determine the Gibbs reaction energy at the standard state, Δ,G°, and the equilibrium constant, Keg. If you were to mix the reactants up in equimolar amounts, what would be the expected composition of the mixture at equilibrium? Assume here that the two reactions occur independently. (b) If the two reactions occur simultaneously, as catalyzed by the enzyme determine the Gibbs reaction energy at the standard state, A,G’, and the equiibrium constant, Keq Here you should add the two reactions up to make a coupled overall reaction. Compare these results with those from (1) above (c) For future consideratio n when we discuss enzyme catalysis: how does glutamine synthetase achieve the result from (b)? Suggest a possible mechanism





