[oneka]

Could someone help me with this two questions?


pyruvate kinase transfer a phosphate group from phosphoenolpyruvate to ADP, forming pyruvate and ATP. The reaction catalyzed by this enzyme is essentially irreversible. Whicho of the following is the best explanation for the irreversible nature of this reaction?
(A) The binding of pyruvate to the active site is very weak relative to the binding of phosphoenolpyruvate.
(B) The reaction is coupled to the pyruvate dehydrogenase reaction.
(C) the hydrolisis of ATP is highly favorable.
(D) The cange in free energy for the overall reaction is large and negative.
(E) There is a different enzyme in the cell which synthesizes phosphoenolpyruvate


Which of the following is most likely to happen to the concentration of lactate in the cell?

(A) it will remain the same
(B) it will increase initially and then decreaso to control values as equilibrium is achieved
(C) It will increase to a new steady-state level
(D) It will decrease because the cell secretes the lactate
(E)It will decrease because the cell uses lactate to syntesize glucose