Citrate synthase catalyzes an aldo - type condensation. the kinetic mechanism is
ID: 35201 • Letter: C
Question
Citrate synthase catalyzes an aldo - type condensation. the kinetic mechanism is a random-sequential one where either substrate can bind first.
The free energy change for the hydrolusis of acetyl coA is G'=-43kj/mol. Howerver the G' valur for the hydrolysis of the citryl coA intermediate in the CS reaction is significantly different from the value. Estimate this calue by assuming it is the same value as that for hydrolysis of succinyl-coA ( this calue can be calculated from the known value of G'- +1.7 kJ/mol) for the succinate thiokinase reaction)
How can you ( very briefly account for the difference in G' values for hydrolysis of AcCoA and citryl-coA?
Explanation / Answer
the value of citroyl coa is -31.5kJ/mol. this values pulls the reaction in the forward direction. also, ATP hydrolysis is involved in the hydrolysis of acetyl coa thus, the the overall fre energy change for the reaction is much higher than citroyl coa